DOWNLOAD PDF KCM 115Z7 WHEEL LOADER ISUZU 6WG1 ENGINE Shop Manual PN 93216-00570

115Z7

93216-00570 May 2013

SHOP MANUAL

SHOP MANUAL

General Information Function & Structure

WHEEL LOADER

115Z7 General Information Function & Structure

Printed in Japan (K) ( アメリカ用 )

93216-00570

©2013 KCM Corporation. All rights reserved.

Powered by ISUZU 6WG1 ENGINE Serial No. 11J1-5001 and up

93216-00570

SHOP MANUAL (Function & Structure) INTRODUCTION........................................................................................................................... IN-01~02 SECTION 1

GENERAL

Group 1

Specifications ............................................................................................................. T1-1

Group 2

Component Layout..................................................................................................... T1-2

Group 3

Component Specifications ......................................................................................... T1-3

SECTION 2 SYSTEM Group 1

Controller.................................................................................................................... T2-1

Group 2

Control System........................................................................................................... T2-2

Group 3

ECM System .............................................................................................................. T2-3

Group 4

Hydraulic System ....................................................................................................... T2-4

Group 5

Electrical System........................................................................................................ T2-5

SECTION 3 COMPONENT OPERATION Group 1

Pump Device.............................................................................................................. T3-1

Group 2

Control Valve .............................................................................................................. T3-2

Group 3

Cooling Fan................................................................................................................ T3-3

Group 4

Steering Pilot Valve .................................................................................................... T3-4

Group 5

Steering Valve ............................................................................................................ T3-5

Group 6

Pilot Valve................................................................................................................... T3-6

Group 7

Charging Circuit ......................................................................................................... T3-7

Group 8

Drive Unit.................................................................................................................... T3-8

Group 9

Axle ............................................................................................................................ T3-9

Group 10 Brake Valve .............................................................................................................. T3-10 Group 11 Others....................................................................................................................... T3-11 INDEX ATTACHMENT Hydraulic Circuit Diagram & Brake Circuit Diagram Electrical Connection Diagram Electrical Wiring Diagram - Front Chassis Electrical Wiring Diagram - Rear Chassis Electrical Wiring Diagram - Floor (Rear & Side Console) Electrical Wiring Diagram - Floor (Front Console) Electrical Wiring Diagram - CAB All information, illustrations and specifications in this manual are based on the latest product information available at the time of publication. The right is reserved to make changes at any time without notice.

INTRODUCTION To The Reader This manual is written for trained and skilled technicians to provide technical information needed to maintain and repair this machine.

y If you have any questions or comments, at if you found any errors regarding the contents of this manual, please contact using “Service Manual Revision Request Form” at the end of this manual. (Note: Do not tear off the form. Copy it for usage.):

y Be sure to thoroughly read this manual for correct product information and service procedures.

Additional References Please refer to the other materials (Operation and Maintenance Manual, parts catalog, engine technical material and Kawasaki Shop Manual, etc.) in addition to this manual.

Manual Composition This manual consists the Technical Manual, the Workshop Manual and the Engine Manual.

y Information included in the Workshop Manual: Technical information needed for maintenance and repair of the machine, tools and devices needed for maintenance and repair, maintenance standards, and removal / installation and assembly / disassembly procedures.

y Information included in the Technical Manual: Technical information needed for machine pre-delivery and delivery, operation and activation of all devices and systems, operational performance tests, and troubleshooting procedures.

y Information included in the Engine Manual: Technical information needed for machine pre-delivery and delivery and maintenance and repair of the engine, operation and activation of all devices and systems, troubleshooting and assembly / disassembly procedures.

Page Number Each page has a number, located on the center lower part of the page, and each number contains the following information: Example: y Technical Manual: T 1-3-5 T 1 3 5

y Workshop Manual: W 1-3-2-5 W 1 3 2 5

Technical Manual Section Number Group Number Consecutive Page Number for Each Group

IN-01

Workshop Manual Section Number Group Number Sub Group Number Consecutive Page Number for Each Group

INTRODUCTION Safety Alert Symbol and Headline Notations In this manual, the following safety alert symbol and signal words are used to alert the reader to the potential for personal injury or machine damage.

CAUTION:

Indicated potentially hazardous situation which could, if not avoided, result in personal injury or death.

This is the safety alert symbol. When you see this

IMPORTANT: Indicates a situation which, if not conformed to the instructions, could result in damage to the machine.

symbol, be alert to the potential for personal injury.

Never fail to follow the safety instructions prescribed along with the safety alert symbol.

The safety alert symbol is also used to draw attention to component/part weights.

To avoid injury and damage, be sure to use appropriate lifting techniques and equipment when lifting heavy parts.

NOTE:

Indicates supplementary technical information.

Units Used Example: 24.5 MPa (250 kgf/cm2, 3560 psi)

SI Units (International System of Units) are used in this manual. MKSA (Meter, Kirogram, Second, Ampere) system units and English units are also indicated in parentheses just behind SI units.

A table for conversion from SI units to other system units is shown below for reference purposes.

Quantity

To Convert From

Into

Multiply By

Length

mm

in

0.03937

mm

ft

0.003281

L

US gal

0.2642

US qt

1.057

3

Volume

L 3

yd

1.308

kg

lb

2.205

m Weight Force Torque Pressure Power

N

kgf

0.10197

N

lbf

0.2248

N·m

kgf·m

0.10197 2

MPa

kgf/cm

10.197

MPa

psi

145.0

kW

PS

1.360

kW

HP

1.341

Temperature

°C

°F

°C×1.8+32

Velocity

km/h

mph

0.6214

-1

min

rpm

1.0

L/min

US gpm

0.2642

mL/rev

cc/rev

1.0

Flow rate

NOTE: The numerical value in this manual might be different from the above-mentioned table.

IN-02

SECTION 1

GENERAL ―CONTENTS― Group 1 Specifications Specifications ...........................................T1-1-1

Combination Valve (Brake Manifold Valve) ........................T1-2-22 Steering Valve ........................................T1-2-22

Group 2 Component Layout

Flow Regualtor Valve..............................T1-2-23

Main Component (Overview) ....................T1-2-1

Ride Control Valve (Option) ....................T1-2-23

Main Component (Power System) ............T1-2-2

Secondary Steering Pump (Option).........T1-2-23

Main Component (Hydraulic System) ........T1-2-3 Electric Component Layout

Group 3 Component Specifications

(Front Chassis) .....................................T1-2-4

Engine......................................................T1-3-1

Electric Component Layout (Rear Grill).....T1-2-5

Engine Accessories ..................................T1-3-4

Electrical System (Cab) ............................T1-2-6

Hydraulic Component ...............................T1-3-6

Controller and Relays............................T1-2-7

Electrical Component.............................. T1-3-11

Right Console .......................................T1-2-8 Monitor and Switches ............................T1-2-9 Monitor Panel ......................................... T1-2-10 Multi-Function Monitor/ Air Conditioner Switch Panel ............... T1-2-11 Joystick Steering Controls ...................... T1-2-11 Electrical System (Around Battery Box) .. T1-2-12 Electrical System (Around Hydraulic Tank) ...................... T1-2-13 Electrical System (Around Fuel Tank) ..... T1-2-14 Electrical System (Rear Chassis Center Frame).............. T1-2-15 Engine.................................................... T1-2-16 Exhaust Filter ...................................... T1-2-17 Hydraulic Pump ...................................... T1-2-18 Main Pump.......................................... T1-2-18 Accessory Pump ................................. T1-2-19 Transmission and Torque Converter Assembly ............................................ T1-2-20 Multiple Control Valve............................. T1-2-21 Unloader Valve (Brake Charge Valve) ..... T1-2-22

115Z7 F&S

(Blank)

115Z7 F&S

SECTION 1 GENERAL Group 1 Specifications Specifications

115Z7-AK-RVT

Bucket Capacity: heaped Operating Weight Tipping Load (Full Turn) Engine A: Overall Length B: Overall Width (Bucket) C: Overall Height D: Wheel Base E: Tread F: Ground Clearance G: Bucket Hinge Height H: Dumping Clearance (45 °) I: Dumping Reach (45 °) R1: Minimum Rotation Radius R2: Minimum Rotation Radius Travel Speed Forward/Reverse Transmission Speeds (F/R) Articulation Angle (Left/Right) deg Tire Size

m3 (Y3) kg (lbs) kg (lbs)

6.3 (8.3) 47280 (104230) 27610 (60870) ISUZU 6WG1 11370 (450) 3770 (150) 4195 (165) 4150 (165) 2650 (105) 545 (20) 5040 (200) 3270 (130) 2035 (80) 7545 (295) 8870 (350) 36.0 / 22.8 (22.4 / 14.1) 4/3 37 35/65R33, Radial

mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) mm (in) km/h (mph) (°) -

NOTE: These specifications are subject to change without notice.

T1-1-1

SECTION 1 GENERAL Group 1 Specifications (Blank)

T1-1-2

SECTION 1 GENERAL Group 2 Component Layout Main Component (Overview)

115TNED-01-02-01

115TNED-01-02-02

12345-

Bucket Bell Crank (Lever) Bucket Cylinder Front Combination Light Front Work Light

678910-

Rear Work Light Rear Combination Light Lift Arm (Boom) Cylinder Lift Arm (Boom) Bucket Link

11- Cab 12- ROPS (Roll Over Protective Structure) 13- Steering Cylinder 14- Battery Box

T1-2-1

15161718-

Hydraulic Tank Exhaust Pipe Counterweight Precleaner (Option)

SECTION 1 GENERAL Group 2 Component Layout Main Component (Power System)

115TNED-01-02-03

123456-

Front Axle 2nd Propeller Shaft (Front) Transmission 3rd Propeller Shaft (Rear) Rear Axle Torque Converter

789101112-

Engine Fuel Tank Engine Oil Filter Radiator Torque Converter Oil Cooler Charge Air Cooler

131415161718-

T1-2-2

Air Cleaner Exhaust Filter 1st Propeller Shaft (Main) Hydraulic Tank Bucket Cylinder Lift Arm (Boom) Cylinder

19202122-

Steering Cylinder Battery HVAC Condenser Fuel Cooler

SECTION 1 GENERAL Group 2 Component Layout Main Component (Hydraulic System)

115TNED-01-02-04

123456-

Fan Motor Coolant Sub Tank Valve Assy (for Accessory Pump Control) Brake Charge Valve (Unloader Valve) Combination Valve (Manifold Valve) Pilot Accumulator (for Loading and Brake Circuit) 7- Combination Valve (Auto Brake and Parallel/Tandem Switching Solenoid Valves) 8- Transmission Oil Filter 9- Stop Valve 10- Steering Pilot Valve (for Joystick Steering)

1112131415161718192021-

Brake Valve Ride Control Accumulator (Option) Ride Control Valve (Option) Exhaust Filter Regeneration Control Solenoid Valve Multiple Control Valve Pilot Valve Flow Regulator Valve Combination Valve (Reducing Valve) Steering Valve Steering Accumulator Priority Hammer Valve

T1-2-3

22232425262728-

Accessory Pump Main Pump Fuel Main Filter Water Separator (Option) Fuel Pre-filter Fan Control Valve Cooler Assembly (HVAC Condenser, Hydraulic Oil Cooler, Fuel Cooler) (See the previous page)

SECTION 1 GENERAL Group 2 Component Layout Electric Component Layout (Front Chassis)

11

1

3

2

10 11

4

9

8 6 5 7 115Z7-01-02-01

12345-

Lift Arm Angle Sensor Pressure Sensor (Bucket Tilt (Roll Back)) Pressure Sensor (Bucket Dump) Pressure Sensor (Lift Arm Raise) Horn

6789-

Pressure Sensor (Service Brake Secondary) Axle (Front) Oil Temperature Sensor Exhaust Filter Regeneration Control Solenoid Valve Ride Control Solenoid Valve (Option)

T1-2-4

10- Bucket Leveler (Proximity Switch) 11- Front Combination Light (Headlight, Turn Signal Light, Clearance Light, Hazard Light)

SECTION 1 GENERAL Group 2 Component Layout Electric Component Layout (Rear Grill)

1

5

2

3

4

115Z7-01-02-02

123-

Rear View Camera Backup Alarm Rear Working Lamp

4-

5-

Rear Combination Light (Turn Signal Light, Hazard Light, Tail Light, Brake Light, Backup Light) Outside Temperature Sensor

T1-2-5

SECTION 1 GENERAL Group 2 Component Layout Electrical System (Cab) 4 2

5

1

4

4 3 3

Machine Front

7 8 Machine Front

6 10 9 115TNED-01-02-29

12345-

Radio Upper Switch Panel (Optional) Speaker Rear Wiper Motor Cab Rear Working Light

678-

Front Wiper Motor Components Related with Monitor and Switches (Refer to T1-2-9) Components Related with Right Console (Refer to T1-2-8)

T1-2-6

9-

Components Related with Controllers and Relays (Refer to T1-2-7) 10- Components Related with Joystick Steering System (Refer to T1-2-11)

SECTION 1 GENERAL Group 2 Component Layout Controller and Relays

115TNED-01-02-17

123456789101112-

Monitor Controller Flasher Relay Air Conditioner Controller MC (Main Controller) (Main) MC (Main Controller) (Sub) ECM (Engine Control Module) Head Light Relay (Left) Head Light Relay (Right) High-Beam Relay Bucket Leveler Relay Back Lamp and Alarm Relay Work Light Relay (Front)

131415161718192021222324-

Work Light Relay (Rear) Right Turn Signal Light Relay Horn Relay Starter Cut Relay Parking Brake Relay 1 Parking Brake Relay 2 Loading Control Lever Lock Relay Brake Light Relay Load Dump Relay Neutral Relay Turn Signal Light Relay (Left) Washer Relay (Front)

T1-2-7

2526272829303132333435-

Wiper Relay (Rear) Washer Relay (Rear) Secondary Steering Relay (Option) Engine ECM Main Relay Cab Working Light Relay (Front) (Option) Cab Working Light Relay (Rear) Cigar Socket Relay Radio Relay (USA) Fuse Box MPDr. Connector Tech2 (Engine Diagnostic Tool) Connector

SECTION 1 GENERAL Group 2 Component Layout Right Console

Fingertip Control Type 4 3

5

2

20 6 7

8

9

1

10 11

12 21

19 22 18

13 14 15 17

16 115Z7-01-02-03

115Z7-01-02-04

Multi-Function Joystick Type 22

20

1

5

6 7 8

23

2410 11

12

4 18 21

19

17

123456789-

Auxiliary Control Lever (Optional) Bucket Control Lever Lift Arm Control Lever Turn Signal Switch Control Lever Lock Switch Declutch Position Switch Travel Mode Selector Switch Power Mode Switch Auxiliary

16

1011121314151617-

13 14 15 MNEC-01-044

MNEC-01-043

Fan Reverse Rotation Switch Hydraulic Coupler Switch (Optional) Auxiliary Secondary Steering Operation Check Switch (Optional) Exhaust Filter Switch Auxiliary Auxiliary Ride Control Switch (Optional)

T1-2-8

18192021222324-

Hold Switch Right Console Slide Lever DSS (Down Shift Switch) Horn Switch Quick Power Switch Multi-Function Joystick Lever Auxiliary

SECTION 1 GENERAL Group 2 Component Layout Monitor and Switches

7 3

4

5

8

9

6

2 1 10

115Z7-01-02-05

12345-

Hazard Switch Work Light Switch Parking Brake Switch Light Switch Rear Wiper Switch

6789-

Front Wiper Switch Monitor Panel (Refer to T1-2-10) Key Switch Multi-Function Monitor/Air Conditioner Switch Panel (Refer to T1-2-11)

T1-2-9

10- Throttle Pedal Limit Switch

SECTION 1 GENERAL Group 2 Component Layout Monitor Panel 21

22

1

2

20

3

4

5

19

6

7 8

18

9 10

17

11 16

15

12 13

14

12345678910-

Left Turn Signal Indicator High Beam Indicator Work Light Indicator Right Turn Signal Indicator Parking Brake Indicator Brake Oil Low Pressure Indicator Hydraulic Oil Level Indicator Low Steering Oil Pressure Indicator Transmission Warning Indicator Control Lever Lock Indicator

11121314151617181920-

Low Fuel Level Indicator Discharge Warning Indicator Fuel Gauge Multi Function Monitor Communication System Error Indicator Coolant Temperature Gauge Overheat Indicator Engine Warning Indicator Engine Oil Low Pressure Indicator Preheat Indicator

T1-2-10

21- Air Filter Restriction Indicator 22- Clearance Light Indicator

MNEC-01-001

SECTION 1 GENERAL Group 2 Component Layout Multi-Function Monitor/Air Conditioner Switch Panel

1234-

3

2

1

5-

4

6

5

7

8

Select / Confirm Knob Return to Previous Screen Return to Basic Screen Blower / Air Conditioner AUTO Switch Air Conditioner ON / OFF Switch

678-

Temperature / Mode Switch Defroster Switch Circulation / Fresh Air Switch

MNEC-01-006

Joystick Steering Controls 1 7 2

3

4

5

6 115Z7-01-02-06

123-

Forward / Reverse Switch Shift Up Switch Shift Down Switch

45-

Joystick Steering System Switch Armrest Adjust Handle

67-

T1-2-11

Armrest Lock Release Button Armrest Switch (Micro Switch)

SECTION 1 GENERAL Group 2 Component Layout Electrical System (Around Battery Box)

5 4

9

1

3 2 8

6

Battery Box

7 115TNED-01-02-06

1234-

Battery Relay Glow Relay Starter Relay Fusible Link (140A) x 2

567-

Fusible Link (70A) x 2 Battery Battery Disconnect Switch (Option)

T1-2-12

89-

Secondary Steering Pump (Option)(Refer to T1-2-23) Steering Pressure Switch (Option)

SECTION 1 GENERAL Group 2 Component Layout Electrical System (Around Hydraulic Tank) 1

4

5

2

3

115TNED-01-02-07

12-

Hydraulic Tank Hydraulic Oil Level Sensor

34-

Hydraulic Oil Temperature Sensor Window Washer Liquid Tank

5-

T1-2-13

Washer Tank Motor

SECTION 1 GENERAL Group 2 Component Layout Electrical System (Around Fuel Tank)

5

1 3 4

2 7

6

123-

Fan Motor Control Valve Hydraulic Fan Circuit Pressure Sensor Fan Speed Control Solenoid Valve

45-

Fan Reverse Rotation Control Solenoid Valve Fan Revolution Sensor

NOTE: Refer to Section 3 / Group 3 Cooling Fan System for more information.

T1-2-14

115TNED-01-02-08

67-

Fuel Tank Fuel Level Sensor

SECTION 1 GENERAL Group 2 Component Layout Electrical System (Rear Chassis Center Frame)

1

2

3

4

5

6 8

7

9

11

10

115TNED-01-02-09

1234-

Dropping Resistor Barometric Pressure Sensor Turbo Controller Loading Control Lever Lock Solenoid

567-

Parking Brake Solenoid Loading Control Pilot Primary Pressure Sensor Parking Brake Pressure Sensor

T1-2-15

8- Transmission Oil Filter 9- ECM 10- Lockup Solenoid

SECTION 1 GENERAL Group 2 Component Layout Engine

95TNED-01-02-9

1234-

EGR Valves Injector Connector Boost Temperature Sensor Boost Pressure Sensor

5678-

Glow Plug Cam Angle Sensor Turbocharger Overheat Switch

9101112-

T1-2-16

Coolant Temperature Sensor Intake Throttle Common Rail Pressure Sensor Fuel Temperature Sensor

13- Supply Pump 14- Crank Revolution Sensor 15- Engine Oil Pressure Sensor

SECTION 1 GENERAL Group 2 Component Layout Exhaust Filter

Arrow View A 95TNED-01-02-10

1-

Diesel Oxidation Catalyst (DOC) Exhaust Temperature Sensor

2-

Diesel Particulate Filter (DPF) Exhaust Temperature Sensor

3-

T1-2-17

Differential Pressure Sensor

SECTION 1 GENERAL Group 2 Component Layout Hydraulic Pump Main Pump

95TNED-01-02-11

12-

Steering and Loading Pump Proportional Reducing Valve

34-

Regulator 1 Regulator 2

NOTE: Refer to Section 3 / Group 1 Pump Device for more information.

T1-2-18

SECTION 1 GENERAL Group 2 Component Layout Accessory Pump

1

115TNED-01-02-12

1-

Pilot, Fan and Brake Pump

T1-2-19

SECTION 1 GENERAL Group 2 Component Layout Transmission and Torque Converter Assembly 5 4

2

1 6

7 4 8 18

9 3 11

12

13

14

15

16

17

10

115TNED-01-02-13

123456-

Torque Converter First Propeller Shaft (Main) Transmission Air Breather Proportional Solenoid Valve (For Lock-Up Clutch) Torque Converter Oil Temperature Sensor

789-

Modulator Valve Mount Direct Charge Valve Transmission Oil Temperature Sensor 10- Speed Sensor (Switch Proximity) 11- Transmission Control Valve

12- Proportional Solenoid Valve (For 1st Speed Clutch) 13- Proportional Solenoid Valve (For High Clutch) 14- Proportional Solenoid Valve (For 3rd Speed Clutch) 15- Proportional Solenoid Valve (For Reverse Clutch)

NOTE: Refer to Section 3 / Group 8 Drive Unit for more information.

T1-2-20

16- Proportional Solenoid Valve (For Low Clutch) 17- Proportional Solenoid Valve (For 2nd Speed Clutch) 18- Accumulator

SECTION 1 GENERAL Group 2 Component Layout Multiple Control Valve

95TNED-01-02-14

12-

Main Relief Valve Overload Relief Valve (Bucket: Rod Side)

34-

Overload Relief Valve (Bucket: Bottom Side) Overload Relief Valve (Lift Arm: Rod Side)

56-

NOTE: Refer to Section 3 / Group 2 Control Valve for more information.

T1-2-21

Solenoid Valve (for Ride Control) (Option) Bleed-off Compensation Valve

7-

Load Sensing Control (Negative Control) Relief Valve

SECTION 1 GENERAL Group 2 Component Layout Unloader Valve (Brake Charge Valve) and Combination Valve (Brake Manifold Valve) 12 3

1

4

1

5

6

2 6 7

10 9

13

11

115Z7-01-02-07

8 115TNED-01-02-15

1234-

Brake Accumulator Pressure Sensor (Loading Pilot Pressure) Pressure Sensor (Service Brake Primary Pressure) Loader Control Safety Lock Solenoid Valve

56789-

Parking Brake Solenoid Valve Combination Valve (Manifold Valve) Pressure Sensor (Parking Brake Lamp) Unloader Valve (Brake Charge Valve) Combination Valve (Solenoid Block)

NOTE: Refer to Section 3 / Group 7 Charging Unit for more information.

T1-2-22

10111213-

Auto Brake Solenoid Valve Parallel/Tandem Switching Solenoid Valve Reducing Valve Reducing Valve

SECTION 1 GENERAL Group 2 Component Layout Steering Valve

Flow Regulator Valve

90T4GB-01-02-20 90TNED-01-02-22 12-

Main Relief Valve Overload Relief Valve

12-

NOTE: Refer to Section 3 / Group 5 Steering Valve for more information.

T1-2-23

Pressure Sensor (Bucket Roll Back) Pressure Sensor (Bucket Dump)

3-

Pressure Sensor (Lift Arm (Boom) Raise)

SECTION 1 GENERAL Group 2 Component Layout Secondary Steering Pump (Option)

Ride Control Valve (Option)

90Z7-01-02-RC

1-

Solenoid Valve

90TNED-01-02-19

12-

T1-2-24

Electric Motor Gear Pump

3-

Relief Valve

SECTION 1 GENERAL Group 3 Component Specifications Engine Manufacturer

Isuzu Motors Limited

Model

6WG1

Type

Diesel, 4-Cycle, Water-cooled, Overhead Camshaft, Vertical In-Line, Direct Injection Type, Turbo Charger (for Intercooler)

No. of Cyl. - Bore × Stroke

6 - 147 × 154 mm (5.78 × 6.06 in)

Piston Displacement

15.68 L (956.85 in3)

Rated Output / Rated RPM (Net)

396 kW/1800 min-1 (531/1800 rpm)

Compression Ratio

16.5

Dry Weight

1150 kg (2535 lb)

Firing Order

1-5-3-6-2-4

Rotation Direction

Clockwise (Viewed from Fan Side)

T1-3-1

SECTION 1 GENERAL Group 3 Component Specifications Engine

COOLING SYSTEM

LUBRICATION SYSTEM

STARTING SYSTEM

Cooling Fan

Dia. 1118 mm (44 in), 7 Blades

Thermostat

Cracking Temperature at Atmospheric Pressure: 76.5°C (170°F)

Water Pump

Centrifugal Type

Lubrication Pump Type

Gear Pump

Oil Filter

Full-Flow Paper Element Type (Spin-On) and Remote Type

Oil Cooler

Integrated Water Cooled, 8-Stage Type

Motor

Reduction Type (Wet)

Voltage/Output

24 V / 7 kW

PREHEAT SYSTEM

Preheating Method

Glow Plug

ENGINE STOP SYSTEM

Stop Method

Fuel Shut Off (Electronic Control)

Type

Regulator Integrated AC Type, Brushless

Voltage/Output

24 V / 110 A

Type

Exhaust-Turbocharger Type

Type

Electronically Controlled Common Rail Type 6UHD Type

Governor

Electronic All Speed Control

Injection Nozzle

Electronic Multi-Hole Injector (G3 Type)

ALTERNATOR INTAKE AIR CHARGING SYSTEM FUEL SYSTEM

T1-3-2

SECTION 1 GENERAL Group 3 Component Specifications Engine

PERFORMANCE

Maximum Output Torque (Net)

2242 N·m (229 kgf·m, 1654 lbf·ft) at 1500 min-1

Valve Clearance (Intake / Exhaust) (When Cool)

0.4 / 0.4 mm (0.016 / 0.016 in)

No Load Speed

Slow : 900±50 RPM (min-1) Fast : 1850±50 RPM (min-1)

T1-3-3

SECTION 1 GENERAL Group 3 Component Specifications Engine Accessories Type

Hydraulically operated cooling fan with heat sensing system / Pressurized radiator

Weight

Radiator: 330 kg (730 lbs), Cooling Unit: 96 kg (212 lbs)

Radiator

Torque Converter Oil Cooler

Hydraulic Oil Cooler

Capacity

Coolant: 363 L (96 gal)/min

Lubricant: 207.5 L (55 gal)/ min

Lubricant: 121.5 L (32 gal)/ min

Required Heat Discharge

176 kw

135 kw

44.5 kw

Allowable Temperature

Inlet: 100°C (212°F) or lower

Inlet: 120°C (248°F) or lower

Inlet: 100°C (212°F) or lower

Deaeration Method

Sub Tank

-

-

-

-

COOLING SYSTEM

Cap Opening Pressure

2

50 kPa (0.5 kgf/cm , 7 psi)

Intercooler

Fuel Cooler

Capacity

(Compressed Air)

Fuel: 4.4 L (1.16 gal)/min

Required Heat Discharge

47.7 kw

1.8 kw

Allowable Temperature

Outlet: 45°C (113°F) or lower

Inlet: 80°C (176°F) or lower

T1-3-4

SECTION 1 GENERAL Group 3 Component Specifications Engine Accessories

BATTERY

Type

COM-8D

Cold Cranking Amps

1313 CCA

Voltage

12 V

Capacity

RC = 435 min (Discharge: 25 A at 80 °F)

Weight

60 kg (130 lb)×2

T1-3-5

SECTION 1 GENERAL Group 3 Component Specifications Hydraulic Component Type

Variable Piston Pump

Theoretical Displacement

80 cm3/rev (4.9 in3/rev) x 2

Rated Pressure

31.4 MPa (320 kgf/cm2, 4550 psi)

REGULATOR

Type

Hydraulic Pressure Operated Type

SOLENOID VALVE (MAIN PUMP)

Function

Main Pump Torque Control

Type

Variable Piston Pump

Theoretical Displacement

74 cm3/rev (4.5 in3/rev)

Type

Pilot Pressure Operated Type (2-Spools)

Main Relief Set-Pressure

31.4 MPa (320 kgf/cm2, 4550 psi)

Overload Relief Set-Pressure

37.3 MPa (380 kgf/cm2, 5400 psi) (Lift Arm and Bucket)

MAIN PUMP

ACCESSORY PUMP MULTIPLE CONTROL VALVE

T1-3-6

SECTION 1 GENERAL Group 3 Component Specifications Hydraulic Component FAN MOTOR

Theoretical Displacement

FAN CONTROL SOLENOID Function VALVE RIDE CONTROL ACCUMULATOR

63.1 cm3/rev (3.85 in3/rev) Fan Motor Reverse Control, Fan Motor Speed Control

Capacity

6.0 L (366 in3)

Charging Pressure N2

4.2 MPa (42.8 kgf/cm2, 609 psi) at 20 °C Cut In Pressure : 6.9 MPa (70 kgf/cm2, 995 psi)

CHARGING (UNLOADER) VALVE

Charging Pressure

MANIFOLD VALVE (COMBINATION VALVE)

Function

Parking Brake ON/OFF Control Lock the Front Attachment

SOLENOID VALVE (COMBINATION VALVE)

Function

Parallel/Tandem Circuit Switching Control Auto Brake Control

Capacity

3.0 L (183 in3) x 2

Charging Pressure N2

2.94 MPa (30 kgf/cm2, 426 psi) at 20 °C (68 °F)

Type

Flow Amp Type

Main Relief Set Pressure

27.4 MPa (279 kgf/cm2, 3970 psi)

Over Load Relief SetPressure

32.5 MPa (331 kgf/cm2, 4710 psi) at 15 L/min (4 US gpm)

STEERING PILOT VALVE

Type

Pilot Pressure Operated Type

STEERING ACCUMULATOR

Capacity

0.2 L (12 in3)

Charging Pressure N2

5 MPa (51 kgf/cm2,725 psi) at 20 °C (68 °F)

BRAKE VALVE

Brake Pressure

4.4 MPa (45 kgf/cm2, 638 psi)

SERVICE BRAKE ACCUMULATOR

STEERING VALVE

Cut Out Pressure : 11.8 MPa (120 kgf/cm2, 1706 psi)

T1-3-7

SECTION 1 GENERAL Group 3 Component Specifications Hydraulic Component Type

Planetary Gear Type Forward 1st : 3.995 Forward 2nd : 2.141

TRANSMISSION

Forward 3rd : 1.274 Gear Ratio

Forward 4th : 0.661 Reverse 1st : 3.642 Reverse 2nd : 1.942 Reverse 3rd : 1.155

STANDARD AXLE (FRONT/REAR)

PARKING BRAKE

STANDARD PROPELLER SHAFT

Model

Gear Reduction Type (Outboard Planetary Gear Reduction)

Brake Type

Wet Multiplate Outboard Disk Brake

Brake Pressure

3.96 MPa (40.4 kgf/cm2, 575 psi)

Final Reduction Gear Ratio

24.022

Spring Apply Hydraulic Release Pressure

3.5 MPa (35.7 kgf/cm2, 508 psi)

Type

Cruciform Joint Type Main (1st): 226 mm (8.9 in)

Dimension between Universal Joint Centers

Front (2nd): 1497.85 mm (59 in) Rear (3rd): 526 mm (20.7 in)

T1-3-8

SECTION 1 GENERAL Group 3 Component Specifications Hydraulic Component

CYLINDER

Lift Arm (Boom)

Bucket

Steering

Rod Diameter

120 mm (4.7 in)

100 mm (3.9 in)

60 mm (2.4 in)

Cylinder Bore

190 mm (7.5 in)

160 mm (6.3 in)

100 mm (3.9 in)

Stroke

1132 mm (44.6 in)

767 mm (30.2 in)

720 mm (28.3 in)

Fully Retracted Length 1826 mm (71.9 in)

1317 mm (51.9 in)

1075 mm (42.3 in)

T1-3-9

SECTION 1 GENERAL Group 3 Component Specifications Hydraulic Component

HYDRAULIC FILTER

TRANSMISSION

Full-Flow Filter (Filtration)

β10≥2.0 (filters 50% or more particles 10 μm in diameter)

Suction Filter (Filtration)

105 μm (150 mesh)

Pilot Filter (Filtration)

150 mesh

Steering Filter (Filtration)

95 μm (200 x 40 mesh)

Transmission Oil Filter (Filtration)

β6≥75 (filters 98% or more particles 6 μm in diameter)

T1-3-10

SECTION 1 GENERAL Group 3 Component Specifications Electrical Component ENGINE OIL PRESSURE SENSOR

Operating Pressure

48 kPa (0.5 kgf/cm2, 7 psi)

OVER HEAT SWITCH (Engine Accessory)

Operating Temperature

105 °C (221 °F)

FUEL LEVEL SENSOR

Resistance Value

Empty : 90+100 Ω, Full : 100-4 Ω

BATTERY RELAY

Voltage/Current

24 V/100 A

STARTER RELAY 2

Voltage

24 V

GLOW PLUG RELAY

Voltage

24 V

AIR FILTER RESTRICTION SWITCH

Operating Pressure

6.2±0.6 kPa (0.9±0.09 psi)

Voltage

24 V

Sound Pressure

111.5±6.5 dB (A) at 2 m

Operating Temperature

-30 to 120 °C (-22 to 248 °F)

HORN HYDRAULIC OIL TEMPERATURE SENSOR

T1-3-11

SECTION 1 GENERAL Group 3 Component Specifications Electrical Component

ILLUMINATION

AIR CONDITIONER

SECONDARY STEERING PUMP UNIT (OPTION)

Work Light

Halogen 24 V, 70 W (Cab Front, Rear)

Cab Light

24 V, 10 W x 2 + 24 V, 10 W

Head Light

Halogen 24 V, 75/70 W

Turn Signal Light

Front: 24 V, 25 W Rear: 24 V, 7.8 W

Clearance Light

24 V, 5 W

Tail Light

24 V, 0.84 W

Brake Light

24 V, 4.8 W

Refrigerant

R134 a

Cooling Ability

4.65 kW (15870 BTU) or More

Cool Air Volume

550 m3/h (19425 ft3/h) or More

Heating Ability

5.81 kW (19825 BTU) or More

Warm Air Volume

400 m3/h (14125 ft3/h) or More

Temperature Adjusting System

Electronic Type

Refrigerant Quantity

1000±50 g

Compressor Oil Quantity

160 cm3 (5.4 Ounces)

Type

Electric Motor Operated Type

Maximum Flow

20 L/min (5.28 gpm) at 16 MPa (163 kgf/cm2, 2320 psi)

Electric Motor Voltage

24 V, 6.6 kW

T1-3-12

SECTION 2

SYSTEM ―CONTENTS― Group 1 Controller

Shift Holding Control .......................... T2-2-44

Outline .....................................................T2-1-1

Lock Up Control.................................. T2-2-46

CAN Circuit ..............................................T2-1-2

Auto Brake Control ............................. T2-2-48

Group 2 Control System Outline .....................................................T2-2-1 Engine Control .........................................T2-2-4 Accelerator Pedal Failure Control..........T2-2-6 Auto-Warm Up Control ..........................T2-2-8 Engine Speed Regulator For Digging... T2-2-10 Speed Limit Control with Power Mode OFF ..................... T2-2-12 Traction Control .................................. T2-2-14 Load-Free Engine High Idle Limiter ..... T2-2-16 Engine Protection Control ................... T2-2-18 Pump Control ......................................... T2-2-21 Base Torque Control ........................... T2-2-22 Torque Decrease Control While Digging .................................. T2-2-24 Lift Arm Speed Multiplication Control ... T2-2-26 Transmission Control.............................. T2-2-28 Neutral Control.................................... T2-2-30 Forward/Reverse Switch Activation Control ............................ T2-2-32

Fan Control, Valve Control ..................... T2-2-51 Fan Speed Control ............................. T2-2-52 Fan Reverse Rotation Control............. T2-2-54 Lift Arm and Bucket Selection Circuit Control.................. T2-2-56 Exhaust Filter Manual Regeneration Control.......... T2-2-58 Exhaust Filter Auto Regeneration Control .............. T2-2-60 Ride Control (Option).......................... T2-2-62 Other Control ......................................... T2-2-65 Transmission Alarm Control ................ T2-2-66 Parking Brake Operation Indicator Control ............................. T2-2-68 Low Brake Oil Pressure Indicator Control ............................. T2-2-70 Low Steering Oil Pressure Indicator Control (Option) ................ T2-2-72 Lift Arm (Boom) Auto Leveler Height Kickout Control .................... T2-2-74 Lift Arm (Boom) Auto Leveler

Manual Speed Shift Control ................. T2-2-34

Lower Kickout Control ..................... T2-2-76

Automatic Speed Shift Control............. T2-2-36

Quick Power Mode Control ................. T2-2-78

Downshift Control................................ T2-2-38

Auto Idling Stop Control...................... T2-2-80

Speed Shift Delay Control ................... T2-2-40

Secondary Steering Control (Option) .. T2-2-82

Declutch Control ................................. T2-2-42 115Z7 F&S

Combined Electric and Hydraulic Control Circuit .............. T2-2-85 Bucket Auto Leveler Control................ T2-2-86 Lift Arm Float Control .......................... T2-2-88

Single Operation Circuit...................... T2-4-40 Combined Operation Circuit................ T2-4-42 Exhaust Filter Regeneration Control Circuit ................................. T2-4-46 Ride Control Circuit (Option)............... T2-4-48

Group 3 ECM System

Secondary Steering Circuit (Option).... T2-4-50

Outline .....................................................T2-3-1 Fuel Injection Control ...............................T2-3-2 Fuel Injection Volume Control................T2-3-4

Group 5 Electrical System Outline..................................................... T2-5-1

Fuel Injection Pressure Control .............T2-3-6 Fuel Injection Timing Control .................T2-3-8 Fuel Injection Rate and Frequency Control ...................T2-3-8 EGR Control........................................... T2-3-10 Preheating Control ................................. T2-3-12 Variable Turbocharger Control ................ T2-3-13 Exhaust Filter ......................................... T2-3-14 Exhaust Filter Regeneration Control ....... T2-3-16

Group 4 Hydraulic System Outline .....................................................T2-4-1

Main Circuit ............................................. T2-5-2 Electric Power Circuit (Key Switch: OFF)............................. T2-5-4 CAN Circuit .......................................... T2-5-6 Accessory Circuit (Key Switch: ACC) .... T2-5-8 Starting Circuit (Key Switch: START) .. T2-5-10 Neutral Engine Start Circuit ................ T2-5-12 Charging Circuit (Key Switch: ON) ...... T2-5-14 Surge Voltage Prevention Circuit ........ T2-5-18 Pilot Shut-Off Circuit (Key Switch: ON) ............................ T2-5-20 Auto Idling Stop Circuit ....................... T2-5-22

Pilot Circuit...............................................T2-4-2

Engine Stop Circuit............................. T2-5-24

Brake Priority Circuit .............................T2-4-4 Service Brake Circuit........................... T2-4-10

Monitor Circuit ....................................... T2-5-27

Parking Brake Circuit .......................... T2-4-12

Air Conditioner Circuit ........................ T2-5-28

Auto Brake Circuit ............................... T2-4-14 Lift Arm (Boom) / Bucket Operation Control Circuit.................................. T2-4-16 Fan Circuit .......................................... T2-4-20

Steering Column Monitor Circuit............. T2-5-31 Head Light Circuit............................... T2-5-32 Hazard Light Circuit (Key Switch: OFF)........................... T2-5-38

Main Circuit ............................................ T2-4-22

Turn Signal Light Circuit ..................... T2-5-40

Steering Priority Circuit ....................... T2-4-24

Horn Circuit (Key Switch: OFF)........... T2-5-42

Steering Operation Control Circuit ....... T2-4-28

Reverse Light / Buzzer Circuit ............ T2-5-44

Neutral Circuit ..................................... T2-4-34

Brake Light Circuit .............................. T2-5-46

Flow Rate Control Circuit .................... T2-4-34

Parking Brake Circuit.......................... T2-5-48

Relief Circuit ....................................... T2-4-34 Other Circuits ...................................... T2-4-34 Pump Control Circuit ........................... T2-4-36 Parallel Circuit Flow Rate Control........ T2-4-38

Accessory Circuit ................................... T2-5-53 Work Light Circuit ............................... T2-5-54 Wiper Circuit ...................................... T2-5-56 Cab Light Circuit................................. T2-5-62 115Z7 F&S

SECTION 2 SYSTEM Group 1 Controller Outline The following controllers are provided in this machine in order to control functions. Each controller communicates by using the CAN circuit and sends or receives the required signal.

Controller Main Controller (MC Main) Main Controller (MC Sub) Engine Control Module (ECM) Monitor Controller Column Display Controller Air Conditioner Controller

Function Controls the engine, transmission and pumps.

Controls the fan and valves.

Controls the engine.

Displays the operating information and alarms on the monitor.

Controls the wiper and work lights. Displays the operating information and alarms with the gauge, buzzer, and alarm lights.

Controls the air conditioner.

fNOTE:

Refer to the following sections corresponding group for details of each controller control.

So-called Display Controller (DSZ) consists of Monitor Controller and Information Controller. Information Controller communicates with Maintenance Pro Dr. (MPDr.)

T2-1-1

Reference T2-2 T2-2 T2-3 T5-2 T2-5 T2-5, T5-7

SECTION 2 SYSTEM Group 1 Controller CAN Circuit CAN (Controller Area Network) is based on International Organization for Standardization (ISO) Standards of the serial communication protocol.

Two networks (CAN bus (4)), CAN 1 (1) and CAN 2 (5) are equipped for this machine.

CAN 1 (1) is used for the engine control. CAN 2 (5) is used for the accessories.

CAN bus (4) consists of two harnesses, CAN-H (High) (2) and CAN-L (Low) (3).

Each controller judges the CAN bus (4) level due to potential difference between CAN-H (High) (2) and CAN-L (Low) (3).

Each controller arranges the CAN bus (4) level and sends the signal and data to other controllers.

In addition, termination resistors (120 Ω) (17) are installed to both ends of CAN bus (4).

T2-1-2

SECTION 2 SYSTEM Group 1 Controller 2 1 3 4 2 5 3 TDAA-02-05-001

95TNED-02-01-01

1234-

CAN 1 CAN-H (High) CAN-L (Low) CAN Bus

5789-

CAN 2 ECM (Engine Controller) MC (Main Controller) (Main) MC (Main Controller) (Sub)

11121314-

T2-1-3

Monitor Controller MP (Maintenance Pro) Dr. Air Conditioner Controller Column Display Controller

15- Monitor Control Unit 16- Information Control Unit 17- Termination Resistor (120 Ω)

SECTION 2 SYSTEM Group 1 Controller (Blank)

T2-1-4

SECTION 2 SYSTEM Group 2 Control System Outline Main Controllers (MC) (Main, Sub) are used to control the machine operations. The signals from the accelerator pedal sensor, transmission, various sensors, and switches are sent to MC and processed in the logic circuit.

MC (Main, Sub) use the Controller Area Network (CAN) to communicate required signals to the Engine Control Module (ECM) which controls engine outputs, such as revolutions and power curve. (Refer to SYSTEM / ECM System.)

MC (Main, Sub) also sends signals to solenoid control valves to control the hydraulic system, such as pump volume and load.

MC (Main) receives signals from the shift switch, forward/ reverse lever, forward/reverse switch, forward/reverse selector switch, and transmission for machine movement and process them in the logic circuit.

MC (Main) also operates the forward/reverse clutch solenoid valves and speed range solenoid valves, and controls the transmission.

T2-2-1

SECTION 2 SYSTEM Group 2 Control System Engine Control, Pump Control, Transmission Control < Input Signal > Accelerator Pedal Sensor Driving Mode Switch Power Mode Selector Switch Pressure Sensor (Brake Secondary Pressure) Pressure Sensor (Parking Brake) Pump Delivery Pressure Sensor Declutch Position Switch Key Switch Joystick Steering System Switch Forward/Reverse Switch Shift Up Switch Shift Down Switch Downshift Switch Hold Switch Armrest Switch Machine Speed Sensor Engine Speed Sensor Brake Pedal (Right) Switch

J J J J

MC (Main)

J J J J J J J J J J J J J J

< Output Signal > Engine Control J Accelerator Pedal Failure Control J Auto-Warm Up Control J Forward/Reverse Operation Engine Speed Limiter J Engine Speed Regulator For Digging J Speed Limit Control with Power Mode OFF J Traction Control J Load-Free Engine High Idle Limiter J Engine Protection Control

Pump Control J Base Torque Control J Torque Decrease Control While Digging

Lift Arm Angle Sensor Pressure Sensor (Lift Arm Raise) Pressure Sensor (Bucket Roll Back) Pressure Sensor (Bucket Dump) Hydraulic Oil Temperature Sensor Torque Converter Oil Temperature Sensor

J J J J J J

MC (Sub)

Coolant Temperature Sensor Engine Speed Sensor DOC Exhaust Temperature Sensor DPF Exhaust Temperature Sensor

J J J J

ECM

Maintenance Pro Dr. (MPDr.) Monitor

J J

Monitor Controller

Transmission Control J Neutral Control J Forward/Reverse Switch Activation Control J Manual Speed Shift Control J Automatic Speed Shift Control J Downshift Control J Shift Holding Control J Speed Shift Delay Control J Declutch Control J Lock-Up Control J Auto Brake Control

I Controller Area Network (CAN) Column Display Controller

T2-2-2

SECTION 2 SYSTEM Group 2 Control System Fan Control, Valve Control, Other Controls < Input Signal > Accelerator Pedal Sensor Driving Mode Switch Power Mode Selector Switch Quick Power Switch Declutch Position Switch Pump Delivery Pressure Sensor Parking Brake Pressure Sensor Machine Speed Sensor Secondary Brake Circuit Pressure Sensor Joystick Steering System Switch Forward/Reverse Switch Shift Up Switch Shift Down Switch

J

MC (Main)

J J

< Output Signal > Valve Control J Exhaust Filter Manual Regeneration Control J Exhaust Filter Auto Regeneration Control

J J

Other Controls J Transmission Alarm Control J Parking Brake Operation Indicator Control J Overrun Alarm Control J Quick Power Mode Control J Auto Idling Stop Control

J J J J J J J J

Fan Reversing Switch Hydraulic Fan Circuit Pressure Sensor Primary Pilot Pressure Sensor Steering Pressure Switch Secondary Steering Pump Delivery Pressure Sensor (Option) Secondary Steering Check Switch (Option) Hydraulic Oil Temperature Sensor Torque Converter Oil Temperature Sensor Lift Arm Angle Sensor Lift Arm Raise Pressure Sensor Bucket Dump Pressure Sensor Bucket Roll Back Pressure Sensor Refrigerant Pressure Sensor Primary Brake Circuit Pressure Sensor

J

Coolant Temperature Sensor Engine Speed Sensor DOC Exhaust Temperature Sensor DPF Exhaust Temperature Sensor Exhaust Filter Switch

J

Maintenance Pro Dr. (MPDr.) Monitor

J

MC (Sub)

J J J J

Fan Control, Valve Control J Fan Speed Control J Fan Reverse Rotation Control J Lift Arm and Bucket Selection Circuit Control J Ride Control (Option) J Lift Speed Increase While Raising Lift Arm

J J J

Other Controls J Low Brake Oil Pressure Indicator Control J Low Steering Oil Pressure Indicator Control (Option) J Lift Arm Auto Leveler Height Kickout Control J Lift Arm Auto Leveler Lower Kickout Control J Secondary Steering Control (Option)

J J J J J J

ECM

J J J J

J

Monitor Controller J Controller Area Network (CAN) Column Display Controller

T2-2-3

SECTION 2 SYSTEM Group 2 Control System Engine Control The engine control consists of the followings. x Accelerator Pedal Failure Control x Auto-Warm Up Control x Engine Speed Regulator For Digging x Speed Limit Control with Power Mode OFF x Traction Control x Load-Free Engine High Idle Limiter x Engine Protection Control

T2-2-4

SECTION 2 SYSTEM Group 2 Control System Engine Control System Layout

115TNED-02-02-01

a-

Brake Pedal Position: Lightly applied

b-

OFF

1234567891011121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Air Conditioner Controller Maintenance Pro (MP) Dr. Monitor Monitor Controller Engine Control Module (ECM) Engine Exhaust Temperature Sensor Engine Speed Sensor (Backup) Main Controller (MC) (Sub)

15- Coolant Temperature Sensor 16- Transmission 18- Torque Converter Oil Temperature Sensor 19- Engine Speed Sensor 21- Machine Speed Sensor 22- Shift Up Switch 23- Shift Down Switch 24- Forward Position 25- Neutral Position 26- Reverse Position 27- Forward/Reverse Switch 28- Joystick Steering System Switch

c-

Brake Pedal Position: Fully applied

29303132-

Pump Delivery Pressure Sensor Torque Control Solenoid Valve Parking Brake Solenoid Valve Pressure Sensor (Parking Brake) Parking Brake Switch Declutch Position Switch Power Mode Selector Switch Travel Mode Selector Switch AUTO 2 Mode Manual Mode AUTO 1 Mode Starter Key Switch

3334353637383940-

T2-2-5

41- Hydraulic Oil Temperature Sensor 42- Pressure Sensor (Boom Raise) 43- Pressure Sensor (Bucket Roll Back) 44- Brake Pedal (Left) 45- Pressure Sensor (Brake Secondary Pressure) 46- Brake Pedal (Right) 47- Brake Pedal (Right) Switch

SECTION 2 SYSTEM Group 2 Control System Accelerator Pedal Failure Control Purpose: The accelerator pedal control controls the engine speed according to the accelerator pedal angle (1).

A E

Operation: 1. Main Controller (MC) (Main) (3) receives the signals from accelerator pedal (1) and responds by sending a signal to Engine Control Module (ECM) (10) via Controller Area Network (CAN) communication (5) based on the accelerator pedal angle.

F G B C

2. ECM (10) controls the engine speed by responding to CAN signal (5) from MC (Main) (3).

D TNED-02-02-009

- In case of abnormal sensor signal detection 3. When the signal from accelerator pedal sensor (2) is out of acceptable range, MC (Main) (3) sends a backup signals to ECM (10).

A - Engine Speed B - Accelerator Pedal Position C - Accelerator Pedal Position: Not applied D - Accelerator Pedal Position: Fully applied

4. ECM (10) limits the engine speed to specified value 1000 min-1 (RPM) (F).

5. When accelerator pedal sensor (2) fails and has to be replaced, the engine RPM control will be returned to the accelerator pedal by doing the following.

1) Turn the key switch (40) OFF. 2) Be sure the key switch (40) is OFF for at least 10 seconds.

3) Turn the key switch (40) ON. The RPM's should now be controlled by the accelerator pedal sensor.

6. After the above procedure 5. has been done, ECM (10) will recognize the signal coming from MC (Main) (3) as provided from accelerator pedal sensor (2), according to the angle of the pedal, and the engine RPM's will be controlled by accelerator pedal (1).

NOTE: If a signal from accelerator pedal sensor (2)

cannot be sent to MC (Main) (3) due to the sensor circuit problem, an auxiliary connector is available to connect the accelerator pedal sensor to send the signal directly from the pedal to ECM (10). This enables the engine to run in proportion to the accelerator pedal angle.

T2-2-6

High Idle Speed 1850 min-1 (RPM) F - Limited RPM's (1000 min-1 (RPM)) G - Low Idle Speed (900 min-1 (RPM)) E-

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-03

a-

Brake Pedal Position: Lightly applied

b-

OFF

1234567891011121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Air Conditioner Controller Maintenance Pro (MP) Dr. Monitor Monitor Controller Engine Control Module (ECM) Engine Exhaust Temperature Sensor Engine Speed Sensor (Backup) Main Controller (MC) (Sub)

15- Coolant Temperature Sensor 16- Transmission 18- Torque Converter Oil Temperature Sensor 19- Engine Speed Sensor 21- Machine Speed Sensor 22- Shift Up Switch 23- Shift Down Switch 24- Forward Position 25- Neutral Position 26- Reverse Position 27- Forward/Reverse Switch 28- Joystick Steering System Switch

c-

Brake Pedal Position: Fully applied

29303132-

Pump Delivery Pressure Sensor Torque Control Solenoid Valve Parking Brake Solenoid Valve Pressure Sensor (Parking Brake) Parking Brake Switch Declutch Position Switch Power Mode Selector Switch Travel Mode Selector Switch AUTO 2 Mode Manual Mode AUTO 1 Mode Starter Key Switch

3334353637383940-

T2-2-7

41- Hydraulic Oil Temperature Sensor 42- Pressure Sensor (Boom Raise) 43- Pressure Sensor (Bucket Roll Back) 44- Brake Pedal (Left) 45- Pressure Sensor (Brake Secondary Pressure) 46- Brake Pedal (Right) 47- Brake Pedal (Right) Switch

SECTION 2 SYSTEM Group 2 Control System Auto-Warm Up Control A

Purpose: The auto-warm up control warms up the engine as shown below.

C

Operation: 1. MC (Sub) (14) receives the hydraulic oil temperature signal from hydraulic oil temperature sensor (41).

D

2. When key switch (40) is in the ON or START position and hydraulic oil temperature is below 0 °C (32 °F), MC (Main) (3) sends the target engine RPM signal to ECM (10) by using CAN communication (5).

3. ECM (10) increases the engine speed from 900 min-1 (RPM's) (E) to 1000 min-1 (RPM's) (D). This action permits quicker warm-up of the engine.

4. When all of the items under the topic below of "Deactivation Conditions" exist, MC (Main) (3) deactivates the auto-warm up control.

E B TNED-02-02-004

A - Engine Speed B - Target Engine Speed C - High Idle Speed 1850 min-1 (RPM)

5. At this point, ECM (10) returns the engine speed (min-1 or RPM) control back to the accelerator pedal (1) position.

Deactivation Conditions: x After key switch (40) has been in the ON or START position for 10 minutes or more x Hydraulic Oil Temperature: 30 °C (85 °F) or more x Coolant Temperature: 40 °C (105 °F) or more x Parking Brake: Released

NOTE: The engine low idle speed can be adjusted by Maintenance Pro Dr. (MPDr.) (7). The auto-warm up speed can be adjusted by MPDr. (7).

IMPORTANT: When adjusting the auto-idle speed, deactivate the auto-warm up control by using monitor panel (8). Make this adjustment only after waiting for 10 minutes to permit the systems to warm up.

T2-2-8

D - Auto- Warm Up Speed (1000 min-1 (RPM)) E - Low Idle Speed (900 min-1 (RPM))

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-05

a-

Brake Pedal Position: Lightly applied

b-

OFF

1234567891011121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Air Conditioner Controller Maintenance Pro (MP) Dr. Monitor Monitor Controller Engine Control Module (ECM) Engine Exhaust Temperature Sensor Engine Speed Sensor (Backup) Main Controller (MC) (Sub)

15- Coolant Temperature Sensor 16- Transmission 18- Torque Converter Oil Temperature Sensor 19- Engine Speed Sensor 21- Machine Speed Sensor 22- Shift Up Switch 23- Shift Down Switch 24- Forward Position 25- Neutral Position 26- Reverse Position 27- Forward/Reverse Switch 28- Joystick Steering System Switch

c-

Brake Pedal Position: Fully applied

29303132-

Pump Delivery Pressure Sensor Torque Control Solenoid Valve Parking Brake Solenoid Valve Pressure Sensor (Parking Brake) Parking Brake Switch Declutch Position Switch Power Mode Selector Switch Travel Mode Selector Switch AUTO 2 Mode Manual Mode AUTO 1 Mode Starter Key Switch

3334353637383940-

T2-2-9

41- Hydraulic Oil Temperature Sensor 42- Pressure Sensor (Boom Raise) 43- Pressure Sensor (Bucket Roll Back) 44- Brake Pedal (Left) 45- Pressure Sensor (Brake Secondary Pressure) 46- Brake Pedal (Right) 47- Brake Pedal (Right) Switch

SECTION 2 SYSTEM Group 2 Control System Engine Speed Regulator For Digging A

Purpose: The engine speed regulator for digging limits high idle speed and improves balance between tractive force and digging force according to the lift arm (boom) angle.

[Power Mode]

C

ON

E D

OFF

F G H

Operation: 1. Main Controller (MC) (Main) (3) receives signals from machine speed sensor (21), shift up switch (22) and shift down switch (23), and judges the currently selected shift range.

2. Engine speed sensor (19) sends the actual engine speed signals to MC (Main) (3).

1.4 1.5

3. MC (Main) (3) receives the signals from pump delivery pressure sensor (29) and power mode switch (35). MC (Sub) (14) receives the signal from lift arm angle sensor (41).

1.7

B

2.0

115TNED-02-02-13

A - Engine Speed (RPM) B - Lift Arm Angle (Voltage) C - High Idle Speed (Power Mode ON): 1850 min-1 (RPM) D - High Idle Speed (Power Mode OFF): 1550 min-1 (RPM) E,G - Specified RPM

4. When all of the items under the topic below of "Conditions" exist, MC (Main) (3) sends a target engine speed RPM (min-1) signal to Engine Control Module (ECM) (10) via CAN communication (5).

5. ECM (10) reduces and limits the engine RPM's (min-1) to the values (C)~(H) according to the power mode setting and lift arm angle as shown in the curved graph.

Conditions: x Forward/Reverse Switch (27): Forward (F) Position x Pump Delivery Pressure: High Pressure (Reference: 12 MPa (122 kgf/cm2, 1740 psi) or more) x Torque Converter Rotation Speed Ratio: Below specified value (Reference: Power mode ON: 40 % or less, Power mode OFF: 50 % or less) x Shift Up/Down Switch (22, 23): First range 4. When any of the item listed under "Deactivation Conditions" exist, MC (Main) (3) judges the machine is not digging and engine speed RPM limit control is defeasible.

F-

Specified RPM (When Lift Arm Is Level, Power Mode ON) (1500 min-1 (RPM)) H - Specified RPM (When Lift Arm Is Level, Power Mode OFF) (1370 min-1 (RPM))

Engine Speed according to Work Mode and Lift Arm Angle (Reference) (Unit: min-1 (RPM)) Power Mode Selector Switch (35) Highest Idle Speed (C, D) RPM at Specified Lift Arm Angle (at 1.7 V) (E, G) Specified RPM at Lift Arm Angle 0° (Level) (F, H)

OFF

ON

1550 1420

1850 1660

1370

1500

NOTE: Lift arm angle (indicated by voltage) is

Deactivation Conditions: x Forward/Reverse Switch (27): Reverse (R) or Neutral (N) Position x Pump Delivery Pressure: Low Pressure (Reference: 7.9 MPa (80.6 kgf/cm2, 1146 psi) or less) x Torque Converter Rotation Speed Ratio: Above specified value (Reference: Power mode ON: 50 % or more, Power mode OFF: 60 % or more) x Shift Up/Down Switch (22, 23): Second~Fourth range

T2-2-10

confirmed using Service Menu - Monitoring.

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-14

a-

Brake Pedal Position: Lightly applied

b-

OFF

1234567891011121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Air Conditioner Controller Maintenance Pro (MP) Dr. Monitor Monitor Controller Engine Control Module (ECM) Engine Exhaust Temperature Sensor Engine Speed Sensor (Backup) Main Controller (MC) (Sub)

15- Coolant Temperature Sensor 16- Transmission 18- Torque Converter Oil Temperature Sensor 19- Engine Speed Sensor 21- Machine Speed Sensor 22- Shift Up Switch 23- Shift Down Switch 24- Forward Position 25- Neutral Position 26- Reverse Position 27- Forward/Reverse Switch 28- Joystick Steering System Switch

c-

Brake Pedal Position: Fully applied

29303132-

Pump Delivery Pressure Sensor Torque Control Solenoid Valve Parking Brake Solenoid Valve Pressure Sensor (Parking Brake) Parking Brake Switch Declutch Position Switch Power Mode Selector Switch Travel Mode Selector Switch AUTO 2 Mode Manual Mode AUTO 1 Mode Starter Key Switch Lift Arm (Boom) Angle Sensor

333435363738394041-

T2-2-11

42- Pressure Sensor (Boom Raise) 43- Pressure Sensor (Bucket Roll Back) 44- Brake Pedal (Left) 45- Pressure Sensor (Brake Secondary Pressure) 46- Brake Pedal (Right) 47- Brake Pedal (Right) Switch

SECTION 2 SYSTEM Group 2 Control System Speed Limit Control with Power Mode OFF Purpose: This speed limiter limits the high idle speed according to propulsion load when the power mode is deactivated (OFF). Therefore, fuel consumption is reduced.

Speed Shift: Second or first

Operation: 1. Main Controller (MC) (Main) (3) receives a signal about machine speed from machine speed sensor (21).

2. Engine speed sensor (19) sends the actual engine speed data to MC (Main) (3).

A

3. When all of the items under the topic below of "Conditions" exist, MC (Main) (3) sends a target RPM (min-1) signal to Engine Control Module (ECM) (10) via CAN communication (5).

4. ECM (10) reduces and limits the engine speed to the specified value from the high idle speed according to CAN communication (5) when the engine speed is above the limited engine speed engaged by the speed limiter. x When the selected range is second or first, the engine speed is limited to a given value as indicated in the chart. The engine speed value is relative to the propulsion load.

Conditions: x Power Mode Selector Switch (35): OFF x Forward/Reverse Lever (23) or Forward/Reverse Switch (27): Forward Position (24) or Reverse Position (26)

B TNED-02-02-058

A - Engine Speed B - Propulsion Load

NOTE: The power mode can be set to ON or OFF by

NOTE: When third or fourth range is selected, the speed limit control with power mode OFF is deactivated.

NOTE: Speed limit control with power mode OFF is

activated by the signal from forward/reverse switch (27) when it is in use on the machine.

T2-2-12

using MPDr. (7) with key switch (40) ON or OFF.

In addition, the power mode ON/OFF status can be held or released with key switch (40) OFF until key switch (40) is turned ON.

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-19

a-

Brake Pedal Position: Lightly applied

b-

OFF

1234567891011121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Air Conditioner Controller Maintenance Pro (MP) Dr. Monitor Monitor Controller Engine Control Module (ECM) Engine Exhaust Temperature Sensor Engine Speed Sensor (Backup) Main Controller (MC) (Sub)

15- Coolant Temperature Sensor 16- Transmission 18- Torque Converter Oil Temperature Sensor 19- Engine Speed Sensor 21- Machine Speed Sensor 22- Shift Up Switch 23- Shift Down Switch 24- Forward Position 25- Neutral Position 26- Reverse Position 27- Forward/Reverse Switch 28- Joystick Steering System Switch

c-

Brake Pedal Position: Fully applied

29303132-

Pump Delivery Pressure Sensor Torque Control Solenoid Valve Parking Brake Solenoid Valve Pressure Sensor (Parking Brake) Parking Brake Switch Declutch Position Switch Power Mode Selector Switch Travel Mode Selector Switch AUTO 2 Mode Manual Mode AUTO 1 Mode Starter Key Switch

3334353637383940-

T2-2-13

41- Hydraulic Oil Temperature Sensor 42- Pressure Sensor (Boom Raise) 43- Pressure Sensor (Bucket Roll Back) 44- Brake Pedal (Left) 45- Pressure Sensor (Brake Secondary Pressure) 46- Brake Pedal (Right) 47- Brake Pedal (Right) Switch

SECTION 2 SYSTEM Group 2 Control System Traction Control Purpose: If the tire is ready to spin, by keeping the traction control switch ON, the engine speed is temporarily slowed down and tire spin is reduced. This increases tire life.

Operation: 1. Main Controller (MC) (Main) (3) receives signals from machine speed sensor (21), shift up switch (22), shift down switch (23), and forward/reverse switch (27).

2. MC (Main) (3) also receives an engine speed sensor signal (19) from Engine Control Module (ECM) (10) via CAN communication (5).

3. When all of the items under the topic below of "Conditions" exist, MC (Main) (3) sends a target RPM (min-1) signal to ECM (10) via CAN communication (5) depending on the machine speed increasing rate.

Conditions: x Machine keeps moving forward at 1st shift range for 100 msec or more. x Machine speed: 3.2 km/h (1.99 mph) or less x Actual engine speed: 1400 min-1 (RPM) or more Target Engine Speed: Machine Speed Increasing Rate (pulse/10 msec) 4 7 20

Target Engine Speed (min-1 (RPM)) 1500 1400 1000

4. Traction control is automatically deactivated after 0.5 seconds.

NOTE: Traction control function is turned ON at

shipment. This can be turned OFF via monitor (8), using Setting Menu - Transmission Setting - Traction Control.

Refer to the Operation Manual.

T2-2-14

SECTION 2 SYSTEM Group 2 Control System

115Z7-02-02-01

a-

Brake Pedal Position: Lightly applied

b-

OFF

1234567891011121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Air Conditioner Controller Maintenance Pro (MP) Dr. Monitor Monitor Controller Engine Control Module (ECM) Engine Exhaust Temperature Sensor Engine Speed Sensor (Backup) Main Controller (MC) (Sub)

15- Coolant Temperature Sensor 16- Transmission 18- Torque Converter Oil Temperature Sensor 19- Engine Speed Sensor 21- Machine Speed Sensor 22- Shift Up Switch 23- Shift Down Switch 24- Forward Position 25- Neutral Position 26- Reverse Position 27- Forward/Reverse Switch 28- Joystick Steering System Switch

c-

Brake Pedal Position: Fully applied

29303132-

Pump Delivery Pressure Sensor Torque Control Solenoid Valve Parking Brake Solenoid Valve Pressure Sensor (Parking Brake) Parking Brake Switch Declutch Position Switch Power Mode Selector Switch Travel Mode Selector Switch AUTO 2 Mode Manual Mode AUTO 1 Mode Starter Key Switch

3334353637383940-

T2-2-15

41- Hydraulic Oil Temperature Sensor 42- Pressure Sensor (Boom Raise) 43- Pressure Sensor (Bucket Roll Back) 44- Brake Pedal (Left) 45- Pressure Sensor (Brake Secondary Pressure) 46- Brake Pedal (Right) 47- Brake Pedal (Right) Switch

SECTION 2 SYSTEM Group 2 Control System Load-Free Engine High Idle Limiter A

Purpose: The load-free engine high idle limiter limits high idle speed when the hydraulic oil pump pressure is below a pressure that permits the system to operate efficiently, and the result is better fuel economy.

E F

Operation: 1. Main Controller (MC) (Main) (3) receives a signal from hydraulic oil pressure pump delivery pressure sensor (29).

H B

2. When all of the items under the topic below of "Conditions" exist, MC (Main) (3) sends an engine speed RPM (min-1) signal to Engine Control Module (ECM) (10) via CAN communication (5).

95TNED-02-02-011

A - Engine Speed B - Accelerator Pedal Position C - Accelerator Pedal Position: Not applied D - Accelerator Pedal Position: Fully applied

3. ECM (10) reduces and limits the engine RPM's as shown below under "Specified Value" (F) via CAN communication (5). x Specified Value (1730 min-1) (F): Pump delivery pressure is 12 MPa (122 kgf/cm2, 1740 psi) or less 4. When any of the item listed under "Deactivation Conditions" exist, ECM (10) returns the engine speed (min-1 or RPM) control back to the accelerator pedal (1) position.

D

C

EFH-

High Idle Speed 1850 min-1 (RPM) Specified Value (1730 min-1 (RPM)) Low Idle Speed (900 min-1 (RPM))

NOTE: When raising the lift arms, the pressure will

Deactivation Conditions: x Pump Delivery Pressure: Below specified value (Reference: 3 MPa (31 kgf/cm2, 435 psi) or more) x Forward/Reverse Lever (23): Forward Position (24) or Reverse Position (26) x (Machine Speed: 3 km/h (2 mph) or more)

NOTE: Load-free engine high idle limiter is activated/

deactivated by the signal of forward/reverse switch (27) when it is in use on the machine.

T2-2-16

typically be in mid-range pressures between 3 MPa (31 kgf/cm2, 435 psi) and 14 MPa (143 kgf/cm2, 2030 psi).

SECTION 2 SYSTEM Group 2 Control System

115Z7-02-02-02

a-

Brake Pedal Position: Lightly applied

b-

OFF

1234567891011121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Air Conditioner Controller Maintenance Pro (MP) Dr. Monitor Monitor Controller Engine Control Module (ECM) Engine Exhaust Temperature Sensor Engine Speed Sensor (Backup) Main Controller (MC) (Sub)

15- Coolant Temperature Sensor 16- Transmission 18- Torque Converter Oil Temperature Sensor 19- Engine Speed Sensor 21- Machine Speed Sensor 22- Shift Up Switch 23- Shift Down Switch 24- Forward Position 25- Neutral Position 26- Reverse Position 27- Forward/Reverse Switch 28- Joystick Steering System Switch

c-

Brake Pedal Position: Fully applied

29303132-

Pump Delivery Pressure Sensor Torque Control Solenoid Valve Parking Brake Solenoid Valve Pressure Sensor (Parking Brake) Parking Brake Switch Declutch Position Switch Power Mode Selector Switch Travel Mode Selector Switch AUTO 2 Mode Manual Mode AUTO 1 Mode Starter Key Switch

3334353637383940-

T2-2-17

41- Hydraulic Oil Temperature Sensor 42- Pressure Sensor (Boom Raise) 43- Pressure Sensor (Bucket Roll Back) 44- Brake Pedal (Left) 45- Pressure Sensor (Brake Secondary Pressure) 46- Brake Pedal (Right) 47- Brake Pedal (Right) Switch

SECTION 2 SYSTEM Group 2 Control System Engine Protection Control A

Purpose: Immediately after the engine starts, the increase of engine speed is limited and engine oil circulation is facilitated. This prevents the engine turbocharger from breakage.

E

Operation: 1. When starting the engine, Main Controller (MC) (Main) (3) receives the signal from coolant temperature sensor (15) and MC (Sub) (14) receives the signal from torque converter oil temperature sensor (18).

2. MC (Main) (3) responds by sending a signal corresponding to the target RPM's to Engine Control Module (ECM) (10) via Controller Area Network (CAN) communication (5) based on these temperature sensor signals.

F B C

D TNED-02-02-065

A - Engine Speed B - Accelerator Pedal Position C - Accelerator Pedal Position: Not applied D - Accelerator Pedal Position: Fully applied

3. ECM (10) keeps the engine at low idle speed 850 min-1) (RPM) for 30~40 seconds.

4. MC (Main) (3) automatically deactivates the engine protection control in a fixed period of time after the engine start.

5. At this point, ECM (10) slowly returns the engine speed (RPM or min-1) controlled by accelerator pedal (1) or other.

NOTE: Engine protection control is given a highest

priority over all other controls. Therefore, while it is being activated, the engine speed does not change by applying accelerator pedal (1) or any other operation.

T2-2-18

EF-

High Idle Speed 1850 min-1 (RPM) Low Idle Speed (900 min-1 (RPM))

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-64

a-

Brake Pedal Position: Lightly applied

b-

OFF

1234567891011121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Air Conditioner Controller Maintenance Pro (MP) Dr. Monitor Monitor Controller Engine Control Module (ECM) Engine Exhaust Temperature Sensor Engine Speed Sensor (Backup) Main Controller (MC) (Sub)

15- Coolant Temperature Sensor 16- Transmission 18- Torque Converter Oil Temperature Sensor 19- Engine Speed Sensor 21- Machine Speed Sensor 22- Shift Up Switch 23- Shift Down Switch 24- Forward Position 25- Neutral Position 26- Reverse Position 27- Forward/Reverse Switch 28- Joystick Steering System Switch

c-

Brake Pedal Position: Fully applied

29303132-

Pump Delivery Pressure Sensor Torque Control Solenoid Valve Parking Brake Solenoid Valve Pressure Sensor (Parking Brake) Parking Brake Switch Declutch Position Switch Power Mode Selector Switch Travel Mode Selector Switch AUTO 2 Mode Manual Mode AUTO 1 Mode Starter Key Switch

3334353637383940-

T2-2-19

41- Hydraulic Oil Temperature Sensor 42- Pressure Sensor (Boom Raise) 43- Pressure Sensor (Bucket Roll Back) 44- Brake Pedal (Left) 45- Pressure Sensor (Brake Secondary Pressure) 46- Brake Pedal (Right) 47- Brake Pedal (Right) Switch

SECTION 2 SYSTEM Group 2 Control System (Blank)

T2-2-20

SECTION 2 SYSTEM Group 2 Control System Pump Control The pump control consists of the following items. x Base Torque Control x Torque Decrease Control While Digging x Lift Arm Speed Multiplication Control

T2-2-21

SECTION 2 SYSTEM Group 2 Control System Base Torque Control Purpose: The base, or standard, torque control controls the hydraulic pump delivery flow rate in response to the engine speed changes due to variations in load so that the engine output power can be used more efficiently.

Q

Operation: 1. Main Controller (MC) (Main) (3) receives engine speed sensor signal (19) from Engine Control Module (ECM) (10) by CAN communication (5).

2. MC (Main) (3) sends a signal to hydraulic pump load torque control solenoid valve (30) relative to the actual engine speed as communicated by CAN communication (5) from ECM (10).

3. Torque control solenoid valve (30) delivers pilot pressure oil to the regulator depending on the signal received to control the pump delivery flow rate.

P TNED-02-02-024

NOTE: The calculated values of MC (Main) (3) are

different at low temperature and at high temperature.

NOTE: Refer to Torque Decrease Control While

P-

Dumping Bucket while dumping the bucket.

T2-2-22

Pressure

Q - Flow Rate

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-25

a-

Brake Pedal Position: Lightly applied

b-

OFF

1234567891011121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Air Conditioner Controller Maintenance Pro (MP) Dr. Monitor Monitor Controller Engine Control Module (ECM) Engine Exhaust Temperature Sensor Engine Speed Sensor (Backup) Main Controller (MC) (Sub)

15- Coolant Temperature Sensor 16- Transmission 18- Torque Converter Oil Temperature Sensor 19- Engine Speed Sensor 21- Machine Speed Sensor 22- Shift Up Switch 23- Shift Down Switch 24- Forward Position 25- Neutral Position 26- Reverse Position 27- Forward/Reverse Switch 28- Joystick Steering System Switch

c-

Brake Pedal Position: Fully applied

29303132-

Pump Delivery Pressure Sensor Torque Control Solenoid Valve Parking Brake Solenoid Valve Pressure Sensor (Parking Brake) Parking Brake Switch Declutch Position Switch Power Mode Selector Switch Travel Mode Selector Switch AUTO 2 Mode Manual Mode AUTO 1 Mode Starter Key Switch

3334353637383940-

T2-2-23

41- Hydraulic Oil Temperature Sensor 42- Pressure Sensor (Boom Raise) 43- Pressure Sensor (Bucket Roll Back) 44- Brake Pedal (Left) 45- Pressure Sensor (Brake Secondary Pressure) 46- Brake Pedal (Right) 47- Brake Pedal (Right) Switch

SECTION 2 SYSTEM Group 2 Control System Torque Decrease Control While Digging Purpose: The torque decrease control while digging (hydraulic load reduction) feature reduces pump oil flow and load so that the power from the engine can be applied to forward movement of the machine.

Operation: 1. When all of the items under the topic below of "Conditions" exist, Main Controller (MC) (Main) (3) judges that machine is digging and sets the target torque as follows: 1st shift range: 231 N·m (23.6 kgf·m, 170 lbf·ft) 2nd~4th shift range: 381 N·m (38.9 kgf·m, 281 lbf·ft) Conditions: x Torque Converter Rotation Speed Ratio: Below specified value (Reference: Power Mode ON: 40 % or less, Power Mode OFF: 50 % or less) x Forward/Reverse Switch (27): Forward Position (24) x Pump Delivery Pressure: High Pressure (Reference: 1st shift range: 12 MPa (122 kgf/cm2, 1740 psi) or more), 2nd ~ 4th shift range: 20.1 MPa (205 kgf/cm2, 2915 psi) or more)

5. When any of the following "Deactivation Conditions" exists, the Torque Decrease Control While Dumping Bucket is deactivated.

Deactivation Conditions: x Torque Converter Rotation Speed Ratio: Above specified value (Reference: Power Mode ON: 50 % or more, Power Mode OFF: 60 % or more) x Forward/Reverse Switch (27): Neutral Position (25) or Reverse Position (26) x Pump Delivery Pressure: Low Pressure (Reference: 1st shift range: 7.9 MPa (80.6 kgf/cm2, 1146 psi) or less, 2nd ~ 4th shift range: 10.1 MPa (103 kgf/cm2, 1465 psi) or less)

NOTE: Torque Decrease Control While Dumping Bucket is activated by the signal from forward/reverse switch (27) when it is in use on the machine.

NOTE: When the power mode selector switch (35) is ON,

2. MC (Sub) (14) receives a signal from lift arm angle sensor (48), and increases the target torque to obtain the optimum torque for the lift arm angle.

3. MC (Main) (3) sends a signal to torque control solenoid valve (30) depending on the target torque.

4. Torque control solenoid valve (30) adjusts the hydraulic oil flow delivery rate at the regulator relative to the electrical signal it receives from the MC (Main) (3).

T2-2-24

the engine speed is controlled according to the lift arm angle, and there is a case where the Torque Decrease Control While Dumping Bucket is deactivated.

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-26

a-

Brake Pedal Position: Lightly applied

b-

OFF

1234567891011121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Air Conditioner Controller Maintenance Pro (MP) Dr. Monitor Monitor Controller Engine Control Module (ECM) Engine Exhaust Temperature Sensor Engine Speed Sensor (Backup) Main Controller (MC) (Sub)

15- Coolant Temperature Sensor 16- Transmission 18- Torque Converter Oil Temperature Sensor 19- Engine Speed Sensor 21- Machine Speed Sensor 22- Shift Up Switch 23- Shift Down Switch 24- Forward Position 25- Neutral Position 26- Reverse Position 27- Forward/Reverse Switch 28- Joystick Steering System Switch

c-

Brake Pedal Position: Fully applied

29303132-

Pump Delivery Pressure Sensor Torque Control Solenoid Valve Parking Brake Solenoid Valve Pressure Sensor (Parking Brake) Parking Brake Switch Declutch Position Switch Power Mode Selector Switch Travel Mode Selector Switch AUTO 2 Mode Manual Mode AUTO 1 Mode Starter Key Switch

3334353637383940-

T2-2-25

41- Hydraulic Oil Temperature Sensor 42- Pressure Sensor (Boom Raise) 43- Pressure Sensor (Bucket Roll Back) 44- Brake Pedal (Left) 45- Pressure Sensor (Brake Secondary Pressure) 46- Brake Pedal (Right) 47- Brake Pedal (Right) Switch 48- Lift Arm Angle Sensor

SECTION 2 SYSTEM Group 2 Control System Lift Arm Speed Multiplication Control Purpose: This control delivers the oil from accessory pump (14) partly to the lift arm cylinder circuit to increase the lift arm raising speed at the specified arm angle or more.

Operation: 1. Main Controller (MC) (Sub) (2) receives signals from lift arm (boom) angle sensor (11) and boom raise pressure sensor (12).

2. MC (Main) (1) receives a signal from pump delivery pressure sensor (13).

3. When all of the items under the topic below of "Conditions" exist, MC (Main) (1) turns ON the lift arm speed multiplication solenoid valve.

4. Lift arm speed multiplication solenoid valve (16) blocks the pilot line to increase the pressure in priority hammer valve (17).

5. Then, the combined force of pressure P1 + the spring force becomes larger than pressure P2.

This connects the valve port to supply more oil to the loading circuit, and the excess oil will be sent to the fan motor circuit.

Conditions: x Lift Arm Raise Pressure: More than 1.2 MPa (12.2 kgf/ cm2, 174 psi) x Lift Arm Angle: 1.65 V < Voltage confirmed on monitor < 3.5 V x Pump Delivery Pressure: Less than 25 MPa (255 kgf/ cm2, 3626 psi) 6. When any of the items under the topic below of "Deactivation Conditions" exists, MC (Main) (1) turns OFF lift arm speed multiplication solenoid valve (16). The pressure at P2 side increases due to variable orifice, and becomes larger than P1 side.

This supplies the oil to the fan motor circuit.

Deactivation Conditions: x Lift Arm Raise Pressure: 1.0 MPa (10.2 kgf/cm2, 145 psi) or less x Lift Arm Angle (Voltage confirmed on monitor): 1.5 V or less, 3.6 V or more x Pump Delivery Pressure: More than 29 MPa (296 kgf/ cm2, 4206 psi)

NOTE: Lift arm angle is confirmed using Service Menu Monitoring.

T2-2-26

SECTION 2 SYSTEM Group 2 Control System When deactivated: Fan motor circuit Loading circuit

95Z7-02-02-03

When activated: Fan motor circuit Loading circuit

95Z7-02-02-04 12345-

Main Controller (MC) (Main) Main Controller (MC) (Sub) Column Display Controller Monitor Monitor Controller

678910-

Air Conditioner Controller Maintenance Pro Dr. (MPDr.) Engine Control Module (ECM) Transmission Controller Area Network (CAN)

1112131415-

T2-2-27

Lift Arm Angle Sensor Pressure Sensor (Boom Raise) Pump Delivery Pressure Sensor Accessory Pump Unloader (Brake Charge) Valve

16- Lift Arm Speed Multiplication Solenoid Valve 17- Priority Hammer Valve

SECTION 2 SYSTEM Group 2 Control System Transmission Control The transmission control consists of the following. x Neutral Control x Forward/Reverse Switch Activation Control x Manual Speed Shift Control x Automatic Speed Shift Control x Downshift Control x Speed Shift Delay Control x Declutch Control x Shift Holding Control x Lock Up Control x Auto Brake Control

T2-2-28

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-27

a-

Brake Pedal Position: Lightly applied

b-

OFF

c-

12345678911121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Monitor Monitor Controller Engine Control Module (ECM) Engine Downshift Switch (DSS) Hold Switch Transmission Torque Converter Oil Temperature Sensor

151617181920-

Engine Speed Sensor Main Controller (MC) (Sub) Machine Speed Sensor Lock Up Clutch Solenoid Valve Forward Clutch Solenoid Valve High Range Clutch Solenoid Valve Reverse Clutch Solenoid Valve Speed Shift Solenoid Valve Shift Up Switch Shift Down Switch Forward Position Neutral Position Reverse Position

28- Forward/Reverse Switch 29- Joystick Steering System Switch 30- Parking Brake Solenoid Valve 31- Pressure Sensor (Parking Brake) 32- Parking Brake Switch 33- Declutch Position Switch 34- Power Mode Selector Switch 35- Travel Mode Selector Switch 36- AUTO 2 Mode 37- Manual Mode 38- AUTO 1 Mode 39- Key Switch

21222324252627-

T2-2-29

Brake Pedal Position: Fully applied 40- Brake Pedal (Left) 41- Pressure Sensor (Brake Secondary Pressure) 42- Brake Pedal (Right) 43- Brake Pedal (Right) Switch 44- Lift Arm Angle Sensor 45- Pressure Sensor (Lift Arm Raise) 46- Pressure Sensor (Bucket Dump)

SECTION 2 SYSTEM Group 2 Control System Neutral Control Purpose: The neutral control deactivates the forward/reverse switch (28) operation and does not connect the transmission forward/reverse clutches when the parking brake is applied. Therefore, the parking brake is prevented from dragging.

6. Therefore, the forward/reverse clutch of transmission (13) is not engaged when the parking brake is applied, thus the parking brake is prevented from dragging.

7. When the parking brake is released, parking brake switch (32) is turned to "OFF", parking brake solenoid valve (30) sends pilot pressure oil to the parking brake unit to release it. It releases by compressing the parking brake spring with the piston.

1. Main Controller (MC) (Main) (3) receives a signal from parking brake pressure sensor (31) and armrest switch (option) (47).

2. MC (Main) (3) receives the signal from forward/ reverse switch (28).

8. MC (Main) (3) sends the input signal from forward/ reverse switch (28) to engage forward/reverse clutch solenoid valves (19, 21) of transmission (13) when the parking brake is released. (Pressure sensor (parking brake) (31) sends a signal that the parking brake release circuit has been pressurized, and the transmission can be operated.)

3. MC (Main) (3) reads the input signals from parking brake pressure sensor (31) and armrest switch (option) (47) when operating forward/reverse switch (28).

4. Parking brake solenoid valve (30) opens the circuit between the parking brake actuator and the hydraulic oil tank and engages the parking brake.

This is done via use of parking brake switch (32).

The parking brake is applied with spring force, and releases with oil pressure.

9. Therefore, the forward/reverse clutch of transmission (13) is engaged.

NOTE:

5. When the parking brake is applied and/or when the armrest is not properly lowered, MC (Main) (3) does not respond to the signal from forward/ reverse switch (28). Thus forward/reverse clutch solenoid valves (19, 21) of transmission (13) will not be energized when the parking brake is applied and the parking brake does not receive pressure to be released (pressure sensor at parking brake (31) is below the specified pressure).

T2-2-30

x The operation of forward/reverse switch (28) becomes invalid when the parking brake is applied. When the park brake is applied, it is not possible to engage transmission (13) and drive through the parking brake. x Armrest switch (47) is equipped when the optional stick steering is installed. This switch is turned OFF when the armrest is not lowered properly, causing the machine in the neutral status and engine does not start.

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-28

a-

Brake Pedal Position: Lightly applied

b-

OFF

c-

12345678911121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Monitor Monitor Controller Engine Control Module (ECM) Engine Downshift Switch (DSS) Hold Switch Transmission Torque Converter Oil Temperature Sensor

151617181920-

Engine Speed Sensor Main Controller (MC) (Sub) Machine Speed Sensor Lock Up Clutch Solenoid Valve Forward Clutch Solenoid Valve High Range Clutch Solenoid Valve Reverse Clutch Solenoid Valve Speed Shift Solenoid Valve Shift Up Switch Shift Down Switch Forward Position Neutral Position Reverse Position

28- Forward/Reverse Switch 29- Joystick Steering System Switch 30- Parking Brake Solenoid Valve 31- Pressure Sensor (Parking Brake) 32- Parking Brake Switch 33- Declutch Position Switch 34- Power Mode Selector Switch 35- Travel Mode Selector Switch 36- AUTO 2 Mode 37- Manual Mode 38- AUTO 1 Mode 39- Key Switch

21222324252627-

T2-2-31

Brake Pedal Position: Fully applied 40- Brake Pedal (Left) 41- Pressure Sensor (Brake Secondary Pressure) 42- Brake Pedal (Right) 43- Brake Pedal (Right) Switch 44- Lift Arm Angle Sensor 45- Pressure Sensor (Lift Arm Raise) 46- Pressure Sensor (Bucket Dump) 47- Armrest Switch

SECTION 2 SYSTEM Group 2 Control System Forward/Reverse Switch Activation Control Purpose: The forward/reverse switch activation control enables forward/reverse movement by operating forward/reverse switch (28) with joystick steering system switch (29) turned on.

Operation: 1. Forward/reverse switch (28), and joystick steering system switch (29), machine speed sensor (17), parking brake pressure sensor (31), and armrest switch (47) all send a signal to the Main Controller (MC) (Main) (3). When MC (Main) (3) receives these signals, it then responds with an output signal to the forward/reverse clutch solenoid valves (19, 21) of transmission (13).

2. When joystick steering system switch (29) is OFF, transmission (13) remains in neutral and machine does not move with forward/reverse switch (28).

3. When joystick steering system switch (29) has been turned ON while machine stops (machine speed: 0 km/h (0 mph), forward/reverse switch (28): neutral position (26)), MC (Main) (3) turns ON the indicator of joystick steering system switch (29), and will act on the next input from forward/reverse switch (28).

4. When starter key (39) is placed to ON position, transmission (13) returns to neutral condition.

MC (Main) (3) turns OFF the indicator of joystick steering system switch (29).

5. To use forward/reverse switch (28) again, turn the switch (28) OFF, and go back to step 3.

NOTE: In case forward/reverse switch (28) is defective, MC (Main) (3) sets transmission (13) in neutral and the machine cannot move.

T2-2-32

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-29

a-

Brake Pedal Position: Lightly applied

b-

OFF

c-

12345678911121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Monitor Monitor Controller Engine Control Module (ECM) Engine Downshift Switch (DSS) Hold Switch Transmission Torque Converter Oil Temperature Sensor

151617181920-

Engine Speed Sensor Main Controller (MC) (Sub) Machine Speed Sensor Lock Up Clutch Solenoid Valve Forward Clutch Solenoid Valve High Range Clutch Solenoid Valve Reverse Clutch Solenoid Valve Speed Shift Solenoid Valve Shift Up Switch Shift Down Switch Forward Position Neutral Position Reverse Position

28- Forward/Reverse Switch 29- Joystick Steering System Switch 30- Parking Brake Solenoid Valve 31- Pressure Sensor (Parking Brake) 32- Parking Brake Switch 33- Declutch Position Switch 34- Power Mode Selector Switch 35- Travel Mode Selector Switch 36- AUTO 2 Mode 37- Manual Mode 38- AUTO 1 Mode 39- Key Switch

21222324252627-

T2-2-33

Brake Pedal Position: Fully applied 40- Brake Pedal (Left) 41- Pressure Sensor (Brake Secondary Pressure) 42- Brake Pedal (Right) 43- Brake Pedal (Right) Switch 44- Lift Arm Angle Sensor 45- Pressure Sensor (Lift Arm Raise) 46- Pressure Sensor (Bucket Dump) 47- Armrest Switch

SECTION 2 SYSTEM Group 2 Control System Manual Speed Shift Control 6. MC (Main) (3) also limits the range selection when this would be damaging to the transmission.

Purpose: The manual speed shift control changes the selected transmission range manually.

7. MC (Main) (3) changes the downshifting ranges a step at a time so as not to damage transmission (13); i.e. from fourth to third, etc. These step by step shifts are done according to the machine speed.

Operation: 1. Main Controller (MC) (Main) (3) receives a signal to manually control the transmission from travel mode selector switch (35). (Refer to Automatic Speed Shift Control.)

8. This protects the transmission by reducing downshift shock loads.

9. When selected range is changed, MC (Main) (3) sends a signal to monitor controller (7) via CAN communication (5) to indicate on the monitor panel which transmission range is currently applied.

2. When Manual (37) is selected, second speed range is automatically set when key switch (39) is turned to ON. 3. MC (Main) (3) receives a signal from machine speed sensor (17), shift up switch (23) and shift down switch (24).

10. Monitor controller (7) displays the applied range on monitor panel (6).

4. The speed range signal from shift up switch (23) or shift down switch (24) is sent to MC (Main) (3) which responds with an output signal to speed range solenoid valve (22) of transmission (13) when travel mode selector switch (35) is on manual mode (37).

This changes the selected range of transmission (13) manually.

5. Pressing shift up switch (23) changes the shift range up by one from second to third, then to fourth.

Pressing shift down switch (24) downshifts by one in reverse order.

Speed Shift First Second Third Fourth

Engaged clutch First Second Third Second, High

T2-2-34

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-30

a-

Brake Pedal Position: Lightly applied

b-

OFF

c-

12345678911121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Monitor Monitor Controller Engine Control Module (ECM) Engine Downshift Switch (DSS) Hold Switch Transmission Torque Converter Oil Temperature Sensor

151617181920-

Engine Speed Sensor Main Controller (MC) (Sub) Machine Speed Sensor Lock Up Clutch Solenoid Valve Forward Clutch Solenoid Valve High Range Clutch Solenoid Valve Reverse Clutch Solenoid Valve Speed Shift Solenoid Valve Shift Up Switch Shift Down Switch Forward Position Neutral Position Reverse Position

28- Forward/Reverse Switch 29- Joystick Steering System Switch 30- Parking Brake Solenoid Valve 31- Pressure Sensor (Parking Brake) 32- Parking Brake Switch 33- Declutch Position Switch 34- Power Mode Selector Switch 35- Travel Mode Selector Switch 36- AUTO 2 Mode 37- Manual Mode 38- AUTO 1 Mode 39- Key Switch

21222324252627-

T2-2-35

Brake Pedal Position: Fully applied 40- Brake Pedal (Left) 41- Pressure Sensor (Brake Secondary Pressure) 42- Brake Pedal (Right) 43- Brake Pedal (Right) Switch 44- Lift Arm Angle Sensor 45- Pressure Sensor (Lift Arm Raise) 46- Pressure Sensor (Bucket Dump)

SECTION 2 SYSTEM Group 2 Control System Automatic Speed Shift Control Purpose: The automatic speed shift control changes the speed shift of transmission automatically. The shift change mode can be selected according to the work mode or work condition requirements. In addition, the timing of automatic speed shift is changed according to the power mode application to help with reducing fuel consumption and maintain the performance.

4. MC (Main) (3) adapts transmission (13) downshift selection to the operation parameters and permits transmission (13) downshift to occur in a step by step manner when the parameters will permit MC (Main) (3) to safely do so; for example, when downshifting transmission (13) from fourth to third, the machine speed must be in an acceptable range before MC (Main) (3) will permit the shift to occur, etc. If the selection is attempted to be made in such a way that the downshift could make operation unsafe or damage the machine, MC (Main) (3) will not permit the downshift to occur.

Operation: 1. Main Controller (MC) (Main) (3) receives an input signal from travel mode selector switch (35) and power mode selector switch (34).

5. Therefore, downshift shock loads are reduced, the shift is made smoothly and the transmission is protected.

2. MC (Main) (3) receives signals from machine speed sensor (17), shift up switch (23) and shift down switch (24), and judges the currently selected speed range.

6. MC (Main) (3) sends a speed range signal to monitor controller (7) via CAN communication (5) at the shift selection changes are taking place.

3. MC (Main) (3) sends the speed shift signal to speed shift solenoid valve (22) of transmission (13) in response to the input signal. Transmission (13) will automatically shift as required by the operating conditions.

7. Monitor controller (7) displays the current speed range on monitor panel (6).

NOTE: When travel mode selector switch (35) becomes Travel (Shift Change) Mode x AUTO 1 (38): The machine starts out in second range and shifts up to fourth range. When operating load is high, it will automatically downshift from second to first range. x AUTO 2 (36): The machine starts out in second range and shifts up to fourth range. When operating load is high, it will not automatically downshift to first speed range. x Manual (37): The speed range is selected manually. (Refer to Manual Speed Shift Control.)

malfunctions, MC (Main) (3) sets the driving shift change mode to manual mode.

NOTE: When machine speed sensor (17) and machine

Power Mode x OFF: The transmission shifts up to the next range more quickly than usual. This improves the rate of fuel consumption while operating the machine in low load conditions. x ON: The transmission shifts up to the next range less quickly than usual. This improves the operation of the machine while under high load conditions.

T2-2-36

speed sensor (backup) (19) becomes malfunctions, MC (Main) (3) sets the driving shift change mode to manual mode via backup control.

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-31

a-

Brake Pedal Position: Lightly applied

b-

OFF

c-

12345678911121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Monitor Monitor Controller Engine Control Module (ECM) Engine Downshift Switch (DSS) Hold Switch Transmission Torque Converter Oil Temperature Sensor

151617181920-

Engine Speed Sensor Main Controller (MC) (Sub) Machine Speed Sensor Lock Up Clutch Solenoid Valve Forward Clutch Solenoid Valve High Range Clutch Solenoid Valve Reverse Clutch Solenoid Valve Speed Shift Solenoid Valve Shift Up Switch Shift Down Switch Forward Position Neutral Position Reverse Position

28- Forward/Reverse Switch 29- Joystick Steering System Switch 30- Parking Brake Solenoid Valve 31- Pressure Sensor (Parking Brake) 32- Parking Brake Switch 33- Declutch Position Switch 34- Power Mode Selector Switch 35- Travel Mode Selector Switch 36- AUTO 2 Mode 37- Manual Mode 38- AUTO 1 Mode 39- Key Switch

21222324252627-

T2-2-37

Brake Pedal Position: Fully applied 40- Brake Pedal (Left) 41- Pressure Sensor (Brake Secondary Pressure) 42- Brake Pedal (Right) 43- Brake Pedal (Right) Switch 44- Lift Arm Angle Sensor 45- Pressure Sensor (Lift Arm Raise) 46- Pressure Sensor (Bucket Dump)

SECTION 2 SYSTEM Group 2 Control System Downshift Control 7. When any of the following conditions exists under the topic "Deactivation Conditions", the downshift control is deactivated.

Purpose: The downshift control permits transmission (13) to downshift to the next lower range when it is applied.

Operation: 1. Main Controller (MC) (Main) (3) receives the signals from machine speed sensor (17), driving mode selector switch (35), downshift switch (DSS) (11) and the currently applied range within transmission (13).

2. When downshift switch (11) is applied, MC (Main) (3) downshifts by one range when the machine speed reaches the target speed for downshift (as from 4 to 3, from 3 to 2, etc.). MC (Main) (3) sends the shift signal to solenoid valve (22) of transmission (13) to downshift the speed range to the next one.

Deactivation Conditions: x Forward/Reverse Switch (28): In use x Driving Mode Switch (35): In use x Hold Switch (12): Operated with the shift change mode set to AUTO 1 mode (38) or AUTO 2 mode (36)

NOTE: Downshift switch (11) is located on the joystick steering lever.

NOTE: When machine speed sensor (17) malfunctions,

3. With AUTO1 (38) or AUTO2 (36) shift change mode selected, when driving machine while holding downshift switch (11) depressed, MC (Main) (3) downshifts the speed range from fourth to third, then from third to second by one range automatically when the machine speed reaches the target speed, and holds the speed range in second until releasing downshift switch (11).

NOTE: When the lock-up clutch is used, pressing

downshift switch (11) disengages the lock-up clutch before downshifting the speed range .

4. By applying downshift switch (DSS) (11) within 2 seconds after releasing it, MC (Main) (3) changes downshifts the speed range from second to first when the machine speed reaches the target speed for downshift.

5. The downshift control is deactivated and is returned to automatic speed shift control in 2 seconds after the speed shift is lowered. (Refer to Automatic Speed Shift Control.)

6. With the Manual (37) shift change mode selected, MC (Main) (3) downshifts the speed range by applying downshift switch (DSS) (11) by one range when the machine speed reaches the target speed for downshift. The selected shift range is held after lowering to the next one down. Apply downshift switch (11) again to downshift to the next one down. (Refer to Manual Speed Shift Control.)

T2-2-38

MC (Main) (3) sets the driving shift change mode to manual mode via back up control.

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-32

a-

Brake Pedal Position: Lightly applied

b-

OFF

c-

12345678911121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Monitor Monitor Controller Engine Control Module (ECM) Engine Downshift Switch (DSS) Hold Switch Transmission Torque Converter Oil Temperature Sensor

151617181920-

Engine Speed Sensor Main Controller (MC) (Sub) Machine Speed Sensor Lock Up Clutch Solenoid Valve Forward Clutch Solenoid Valve High Range Clutch Solenoid Valve Reverse Clutch Solenoid Valve Speed Shift Solenoid Valve Shift Up Switch Shift Down Switch Forward Position Neutral Position Reverse Position

28- Forward/Reverse Switch 29- Joystick Steering System Switch 30- Parking Brake Solenoid Valve 31- Pressure Sensor (Parking Brake) 32- Parking Brake Switch 33- Declutch Position Switch 34- Power Mode Selector Switch 35- Travel Mode Selector Switch 36- AUTO 2 Mode 37- Manual Mode 38- AUTO 1 Mode 39- Key Switch

21222324252627-

T2-2-39

Brake Pedal Position: Fully applied 40- Brake Pedal (Left) 41- Pressure Sensor (Brake Secondary Pressure) 42- Brake Pedal (Right) 43- Brake Pedal (Right) Switch 44- Lift Arm Angle Sensor 45- Pressure Sensor (Lift Arm Raise) 46- Pressure Sensor (Bucket Dump)

SECTION 2 SYSTEM Group 2 Control System Speed Shift Delay Control Purpose: The transmission shift delay control holds back the upshift timing at automatic speed shift control. Therefore, this control maintains machine performance during bucket and lift arm movement while loading.

NOTE:

x Speed shift delay control is deactivated when power mode switch (34) or travel mode selector switch (35) is operated, or when parking brake switch (32) is ON. x The lock-up control takes priority over the shift change delay control. Therefore, even when the shift change delay mode is turned ON, shift up can be observed when the lock-up control should work.

Operation: 1. When the following items listed below under "Requirements" and "Any Satisfied Conditions" exist, the timing of shift up (2~3) is delayed at automatic speed shift control.

Requirements: x Forward/Reverse Switch (28): Forward Position (25) or Reverse Position (27) x Shift Change Mode Switch (35): AUTO 1 mode (38), AUTO 2 mode (36) x Speed Shift: Second or first x Parking Brake: Unlock x Machine Speed: Beyond the reference value below Power Mode OFF Direction

Engine speed (RPM)

Machine speed (km/h (mph))

Forward

-

10.2 (6.34)

800

9.4 (5.84)

1500

9.4 (5.84)

1850

11.4 (7.08)

Reverse

A C B

TNED-02-02-059

Power Mode ON

A-

Direction

Engine speed (RPM)

Machine speed (km/h (mph))

Forward

-

11.2 (6.96)

800

10.4 (6.46)

1500

10.4 (6.46)

1850

12.6 (7.83)

Reverse

B-

Any Satisfied Conditions: x Lift Arm Lower Operation (Lift Arm Angle Sensor (44)): Output Signal (Dumping, Loading Positions) x Pressure Sensor (Lift Arm Raise) (45): Output Signal (This signal is not seen as valid until a minimum of 3 seconds of application have past.) x Pressure Sensor (Bucket Dump) (46): Output Signal 2. Main Controller (MC) (Main) (3) delays the current speed shift signal for 8 seconds while in forward and 8 seconds while in reverse with the machine in motion.

3. Therefore, the upshift timing of speed-shift up (second to third) is delayed.

T2-2-40

Loading Position Setup Range of Lift Arm Rollback Position Setup Range of Lift Arm

C-

Horizontal Position of Lift Arm

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-33

a-

Brake Pedal Position: Lightly applied

b-

OFF

c-

12345678911121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Monitor Monitor Controller Engine Control Module (ECM) Engine Downshift Switch (DSS) Hold Switch Transmission Torque Converter Oil Temperature Sensor

151617181920-

Engine Speed Sensor Main Controller (MC) (Sub) Machine Speed Sensor Lock Up Clutch Solenoid Valve Forward Clutch Solenoid Valve High Range Clutch Solenoid Valve Reverse Clutch Solenoid Valve Speed Shift Solenoid Valve Shift Up Switch Shift Down Switch Forward Position Neutral Position Reverse Position

28- Forward/Reverse Switch 29- Joystick Steering System Switch 30- Parking Brake Solenoid Valve 31- Pressure Sensor (Parking Brake) 32- Parking Brake Switch 33- Declutch Position Switch 34- Power Mode Selector Switch 35- Travel Mode Selector Switch 36- AUTO 2 Mode 37- Manual Mode 38- AUTO 1 Mode 39- Key Switch

21222324252627-

T2-2-41

Brake Pedal Position: Fully applied 40- Brake Pedal (Left) 41- Pressure Sensor (Brake Secondary Pressure) 42- Brake Pedal (Right) 43- Brake Pedal (Right) Switch 44- Lift Arm Angle Sensor 45- Pressure Sensor (Lift Arm Raise) 46- Pressure Sensor (Bucket Dump)

SECTION 2 SYSTEM Group 2 Control System Declutch Control Purpose: The declutch control disengages the forward clutch by applying the brake pedal. With the drivetrain not drawing torque from the engine, the power can be concentrated on the loading circuit functions.

4. When all the items listed under "Deactivation Conditions" exist, MC (Main) (3) sends a signal to energize forward clutch solenoid valve (19) of transmission (13). In this state, the forward clutch is engaged.

Operation: 1. Main Controller (MC) (Main) (3) receives a signal from declutch position switch (33).

5. Monitor (6) displays the forward/reverse position with declutch cutoff control when the forward/ reverse clutches of transmission (13) are disengaged.

2. When all the items listed under "Conditions" exist, MC (Main) (3) stops energizing forward clutch solenoid valves (19) of transmission (13). In this state, neither forward/reverse clutches are engaged.

3. Consequently, the engine output power can be concentrated on the loading circuit functions.

Conditions: x Declutch Position Switch (33): (a) or (c) Position x Speed Range: Second or less x Machine speed: 20 km/h (12.5 mph) or less x Brake: Applied (Brake Pedal (Right) Switch (43): ON) x Pressure Sensor (Brake Second Pressure) (41): Below specified pressure x Forward/Reverse Switch (28): Forward (25) Declutch Position Brake Pedal (42) Lightly applied Speed Range: 0.63 MPa (91.4 First psi) or more Speed Range: 1.47 MPa (213.2 Second psi) or more

Brake Pedal (42) Fully applied 1.24 MPa (179.8 psi) or more 2.48 MPa (359.7 psi) or more

Deactivation Conditions: x Declutch Position Switch (33): OFF x Speed Range: Third speed or more x Brake: Released (Brake Pedal (Right) Switch (43): OFF) x Pressure Sensor (Brake Second Pressure) (41): Below specified pressure x Forward/Reverse Switch (28): Reverse (27) or Neutral (26) Declutch Position Speed Range: First Speed Range: Second

Brake Pedal (42) Brake Pedal (42) Lightly applied Fully applied Less than 0.37 MPa Less than 0.98 MPa (53.7 psi) (142.1 psi) Less than 1.21 MPa Less than 2.22 MPa (175.5 psi) (322.0 psi)

NOTE: When declutch position switch (33) and pressure

sensor (brake secondary pressure line) (41) malfunctions, the declutch control is deactivated.

T2-2-42

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-34

a-

Brake Pedal Position: Lightly applied

b-

OFF

c-

12345678911121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Monitor Monitor Controller Engine Control Module (ECM) Engine Downshift Switch (DSS) Hold Switch Transmission Torque Converter Oil Temperature Sensor

151617181920-

Engine Speed Sensor Main Controller (MC) (Sub) Machine Speed Sensor Lock Up Clutch Solenoid Valve Forward Clutch Solenoid Valve High Range Clutch Solenoid Valve Reverse Clutch Solenoid Valve Speed Shift Solenoid Valve Shift Up Switch Shift Down Switch Forward Position Neutral Position Reverse Position

28- Forward/Reverse Switch 29- Joystick Steering System Switch 30- Parking Brake Solenoid Valve 31- Pressure Sensor (Parking Brake) 32- Parking Brake Switch 33- Declutch Position Switch 34- Power Mode Selector Switch 35- Travel Mode Selector Switch 36- AUTO 2 Mode 37- Manual Mode 38- AUTO 1 Mode 39- Key Switch

21222324252627-

T2-2-43

Brake Pedal Position: Fully applied 40- Brake Pedal (Left) 41- Pressure Sensor (Brake Secondary Pressure) 42- Brake Pedal (Right) 43- Brake Pedal (Right) Switch 44- Lift Arm Angle Sensor 45- Pressure Sensor (Lift Arm Raise) 46- Pressure Sensor (Bucket Dump)

SECTION 2 SYSTEM Group 2 Control System Shift Holding Control Purpose: The shift holding control holds the current speed shift of transmission by operating the hold switch if necessary at automatic speed shift control.

Operation: 1. Main Controller (MC) (Main) (3) receives a signal from shift hold switch (12).

2. MC (Main) (3) keeps transmission (13) engaged in the current speed range after shift hold switch (12) has been applied once.

3. With the shift hold control applied, the engaged transmission (13) speed range is held in that range, despite accelerator pedal (1) and brake pedal (40, 42) position changes.

NOTE:

x Shift holding control deactivates the lock-up function, if activated, and holds the currently selected shift range. x The shift holding control is activated with AUTO 1 mode (38) or AUTO 2 mode (36) selected by shift change mode switch (35).

4. When all of the items in the following under "Deactivation Conditions" exist, MC (Main) (3) deactivates the shift hold control feature.

Deactivation Conditions: x Key Switch (39): OFF x Shift Hold Switch (12): Operated once more x Downshift Switch (11): Operated x Forward/Reverse Switch (28): Operated x Joystick Steering System Switch (29): ON x Shift Change Mode Switch (35): Operated x Parking Brake: Applied x Power Mode Selector Switch (34): Operated

T2-2-44

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-35

a-

Brake Pedal Position: Lightly applied

b-

OFF

c-

12345678911121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Monitor Monitor Controller Engine Control Module (ECM) Engine Downshift Switch (DSS) Hold Switch Transmission Torque Converter Oil Temperature Sensor

151617181920-

Engine Speed Sensor Main Controller (MC) (Sub) Machine Speed Sensor Lock Up Clutch Solenoid Valve Forward Clutch Solenoid Valve High Range Clutch Solenoid Valve Reverse Clutch Solenoid Valve Speed Shift Solenoid Valve Shift Up Switch Shift Down Switch Forward Position Neutral Position Reverse Position

28- Forward/Reverse Switch 29- Joystick Steering System Switch 30- Parking Brake Solenoid Valve 31- Pressure Sensor (Parking Brake) 32- Parking Brake Switch 33- Declutch Position Switch 34- Power Mode Selector Switch 35- Travel Mode Selector Switch 36- AUTO 2 Mode 37- Manual Mode 38- AUTO 1 Mode 39- Key Switch

21222324252627-

T2-2-45

Brake Pedal Position: Fully applied 40- Brake Pedal (Left) 41- Pressure Sensor (Brake Secondary Pressure) 42- Brake Pedal (Right) 43- Brake Pedal (Right) Switch 44- Lift Arm Angle Sensor 45- Pressure Sensor (Lift Arm Raise) 46- Pressure Sensor (Bucket Dump)

SECTION 2 SYSTEM Group 2 Control System Lock Up Control Purpose: The lock up control directly links the transmission to the engine when the Auto Shift Mode 1 or 2 is selected. This realizes efficient power transmission and helps to improve fuel efficiency and have higher ground speed.

Operation: 1. Main Controller (MC) (Main) (3) receives signals from power mode selector switch (34) and travel mode selector switch (35).

2. MC (Main) (3) also receives signals from machine speed sensor (17), shift switch (23), and brake secondary pressure sensor (41).

3. When the machine speed and conditions are satisfied, MC (Main) (3) activates the lock-up control to engage the lock-up clutch.

NOTE:

x The machine speed for the lock-up application differs according to the power mode setting. x While the lock-up clutch is used, the lock-up indicator "L-UP" is displayed on monitor (6).

4. When any of the items in the following under "Deactivation Conditions" exist, MC (Main) (3) deactivates the lock-up control feature.

Deactivation Conditions: x Auto Brake: Applied x Travel Mode Selector Switch (35): Manual x Machine speed is not suitable for the lock-up operation. x Forward/Reverse Switch (28): At Reverse (27) or Neutral (26) position, or Switched between Forward (25) and Reverse (27) x Speed Shift: First range, or Being changed to the lower range x Declutch Control: Activated x Shift Hold Switch (12): Pressed and shift range is being held x Downshift Switch (11): Pressed and shift range is being changed x Service Brake: Applied

NOTE: Use of the lock-up control is set via monitor (6)

using Setting Menu - Transmission Setting - Lockup. The lock-up function is turned ON (available) at shipment.

Refer to the Operation Manual.

T2-2-46

95Z7-01-04

SECTION 2 SYSTEM Group 2 Control System

115Z7-02-02-05

a-

Brake Pedal Position: Lightly applied

b-

OFF

c-

12345678911121314-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Monitor Monitor Controller Engine Control Module (ECM) Engine Downshift Switch (DSS) Hold Switch Transmission Torque Converter Oil Temperature Sensor

151617181920-

Engine Speed Sensor Main Controller (MC) (Sub) Machine Speed Sensor Lock Up Clutch Solenoid Valve Forward Clutch Solenoid Valve High Range Clutch Solenoid Valve Reverse Clutch Solenoid Valve Speed Shift Solenoid Valve Shift Up Switch Shift Down Switch Forward Position Neutral Position Reverse Position

28- Forward/Reverse Switch 29- Joystick Steering System Switch 30- Parking Brake Solenoid Valve 31- Pressure Sensor (Parking Brake) 32- Parking Brake Switch 33- Declutch Position Switch 34- Power Mode Selector Switch 35- Travel Mode Selector Switch 36- AUTO 2 Mode 37- Manual Mode 38- AUTO 1 Mode 39- Key Switch

21222324252627-

T2-2-47

Brake Pedal Position: Fully applied 40- Brake Pedal (Left) 41- Pressure Sensor (Brake Secondary Pressure) 42- Brake Pedal (Right) 43- Brake Pedal (Right) Switch 44- Lift Arm Angle Sensor 45- Pressure Sensor (Lift Arm Raise) 46- Pressure Sensor (Bucket Dump)

SECTION 2 SYSTEM Group 2 Control System Auto Brake Control Purpose: Auto brake automatically applies the service brake when the machine speed is too high or the traveling direction is switched over between forward and reverse at specified machine speed or more. This feature protects transmission by preventing overheated bearings or burnt clutches.

Direction Change Operation: 1. Main Controller (MC) (Main) (3) receives signals from machine speed sensor (17), forward/reverse switch (28), shift switch (23), and travel mode selector switch (35).

2. When the machine direction is changed while running over the specified speed (sensor reading value: 404 Hz), auto brake solenoid valve (40) is energized and magnetized.

Over Speeding Operation: 1. Main Controller (MC) (Main) (3) receives signals from machine speed sensor (17), forward/reverse switch (28), shift switch (23), and travel mode selector switch (35).

2. When machine speed sensor (17) sends the specified speed signal in each speed range (shown below) continuously for 100 msec or more, auto brake solenoid valve (40) is energized and magnetized.

Shift Speed Sensor Range Value (Hz) F1 1342 F2 1969 F2L 1477 F3 3222 F3L 2461 F4 (F4L) 3222

Shift Range R1 R2 R3

Speed Sensor Value (Hz) 1342 2148 3222

3. Transmission becomes neutral status, and lock-up solenoid (18) is turned OFF. 4. Auto brake indicator appears on the monitor.

NOTE: No alarm sounds.

5. When the machine speed decreases below 394 Hz, the selected direction (F or R) becomes effective to move the machine at safe speed.

6. When the machine speed decreases below 268 Hz, auto brake solenoid valve (40) is deenergized.

NOTE: Refer to page T2-4-14 Auto Brake System.

NOTE: Refer to the Operation Manual for the

corresponding machine speed on the speedometer.

3. Transmission becomes neutral status, and lock-up solenoid (18) is turned OFF. 4. Auto brake indicator appears on the monitor, and an alarm sounds.

5. When the machine speed decreases by 275 Hz or more continuously for 100 msec, auto brake solenoid valve (40) is deenergized.

T2-2-48

SECTION 2 SYSTEM Group 2 Control System

Pressurized oil

115Z7-02-02-06

123456789-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Monitor Monitor Controller Engine Control Module (ECM) Engine

1112131415161718-

Downshift Switch (DSS) Hold Switch Transmission Torque Converter Oil Temperature Sensor Engine Speed Sensor Main Controller (MC) (Sub) Machine Speed Sensor Lock Up Clutch Solenoid Valve

19- Forward Clutch Solenoid Valve 20- High Range Clutch Solenoid Valve 21- Reverse Clutch Solenoid Valve 22- Speed Shift Solenoid Valve 23- Shift Up Switch 24- Shift Down Switch 28- Forward/Reverse Switch 32- Parking Brake Switch

T2-2-49

35- Travel Mode Selector Switch 40- Auto Brake Solenoid Valve 41- Brake Valve

SECTION 2 SYSTEM Group 2 Control System (Blank)

T2-2-50

SECTION 2 SYSTEM Group 2 Control System Fan Control, Valve Control The fan control system and valve control consist of the following. x Fan Speed Control x Fan Reverse Rotation Control x Lift Arm and Bucket Selection Circuit Control x Exhaust Filter Manual Regeneration Control x Exhaust Filter Auto Regeneration Control x Ride Control (Option)

T2-2-51

SECTION 2 SYSTEM Group 2 Control System Fan Speed Control Purpose: The fan speed control optimizes the fan speed depending on engine speed, engine coolant temperature, intake air temperature, engine boost temperature, torque converter oil temperature, power mode setting, hydraulic oil temperature, HVAC refrigerant pressure, and HVAC settings.

Operation: 1. The following items provide inputs to Main Controller (MC) (Main) (1) from Engine Control Module (ECM) (9) via Controller Area Network (CAN) communication (3). x Engine speed signal x Coolant temperature sensor (14) signal x Intake air temperature sensor (13) signal x Engine boost temperature sensor (16) signal 2. The following items provide a sensor signal inputs to MC (Sub) (11). x Torque converter temperature sensor (41) signal x Power mode selector switch (35) signal x Hydraulic oil temperature sensor (37) signal x HVAC refrigerant pressure sensor (38) signal 3. MC (Sub) (11) optimizes the signal sent to fan speed control solenoid valve (31) as adjusted by the input signals shown in the above listed items.

T2-2-52

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-49

12345678910111213-

Main Controller (MC) (Man) Column Display Controller Controller Area Network (CAN) Air Conditioner Controller Outside Temperature Sensor Maintenance Pro Dr. (MPDr.) Monitor Monitor Controller Engine Control Module (ECM) Engine Main Controller (MC) (Sub) Engine Speed Sensor Intake Air Temperature Sensor

141516171920212223-

Coolant Temperature Sensor Transmission Boost Temperature Sensor Exhaust Temperature Sensor Forward Position Neutral Position Reverse Position Forward/Reverse Switch Joystick Steering System Switch 24- Parking Brake Solenoid Valve 25- Parking Brake Switch

26- Pressure Sensor (Parking Brake) 27- Fan Pump 28- Fan Motor 29- Fan Reversing Spool 30- Fan Reverse Rotation Control Solenoid Valve 31- Fan Speed Control Solenoid Valve 32- Hydraulic Fan Circuit Pressure Sensor 33- Fan Valve 34- Fan Reversing Switch

T2-2-53

35- Power Mode Switch 36- Key Switch 37- Hydraulic Oil Temperature Sensor 38- Pressure Sensor (Refrigerant Pressure) 39- Accelerator Pedal 40- Accelerator Pedal Sensor 41- Torque Converter Oil Temperature Sensor 42- Unloader Valve

SECTION 2 SYSTEM Group 2 Control System Fan Reverse Rotation Control Operation (MANUAL): 1. Main Controller (MC) (Sub) (11) receives a signal from fan reversing switch (34).

Purpose: The fan reverse rotation control reverses the rotation of the cooling fan from the normal rotation direction by operating the fan reversing switch (34).

2. MC (Sub) (11) activates fan reverse rotation control solenoid valve (30) and shifts fan reversing spool (29) when fan reversing switch (34) is set to manualreverse rotation position.

NOTE: As the cooling fan direction is reversed, dust that has lodged in the radiator and oil cooler is discharged, helping to clear the cooling elements of blockage.

3. MC (Main) (1) receives the signals from key switch (36) and pressure sensor (parking brake) (26).

Operation (AUTO): 1. Main Controller (MC) (Sub) (11) receives a signal from fan reversing switch (34).

4. MC (Sub) (11) holds the fan in reverse rotation until the key switch is turned OFF when fan manual reversing switch (34) is set to OFF with the parking brake applied.

2. MC (Sub) (11) activates fan reverse rotation control solenoid valve (30) and shifts fan reversing spool (29) when fan reversing switch (34) is set to autoreverse rotation position.

5. MC (Sub) (11) rotates the fan motor in the normal direction after the fan has rotated in reverse rotation for one minute with the parking brake released.

3. Therefore, fan motor (28) rotates in reverse.

4. MC (Sub) (11) activates fan speed control solenoid valve (31) at the same time and fixes the fan rotation speed at 1500 min-1 (specified value).

NOTE: The fan automatic reverse rotation can be set

5. After setting fan reversing switch (34) to autoreverse position, the fan rotates in normal direction for 10 minutes, then in reverse direction for 1 minute. After that, repeats Normal rotation (30 minutes) J Reverse rotation (1 minute) J Normal rotation (30 minutes). (This is the default setting at shipment.) The fan reverse rotation interval is 90 seconds when outside temperature is low.

with MPDr. (6).

NOTE: When the cooling fan rotation is changed, it

6. The fan speed control now optimizes the fan rotation speed depending on engine speed, engine coolant temperature, etc. (Refer to Fan Speed Control.)

7. When the fan reverse rotation control is deactivated by setting fan reversing switch (34) to OFF position, etc. the fan rotates only in normal direction until the fan reverse rotation control is activated again.

T2-2-54

reverses the direction of air flow; what was the outlet side is now the inlet side, and what was the inlet side is now the outlet side.

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-50

12345678910111213-

Main Controller (MC) (Man) Column Display Controller Controller Area Network (CAN) Air Conditioner Controller Outside Temperature Sensor Maintenance Pro Dr. (MPDr.) Monitor Monitor Controller Engine Control Module (ECM) Engine Main Controller (MC) (Sub) Engine Speed Sensor Intake Air Temperature Sensor

141516171920212223-

Coolant Temperature Sensor Transmission Boost Temperature Sensor Exhaust Temperature Sensor Forward Position Neutral Position Reverse Position Forward/Reverse Switch Joystick Steering System Switch 24- Parking Brake Solenoid Valve 25- Parking Brake Switch

26- Pressure Sensor (Parking Brake) 27- Fan Pump 28- Fan Motor 29- Fan Reversing Spool 30- Fan Reverse Rotation Control Solenoid Valve 31- Fan Speed Control Solenoid Valve 32- Hydraulic Fan Circuit Pressure Sensor 33- Fan Valve 34- Fan Reversing Switch

T2-2-55

35- Power Mode Switch 36- Key Switch 37- Hydraulic Oil Temperature Sensor 38- Pressure Sensor (Refrigerant Pressure) 39- Accelerator Pedal 40- Accelerator Pedal Sensor 41- Torque Converter Oil Temperature Sensor 42- Unloader Valve

SECTION 2 SYSTEM Group 2 Control System Lift Arm and Bucket Selection Circuit Control Purpose: The lift arm and bucket selection circuit control prioritizes hydraulic oil pressure and flow so as to improve machine efficiency when operating the machine. This depends on the lift arm position.

Operation: 1. Machine Controller (MC) (Sub) (5) receives signals from lift arm angle sensor (1), pressure sensor (lift arm) (2), pressure sensor (bucket roll back) (3), and pressure sensor (bucket dump) (4).

2. Pressurized oil from main pump (27) is supplied to lift arm cylinder (8) and bucket cylinder (10) through the bucket and lift arm parallel circuit (combined operation of both circuits) within multiple control valve (7). This operates both the lift arm raise and bucket circuits.

3. When item under the topic "Conditions" below exists, MC (Sub) (5) energizes and operates parallel/ tandem switching solenoid valve unit (6).

4. Pressurized oil from parallel/tandem switching solenoid valve unit (6) shifts lift arm flow rate control spool (12) (located inside control valve (7)) to the right.

5. Therefore, pressurized oil from main pump (27) is supplied to bucket cylinder (10) and increases the bucket force.

Conditions: x Combined operation of lift arm raised and bucket dumped with the lift arm set above horizontal position

NOTE: Refer to page T2-4-38 "Parallel Circuit Flow Rate Control" for the entire system circuit operation.

T2-2-56

SECTION 2 SYSTEM Group 2 Control System When deactivated (Parallel):

When operated (Tandem):

95TNED-02-02-51 123-

Lift Arm Angle Sensor Pressure Sensor (Lift Arm Raise) Pressure Sensor (Bucket Roll Back)

456-

Pressure Sensor (Bucket Dump) Main Controller (MC) (Sub) Parallel/Tandem Switching Solenoid Valve Unit

7891011-

T2-2-57

Multiple Control Valve Lift Arm Cylinder Lift Arm Spool Bucket Cylinder Bucket Spool

1213142728-

Selector Valve Parallel Circuit Tandem Circuit Main Pump Combination Valve

SECTION 2 SYSTEM Group 2 Control System Exhaust Filter Manual Regeneration Control 6. When any of the items under the topic "Deactivation Conditions" exists, or any of the topic "Conditions" is not satisfied, MC (Main) (1) deactivates the exhaust filter manual regeneration control and regeneration will not occur. When the engine is too cool to clean the exhaust filter manually, ECM (9) holds the minimum engine RPM's to specified value (1000 RPM's (min-1)) so the engine will warm up quickly.

Purpose: The exhaust filter manual regeneration control cleans the exhaust filter manually. The operator performs this by turning the exhaust filter cleaning switch (13) ON. Since this process requires engine heat, the engine is heated by means of a hydraulic restriction being imposed on the pump. This increases the engine workload temperature resulting in higher heat at the exhaust filter and the filter cleaning is activated.

Deactivation Conditions: x Coolant Temperature (14): 72 °C (220 °F) or higher x Exhaust Temperature (16): 528 °C (982 °F) or higher x Hydraulic Oil Temperature (17): 85 °C (185 °F) or higher

Operation: 1. Main Controller (MC) (Main) (1) receives a signal to clean (regenerate) exhaust filter from Engine Control Module (ECM) (9) via Controller Area Network (CAN) communication (3).

2. When all following items under the topic of "Conditions" exist, MC (Main) (1) activates solenoid valve (29) (SV2) by pressing exhaust filter switch (13).

Conditions: x Accelerator Pedal (35) Position: Not applied x Parking Brake (25): In Operation x Forward/Reverse Switch (22): Neutral Position (20) x Front Control Lever Lock: In Operation (Pressure Sensor (Primary Pilot Pressure) (28): Below specified value) 3. Solenoid valve (29) (SV2) delivers pilot oil pressure to bleed-off compensation spool (33) in multiple control valve (32) via the Pls port.

4. Bleed-off compensation spool (33) blocks the pilot circuit, and the pressure increases to 31.4 MPa (320 kgf/cm2, 4554 psi), which is the Main Relief valve (34) (MR) set pressure.

5. ECM (9) increases and holds the engine speed to 1000 RPM's (min-1), raising the exhaust temperature to burn the soot in the exhaust filter.

T2-2-58

SECTION 2 SYSTEM Group 2 Control System

SV2

MR

Pump

115TNED-02-02-52

12345678910111213-

Main Controller (MC) (Man) Column Display Controller Controller Area Network (CAN) Air Conditioner Controller Outside Temperature Sensor Maintenance Pro Dr. (MPDr.) Monitor Monitor Controller Engine Control Module (ECM) Engine Main Controller (MC) (Sub) Engine Speed Sensor Exhaust Filter Switch

1415161719202122232425-

Coolant Temperature Sensor Transmission Exhaust Temperature Sensor Hydraulic Oil Temperature Sensor Forward Position Neutral Position Reverse Position Forward/Reverse Switch Joystick Steering System Switch Parking Brake Solenoid Valve Parking Brake Switch

26- Pressure Sensor (Parking Brake) 27- Accessory Pump 28- Pressure Sensor (Primary Pilot Pressure) 29- Solenoid Valve (for DPF Regen) (SV2) 30- Torque Control Solenoid Valve 31- Pump Delivery Pressure Sensor 32- Multiple Control Valve 33- Bleed-off Compensation Spool 34- Main Relief Valve (MR) 35- Accelerator Pedal

T2-2-59

36- Accelerator Pedal Sensor

SECTION 2 SYSTEM Group 2 Control System Exhaust Filter Auto Regeneration Control 6. When any of the items under the "Deactivation Conditions" exists, or any of the topic "Conditions" is not satisfied, MC (Main) (1) deactivates the exhaust filter auto regeneration control and stops imposing restriction on the pump. When the engine is too cool to clean the exhaust filter automatically, ECM (9) holds the minimum engine speed to specified value (1000 RPM's (min-1)) so the engine will warm up quickly.

Purpose: The exhaust filter auto regeneration control regenerates (cleans) the exhaust filter automatically. Since this process requires engine heat, the engine is heated by means of a hydraulic restriction being imposed on the pump. This increases the engine workload temperature resulting in higher heat at the exhaust filter and the filter cleaning is activated.

Operation: 1. Main Controller (MC) (Main) (1) receives a signal to clean (regenerate) the exhaust filter from Engine Control Module (ECM) (9) via Controller Area Network (CAN) communication (3).

Deactivation Conditions: x Coolant Temperature (14): 72 °C (220 °F) or higher x Exhaust Temperature (16): 528 °C (982 °F) or higher x Hydraulic Oil Temperature (17): 85 °C (185 °F) or higher

2. When all the items under the topic of "Conditions" exist, MC (Main) (1) activates solenoid valve (29) (SV2).

3. Solenoid valve (29) (SV2) delivers pilot oil pressure to bleed-off compensation spool (33) in multiple control valve (32) via the Pls port.

4. Bleed-off compensation spool (33) blocks the pilot circuit, and the pressure increases to 31.4 MPa (320 kgf/cm2, 4554 psi), which is the Main Relief valve (34) (MR) set pressure.

5. ECM (9) increases the engine speed to 1000 RPM's (min-1), raising the exhaust temperature to burn the soot in the exhaust filter.

Conditions: x Accelerator Pedal (35) Position: Not applied x Parking Brake (25): In Operation x Forward/Reverse Switch (22): Neutral Position (20) x Front Control Lever Lock: In Operation (Pressure Sensor (Primary Pilot Pressure) (28): Below specified pressure)

T2-2-60

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-52a

12345678910111213-

Main Controller (MC) (Man) Column Display Controller Controller Area Network (CAN) Air Conditioner Controller Outside Temperature Sensor Maintenance Pro Dr. (MPDr.) Monitor Monitor Controller Engine Control Module (ECM) Engine Main Controller (MC) (Sub) Engine Speed Sensor Exhaust Filter Switch

1415161719202122232425-

Coolant Temperature Sensor Transmission Exhaust Temperature Sensor Hydraulic Oil Temperature Sensor Forward Position Neutral Position Reverse Position Forward/Reverse Switch Joystick Steering System Switch Parking Brake Solenoid Valve Parking Brake Switch

26- Pressure Sensor (Parking Brake) 27- Accessory Pump 28- Pressure Sensor (Primary Pilot Pressure) 29- Solenoid Valve (for DPF Regen) (SV2) 30- Torque Control Solenoid Valve 31- Pump Delivery Pressure Sensor 32- Multiple Control Valve 33- Bleed-off Compensation Spool 34- Main Relief Valve (MR) 35- Accelerator Pedal

T2-2-61

36- Accelerator Pedal Sensor

SECTION 2 SYSTEM Group 2 Control System Ride Control (Option) Purpose: The ride control reduces the fore and aft pitching that normally occurs while moving a wheel loader over uneven terrain by organizing a damper circuit in the lift arm (boom) cylinder. This is helpful to reduce operator discomfort and material spillage from the bucket.

6. MC (Sub) (10) deactivates the ride control when machine speed falls below the point of ride control engagement. When all of the items shown below under the topic of "Temporary Deactivation Conditions" exist, MC (Sub) (10) deactivates the ride control system to temporarily cease to operate.

Temporary Deactivation Conditions: x Lift Arm Raise Operation (Pressure Sensor (Lift Arm Raise) (17)): Beyond specified pressure (Reference: 0.41 MPa, 4.1 kgf/cm2, 60 psi or more) x Pump Delivery Pressure Sensor (13): Beyond specified pressure (Reference: 18 MPa, 184 kgf/cm2, 2611 psi or more)

Operation: 1. Main Controller MC (Main) (1) receives a machine speed signal from machine speed sensor (12).

2. MC (Sub) (10) receives a signal from ride control switch (15). MC (Main) (1) monitors the machine speed when ride control is in the AUTO mode or is ON.

7. MC (Main) (1) alerts monitor controller (5) of the ride control operation status via CAN communication (3) as the changes are happening.

NOTE: When the ride control is set to "Always ON", MC

(Main) (1) will not monitor the machine speed after energizing the ride control selector valve (14) (SV1) first time after starting the engine.

8. Monitor controller (5) displays the ride control state on monitor (4).

3. MC (Sub) (10) energizes ride control selector valve coil (14) (SV1) in multiple control valve (18) and ride control proportional solenoid valve (23) (SV2) when the machine reaches the speed to turn on ride control, and permits pilot oil to shift ride control spool (19).

NOTE: The speed at which ride control engages and

disengages can be adjusted with monitor (4) and MPDr. (22). The setting range can be adjusted between 3 km/h (1.9 mph) and 10 km/h (6.2 mph).

NOTE: When the following parts become defective, the

4. When this occurs, a damper circuit is organized between the rod side and bottom side of lift arm cylinder (21) by directing oil to designated circuits.

5. The damper circuit absorbs and dissipates the fore and aft pitching energy caused from the up and down movement of the lift arms while running over uneven terrain. The rod end of lift arm cylinder (21) will open to the tank circuit so that there is minimal latent vacuum at the rod side of the circuit. The base end of lift arm cylinder (21) opens to work against accumulator (20) to absorbs the fore and aft pitching shock cycles.

T2-2-62

ride control is deactivated. x Machine Speed Sensor (12) x Lift Arm Angle Sensor (16) x Pump Delivery Pressure Sensor (13)

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-41

1234567-

Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Monitor Monitor Controller Engine Control Module (ECM) Engine

8910111213-

Engine Revolution Sensor Coolant Temperature Sensor Main Controller (MC) (Sub) Transmission Machine Speed Sensor Pump Delivery Pressure Sensor

14- Ride Control Selector Valve (SV1) 15- Ride Control Switch 16- Lift Arm (Boom) Angle Sensor 17- Pressure Sensor (Lift Arm (Boom) Raise) 18- Multiple Control Valve

T2-2-63

1920212223-

Ride Control Spool Accumulator Lift Arm (Boom) Cylinder Maintenance Pro Dr. (MPDr.) Ride Control Proportional Solenoid Valve (SV2)

SECTION 2 SYSTEM Group 2 Control System (Blank)

T2-2-64

SECTION 2 SYSTEM Group 2 Control System Other Controls The other controls consist of the followings. x Transmission Alarm Control x Parking Brake Operation Indicator Control x Brake Low Oil Pressure Indicator Control x Low Steering Oil Pressure Indicator Control x Lift Arm Auto Leveler Height Kickout Control x Lift Arm Auto Leveler Lower Kickout Control x Quick Power Mode Control x Auto Idling Stop Control x Secondary Steering Control (Option)

T2-2-65

SECTION 2 SYSTEM Group 2 Control System Transmission Alarm Control Purpose: The transmission alarm control lights the transmission warning indicator of the column display controller for protection of the transmission when the transmission becomes abnormal.

Operation: 1. When any of the following abnormalities with the transmission are detected, Main Controller (MC) (Main) (1) sends the signal to column display controller (2) via Controller Area Network (CAN) (30). x Abnormal machine speed sensor (T/M output revolution sensor) (13) x Abnormal engine speed backup sensor (Engine revolution sensor) x Abnormal T/M control valve solenoid valves x Simultaneous input of F and R from forward/reverse switch (15) 2. Column display controller (2) lights transmission warning indicator (26).

T2-2-66

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-36

12345678910-

Main Controller (MC) (Main) Column Display Controller Air Conditioner Controller Monitor Monitor Controller Engine Control Module (ECM) Engine Main Controller (MC) (Sub) Transmission Engine Speed Sensor

1213151617-

Parking Brake Switch Machine Speed Sensor Forward/Reverse Switch Parking Brake Solenoid Valve Pressure Sensor (Parking Brake) 18- Pressure Sensor (Brake Primary Pressure) (Front) 19- Pressure Sensor (Brake Primary Pressure) (Rear)

20- Steering Pressure Switch 21- Brake Pedal (Left) 22- Pressure Sensor (Brake Secondary Pressure) 23- Brake Pedal (Right) 24- Brake Pedal (Right) Switch 25- Alarm 26- Transmission Warning Indicator 27- Parking Brake Indicator

T2-2-67

28- Low Brake Oil Pressure Indicator 29- Low Steering Oil Pressure Indicator 30- Controller Area Network (CAN)

SECTION 2 SYSTEM Group 2 Control System Parking Brake Operation Indicator Control Purpose: The parking brake operation indicator control illuminates the parking brake indicator on the monitor control panel when the parking brake is applied.

Operation: 1. When the parking brake is applied while parking the machine, Main Controller (MC) (1) receives a signal from pressure sensor (parking brake) (17).

2. Parking brake switch (18) ON signal energizes parking brake solenoid valve (16) that permits the pressurized oil in parking brake (31) to the hydraulic tank. Parking brake (31) is applied with spring force, securing the machine in position.

3. When the pressure inside parking brake actuator (31) circuit is below the specified level (1.7 MPa, 17 kgf/cm2, 247 psi or less) that would release parking brake actuator (31), pressure sensor (17) indicates this pressure via a signal that is sent to MC (1). MC (1) confirms that the park brake is applied via a signal sent to column display controller (2).

4. Column display controller (2) lights illuminates parking brake indicator (27).

5. Parking brake switch OFF signal de-energizes parking brake solenoid valve (16) as it has opened the circuit from 24 VDC to the parking brake coil.

This permits the pressurized oil to move from the pilot pump to parking brake actuator (31). With pressurized oil applied, the parking brake actuator (31) pushes the piston against the spring to release the parking brake.

6. When the pressure inside parking brake (31) circuit is above 2.0 MPa, 20 kgf/cm2, 290 psi) a signal is sent from pressure sensor (17). MC (1) confirms that the park brake is released and sends the OFF signal to column display controller (2).

7. Column display controller (2) turns OFF parking brake indicator (27).

T2-2-68

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-37

12345678910-

Main Controller (MC) (Main) Column Display Controller Air Conditioner Controller Monitor Monitor Controller Engine Control Module (ECM) Engine Main Controller (MC) (Sub) Transmission Engine Speed Sensor

1213151617-

Parking Brake Switch Machine Speed Sensor Forward/Reverse Switch Parking Brake Solenoid Valve Pressure Sensor (Parking Brake) 18- Pressure Sensor (Brake Primary Pressure) (Front) 19- Pressure Sensor (Brake Primary Pressure) (Rear)

20- Steering Pressure Switch 21- Brake Pedal (Left) 22- Pressure Sensor (Brake Secondary Pressure) 23- Brake Pedal (Right) 24- Brake Pedal (Right) Switch 25- Alarm 26- Transmission Warning Indicator 27- Parking Brake Indicator

T2-2-69

28- Low Brake Oil Pressure Indicator 29- Low Steering Oil Pressure Indicator 30- Controller Area Network (CAN)

SECTION 2 SYSTEM Group 2 Control System Low Brake Oil Pressure Indicator Control Purpose: Main Controller (MC) (1) sends a signal to column display controller (2) to illuminate the low oil brake pressure indicator on the monitor control panel when the service brake pressure circuit falls below a safe level.

Operation: 1. When the service brake pressure circuit is below 3.9 MPa (40 kgf/cm2, 566 psi or less), either at front service brake primary pressure sensor (18) or rear service brake primary pressure sensor (19), MC (Sub) (8) sends OFF signal to column display controller (2) in 0.8 seconds.

2. Column display controller (2) illuminates low brake oil pressure indicator (28).

3. When the service brake pressure circuit is well above 4.4 MPa (44.9 kgf/cm2, 638 psi or more) either at front service brake primary pressure sensor (18) or rear service brake primary pressure sensor (19), MC (Sub) (8) sends ON signal to column display controller (2).

4. Column display controller (2) turns OFF low brake oil pressure indicator (28).

NOTE: When either at front service brake primary

pressure sensor (18) or rear service brake primary pressure sensor (19) malfunctions, low brake oil pressure indicator (28) illuminates and remains ON.

T2-2-70

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-38

12345678910-

Main Controller (MC) (Main) Column Display Controller Air Conditioner Controller Monitor Monitor Controller Engine Control Module (ECM) Engine Main Controller (MC) (Sub) Transmission Engine Speed Sensor

1213151617-

Parking Brake Switch Machine Speed Sensor Forward/Reverse Switch Parking Brake Solenoid Valve Pressure Sensor (Parking Brake) 18- Pressure Sensor (Brake Primary Pressure) (Front) 19- Pressure Sensor (Brake Primary Pressure) (Rear)

20- Steering Pressure Switch 21- Brake Pedal (Left) 22- Pressure Sensor (Brake Secondary Pressure) 23- Brake Pedal (Right) 24- Brake Pedal (Right) Switch 25- Alarm 27- Parking Brake Indicator 28- Low Brake Oil Pressure Indicator

T2-2-71

29- Low Steering Oil Pressure Indicator 30- Controller Area Network (CAN)

SECTION 2 SYSTEM Group 2 Control System Low Steering Oil Pressure Indicator Control (Option) Purpose: The low steering oil pressure indicator control illuminates the steering indicator on the monitor control panel when steering oil pressure is below the specified value.

Operation: 1. When steering oil pressure is below the secondary steering response level threshold and triggers steering pressure switch (20): to open the circuit between the switch and Main Controller (MC) (Sub) (8), MC (Sub) (8) sends the OFF signal to column display controller (2).

2. Column display controller (2) illuminates low steering oil pressure indicator (29).

3. MC (Sub) (8) also engages the secondary steering system (optional), if equipped, as determined by operating conditions. (Refer to Secondary Steering Control.)

4. When steering oil pressure is above the specified level, steering pressure switch (20) closes (turns ON), providing this input to MC (Sub) (8). Then, MC (Sub) (8) sends ON signal to column display controller (2).

5. Column display controller (2) turns OFF low steering oil pressure indicator (29).

NOTE: Steering pressure switch (20) is not equipped without the secondary steering system option. This control does not exist and low steering oil pressure indicator (29) keeps OFF.

T2-2-72

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-39

12345678910-

Main Controller (MC) (Main) Column Display Controller Air Conditioner Controller Monitor Monitor Controller Engine Control Module (ECM) Engine Main Controller (MC) (Sub) Transmission Engine Speed Sensor

1213151617-

Parking Brake Switch Machine Speed Sensor Forward/Reverse Switch Parking Brake Solenoid Valve Pressure Sensor (Parking Brake) 18- Pressure Sensor (Brake Primary Pressure) (Front) 19- Pressure Sensor (Brake Primary Pressure) (Rear)

20- Steering Pressure Switch 21- Brake Pedal (Left) 22- Pressure Sensor (Brake Secondary Pressure) 23- Brake Pedal (Right) 24- Brake Pedal (Right) Switch 25- Alarm 27- Parking Brake Indicator 28- Low Brake Oil Pressure Indicator

T2-2-73

29- Low Steering Oil Pressure Indicator 30- Controller Area Network (CAN)

SECTION 2 SYSTEM Group 2 Control System Lift Arm (Boom) Auto Leveler Height Kickout Control 6. MC (Sub) (1) determines the stopping position of the lift arm (pre-selected by the operator), and MC (Sub) (1) deenergizes lift arm lowering detent coil (7) on pilot valve (5).

Purpose: The lift arm height kickout control stops the lift arm as it is raising. It stops at any position - between where the lift arms are horizontal and fully raised - that has been preset by the operator.

IMPORTANT: After replacing the lift arm angle sensor, Main Controller (MC) (Main), or Main Controller (MC) (Sub), perform learning control of lift arm angle sensor (12) prior to performing work. (Refer to SECTION 4 OPERATIONAL PERFORMANCE TEST.)

7. Pilot pressure oil from loader pilot valve (5) shifts lift arm spool (9) of multiple control valve (8) to the neutral position from what was previously the raise position. Then, the lift arm stops.

NOTE: When lift arm angle sensor (12) malfunctions, the lift arm auto leveler height kickout control will no longer function.

A

Operation: 1. The lift arm height kickout control position is able to be viewed on the setting screen of dual lift arm auto leveler - height kickout, which is memorized in MC (Sub) (1).

C

2. Adjust the lift arm height kickout control to the required level and select the height kickout ON to make this feature effective.

B

3. MC (Sub) (1) receives a signal from lift arm angle sensor (12).

4. MC (Sub) (1) energizes lift arm raising coil (6) of pilot valve (5) as the lift arm is raised/and the detent function is applied at the control lever.

Pilot pressure oil is directed to lift arm spool (9) of multiple control valve (8) to put it into the raise position and it holds it in this state.

TNED-02-02-042 AB-

5. Pressurized oil from the main pump is supplied to the bottom end of lift arm cylinder (10) and the lift arm continues to rise.

T2-2-74

Full Height Position of Lift Arm Horizontal Position of Lift Arm

C-

Setting Range of Lift Arm Stop (For Loading Range)

SECTION 2 SYSTEM Group 2 Control System

95TNED-02-02-44

123-

Main Controller (MC) (Sub) Monitor Monitor Controller

456-

Controller Area Network (CAN) Pilot Valve Lift Arm Raising Coil

789-

T2-2-75

Lift Arm Lowering Coil Multiple Control Valve Lift Arm Spool

10- Lift Arm Cylinder 11- Bucket Cylinder 12- Lift Arm Angle Sensor

SECTION 2 SYSTEM Group 2 Control System Lift Arm (Boom) Auto Leveler Lower Kickout Control Purpose: The lift arm lower kickout control stops the lift arm as it is lowering. It stops at any position - between where the lift arms are horizontal and fully lowered - that has been preset by the operator.

6. MC (Sub) (1) determines the stopping position of the lift arm (pre-selected by the operator), and MC (Sub) (1) deenergizes lift arm raising detent coil (6) on pilot valve (5).

IMPORTANT: After replacing the lift arm angle sensor, Main Controller (MC) (Main), or Main Controller (MC) (Sub), perform learning control of lift arm angle sensor (12) prior to performing work. (Refer to SECTION 4 OPERATIONAL PERFORMANCE TEST.) Operation: 1. The lift arm lower kickout control position is able to be viewed on the setting screen of dual lift arm auto leveler - lower kickout, which is memorized in MC (Sub) (1).

7. Pilot pressure oil from loader pilot valve (5) shifts lift arm spool (9) of multiple control valve (8) to the neutral position from what was previously the lower position. Then, the lift arm stops.

NOTE: When lift arm angle sensor (12) malfunctions, the lift arm auto leveler lower kickout control will no longer function.

2. Adjust the lift arm lower kickout control to the required level and select the lower kickout ON to make this feature effective.

B

3. MC (Sub) (1) receives a signal from lift arm angle sensor (12).

C

4. MC (Sub) (1) energizes lift arm lowering coil (7) of pilot valve (5) as the lift arm is lowered/and the detent function is applied at the control lever.

Pilot pressure oil is directed to lift arm spool (9) of multiple control valve (8) to put it into the lower position and it holds it in this state.

A TNED-02-02-043

5. Pressurized oil from the main pump is supplied to the rod end of lift arm cylinder (10) and the lift arm continues to lower.

AB-

T2-2-76

Lowered Position of Lift Arm Horizontal Position of Lift Arm

C-

Setting Range of Lift Arm Stop (For Return To Dig Position)

SECTION 2 SYSTEM Group 2 Control System

95TNED-02-02-45

123-

Main Controller (MC) (Sub) Monitor Monitor Controller

456-

Controller Area Network (CAN) Pilot Valve Lift Arm Raising Coil

789-

T2-2-77

Lift Arm Lowering Coil Multiple Control Valve Lift Arm Spool

10- Lift Arm Cylinder 11- Bucket Cylinder 12- Lift Arm Angle Sensor

SECTION 2 SYSTEM Group 2 Control System Quick Power Mode Control Purpose: Applying the quick P (power) mode switch temporarily changes the work mode to the power mode for greater power with the power mode switch OFF. This provides better digging power and greater breakout force.

Operation: 1. Main Controller (MC) (Main) (3) receives signals from power mode selector switch (35) and quick P (power) switch (41).

2. When MC (Main) (3) receives input signal from quick P switch (41), the power mode is activated.

3. The power mode remains activated until the quick P switch (41) is released. (Quick P mode applies the normal Power mode function.)

4. When any of the following items listed under the topic below of "Deactivation Conditions" exists, MC (Main) (3) deactivates the quick P mode control.

Deactivation Conditions: x Quick Power Switch (41): Pushed once more x Speed-shift up during automatic speed shift x Selected speed shift and torque converter rotation speed ratio: Specified value (Reference: 0.8) or more x Forward/Reverse Switch (27): Operated or Neutral Position (25) x Power Mode Selector Switch (35): Changed 5. MC (Main) (3) sends the power mode status signal to monitor controller (9) via CAN communication (5) as the changes are happening.

6. Monitor controller (9) displays the power mode status on monitor (8).

T2-2-78

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-48

1234567891011-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Air Conditioner Controller Maintenance Pro Dr. (MPDr.) Monitor Monitor Controller Engine Control Module (ECM) Engine

1213141516192122232425-

Exhaust Temperature Sensor Engine Speed Sensor (Backup) Main Controller (MC) (Sub) Coolant Temperature Sensor Transmission Engine Speed Sensor Machine Speed Sensor Shift Up Switch Shift Down Switch Forward Position Neutral Position

26- Reverse Position 27- Forward/Reverse Switch 28- Joystick Steering System Switch 29- Pump Delivery Pressure Sensor 30- Torque Control Solenoid Valve 31- Parking Brake Solenoid Valve 32- Pressure Sensor (Parking Brake) 33- Parking Brake Switch 35- Power Mode Selector Switch

T2-2-79

363738394041-

Travel Mode Selector Switch AUTO 2 Mode Manual Mode AUTO 1 Mode Starter Key Switch Quick Power Switch

SECTION 2 SYSTEM Group 2 Control System Auto Idling Stop Control Purpose: The auto idling stop control automatically stops the engine to reduce fuel consumption when the machine is not operated within a fixed time frame.

NOTE: The auto idling stop control can be adjusted or turned ON/OFF with monitor (8) and MPDr. (7).

NOTE: After it shuts down, return the key switch to the

Operation: 1. When all of the following items under the topic of "Conditions" exist, MC (3) sends the auto idling stop signal to monitor controller (9) via Controller Area Network (CAN) communication (5).

2. Monitor controller (9) displays the auto idling stop notice on monitor (8) and column display controller (4) sounds buzzer (48) via CAN communication (5) once 30 seconds before the auto idling stop engages. The time for auto idling stop is adjustable by settings within monitor (8). Column display controller (4) sounds buzzer (48) with an intermittent sound at 15 seconds and another sound at 5 seconds to alert the operator of engine shut down.

3. MC (3) turns ON auto idling stop relay (43) when the auto idling stop time is up.

4. Then, the battery relay is turned OFF and the engine stops. (Refer to SYSTEM / Electrical System.)

Conditions: x Auto Idling Stop setting: ON x Accelerator Pedal (1): Not depressed x Parking Brake: Engaged x Brake Pedals (44, 46): Not depressed (Reference: Pressure Sensor (Brake Secondary Pressure) (45): 0.16 MPa, 1.6 kgf/cm2, 23 psi or less) x Forward/Reverse Switch (27): Neutral Position (25) x Front Attachment, Steering: Not operated (Reference: Pump Delivery Pressure Sensor (29): 5.0 MPa, 51 kgf/ cm2, 725 psi or less) x Overheat Alarm: OFF x Coolant Temperature Sensor (15): 95 °C, 203 °F or less x Hydraulic Oil Temperature Sensor (41): 95 °C, 203 °F or less x Torque Converter Oil Temperature Sensor (18): 115 °C, 239 °F or less x Except for Exhaust Filter Manual Regeneration x Abnormal communication of ECM (10) or Column Display Controller (4): None x Transmission learning: Not in progress x Engine Speed: 950 RPM (min-1) or more

T2-2-80

OFF or ACC position and restart the engine as is normally done.

SECTION 2 SYSTEM Group 2 Control System

115TNED-02-02-46

12345678910111213-

Accelerator Pedal Accelerator Pedal Sensor Main Controller (MC) (Main) Column Display Controller Controller Area Network (CAN) Air Conditioner Controller Maintenance Pro Dr. (MPDr.) Monitor Monitor Controller Engine Control Module (ECM) Engine Exhaust Temperature Sensor Engine Speed Sensor (Backup)

141516181921222324252627-

Main Controller (MC) (Sub) Coolant Temperature Sensor Transmission Torque Converter Oil Temperature Sensor Engine Speed Sensor Machine Speed Sensor Shift Up Switch Shift Down Switch Forward Position Neutral Position Reverse Position Forward/Reverse Switch

28- Joystick Steering System Switch 29- Pump Delivery Pressure Sensor 30- Torque Control Solenoid Valve 31- Parking Brake Solenoid Valve 32- Pressure Sensor (Parking Brake) 33- Parking Brake Switch 35- Power Mode Selector Switch 36- Travel Mode Selector Switch 37- AUTO 2 Mode 38- Manual Mode 39- AUTO 1 Mode

T2-2-81

40- Starter Key Switch 41- Hydraulic Oil Temperature Sensor 43- Auto Idling Stop Relay 44- Brake Pedal (Left) 45- Pressure Sensor (Brake Secondary Pressure) 46- Brake Pedal (Right) 47- Brake Pedal (Right) Switch 48- Buzzer

SECTION 2 SYSTEM Group 2 Control System Secondary Steering Control (Option)

NOTE: When secondary steering pump delivery

Purpose: The secondary steering is used to steer the machine in the event that the engine stops running. The secondary steering control uses an electric motor to drive an auxiliary pump to provide oil to steer the machine.

pressure sensor (16) malfunctions, monitor controller (4) flashes the emergency indicator at monitor panel (3).

Normal operation: 1. MC (Sub) (8) receives a signal from steering pressure switch (15). (Refer to Low Steering Oil Pressure Indicator Control.)

Automatic operation check when the engine starts: 1. In the event of low steering pressure, Main Controller (MC) (Sub) (8) receives a signal from secondary steering pump delivery pressure sensor (16).

2. MC (Main) (1) receives a signal from machine speed sensor (12).

3. If the steering cannot be operated, MC (Sub) (8) activates secondary steering motor (20) to turn and operates secondary steering pump (21) ON for 60 seconds. The machine speed must be at or over 5 km/h (3.1 mph) to operate (If it is not at or above this pressure, steering pressure switch (15) turns OFF).

2. Three seconds after the engine starts, MC (Sub) (8) automatically turns secondary steering pump relay (19) ON for a maximum of 2 seconds.

3. Secondary steering motor (20), and then secondary steering pump (21) operate for a maximum of 2 seconds.

4. Pressurized oil from secondary steering pump (21) is supplied to the steering circuit and makes the steering operation possible for 60 seconds.

4. MC (Sub) (8) turns secondary steering pump relay (19) OFF when secondary steering pump delivery pressure rises above 4.8 MPa, 49 kgf/cm2, 696 psi or more (normal pressure range) with secondary steering pump (21) operating.

5. While the above items are occurring, MC (Main) (1) sends the signals to monitor controller (4) via CAN communication (5).

5. When secondary steering pump relay (19) is ON, monitor controller (4) indicates that it is operating on monitor (3).

6. Monitor controller (4) indicates that the secondary steering is operating via the indicator in monitor (3).

6. Monitor controller (4) secondary steering indicator flashes to indicate that the secondary steering pump delivery pressure at sensor (16) is below 4.8 MPa (49 kgf/cm2, 696 psi) or less (abnormal pressure) while secondary steering pump (21) is in operation.

NOTE: The secondary steering control can be adjusted

T2-2-82

or turned ON/OFF with Maintenance Pro Dr.

SECTION 2 SYSTEM Group 2 Control System

95TNED-02-02-47

a-

To Steering Valve

123456-

Main Controller (MC) (Main) Column Display Controller Monitor Monitor Controller Controller Area Network (CAN) Engine Control Module (ECM)

789111213-

Engine Main Controller (MC) (Sub) Engine Speed Sensor Transmission Machine Speed Sensor Pump Delivery Pressure Sensor

14- Secondary Steering Check Switch 15- Steering Pressure Switch 16- Secondary Steering Pump Delivery Pressure Sensor 17- Accelerator Pedal

T2-2-83

18- Accelerator Pedal Sensor 19- Secondary Steering Pump Relay 20- Secondary Steering Motor 21- Secondary Steering Pump

SECTION 2 SYSTEM Group 2 Control System (Blank)

T2-2-84

SECTION 2 SYSTEM Group 2 Control System Combined Electric and Hydraulic Control Circuit The combined electric and hydraulic control circuits have the following controls. x Bucket Auto Leveler Control x Lift Arm Float Control

T2-2-85

SECTION 2 SYSTEM Group 2 Control System Bucket Auto Leveler Control Purpose: The bucket auto leveler control automatically levels the bucket horizontal to start digging in a pile, and permits bucket roll back while engaging the pile and filling the bucket.

Operation: 1. Bar (3) is located to the front of bucket proximity switch (2) while dumping the bucket.

2. When the bucket control lever is moved from the dump position (bar 3 is close to the proximity switch while dumping) to the level position by tilting it back (roll back), bar (3) moves past the bucket proximity switch (2). With bar (3) in front of the bucket proximity switch (2), the electrical detent circuit is energized by current (a) from fuse #16 in fuse box B. Note that proximity switch (2) detects the position of the bar, turns ON bucket leveler relay (12), and turns ON electromagnet (5) in pilot control valve (4) when the bar is close to it.

3. Therefore, the bucket control lever is held by electromagnet (5) on the bucket roll back side, and pressurized oil from pilot valve (4) moves bucket spool (9) in multiple control valve (7).

4. Pressurized oil from main pump (10) flows to bucket cylinder (1) through bucket spool (9) in multiple control valve (7) and tilts the bucket.

5. When bar (3) is moved away from bucket proximity switch (2), bucket proximity switch (2) turns OFF. Electromagnet (5) on the bucket roll back side turns OFF and the bucket control lever returns to the neutral position.

6. Therefore, when bucket spool (9) in multiple control valve (7) returns to the neutral position, bucket cylinder (1) stops.

7. This automatically permits the bucket to be leveled.

T2-2-86

SECTION 2 SYSTEM Group 2 Control System

95TNED-02-02-60

a-

From Fuse Box B (Fuse #16)

b-

From Brake Circuit (Accessory Pump via Reducing Valve)

123-

Bucket Cylinder Bucket Proximity Switch Bar

4-

Pilot Valve (Bucket Control Lever) Electromagnet on Bucket Roll Back Side

5-

78910-

T2-2-87

Multiple Control Valve Lift Arm Spool Bucket Spool Main Pump

11- Hydraulic Tank

SECTION 2 SYSTEM Group 2 Control System Lift Arm Float Control Purpose: Permits floating up and down movement of the lift arm in response to the ground level external loads for snow removing and road cleaning Operation: 1. When the lift arm control lever is moved to the float position (farther position than the lift arm lowering position), the Main Controller (MC) turns ON, and electromagnet (2) on the lift arm lowering side is turned ON by current (a) from fuse #16 in fuse box B. 2. Therefore, the lift arm control lever is held by electromagnet (2) on the lift arm lowering side.

3. Pressurized oil from pilot valve (3) moves lift arm spool (8) in multiple control valve (7) to the float position (farthest down position).

4. Pressurized oil from main pump (10), and from lift arm cylinder (1) at both base and rod ends are all routed to hydraulic tank (11) through lift arm spool (8).

5. Therefore, as the circuit is opened between lift arm cylinder (1) and hydraulic tank (11), the lift arm can move freely up and down depending on the external forces on the lift arm.

6. The lift arm control lever returns to the neutral position when it is pulled more strongly than the magnetic force of electromagnet (2) on the lift arm lowering side.

7. Therefore, lift arm spool (8) in multiple control valve (7) returns to the neutral position and the lift arm float control is deactivated.

T2-2-88

SECTION 2 SYSTEM Group 2 Control System

95TNED-02-02-61

a-

From Fuse Box B (Fuse #16)

b-

From Brake Circuit (Accessory Pump via Reducing Valve)

12-

Lift Arm Cylinder Electromagnet on Lift Arm Lowering Side

3-

Pilot Valve (Lift Arm Control Lever) Multiple Control Valve

7-

8- Lift Arm Spool 9- Bucket Spool 10- Main Pump

T2-2-89

11- Hydraulic Tank

SECTION 2 SYSTEM Group 2 Control System (Blank)

T2-2-90

SECTION 2 SYSTEM Group 3 ECM System Outline Engine Control Module (ECM) (19) receives signals from the sensors and Main Controllers (MC) (29, 30).

ECM (19) processes this information and operates twoway valve (20), pressure control valve (PCV) (26), Exhaust Gas Recirculation (EGR) motors (16), and controls supply pump (24), injector (21), and EGR valves.

Supply pump (24) is activated by the engine and produces high-pressure fuel. Common rail (23) distributes this high-pressure fuel produced by supply pump (24) to injector (21) for each engine cylinder to inject the fuel to power the engine.

VGT Engine Control Module (ECM) MC (Main) MC (Sub)

Common rail

Crank shaft

Cam shaft

Fuel tank

Supply pump

Injector 123456-

7-

Fuel Filter Pressure Sensor Atmospheric Pressure Sensor Intake-Air Temperature Sensor Mass Air Flow (MAF) Sensor Exhaust Filter Differential Pressure Sensor Diesel Oxidation Catalyst (DOC) Exhaust Temperature Sensor Diesel Particulate Filter (DPF) Exhaust Temperature Sensor

891011121314-

Crank Speed Sensor Cam Angle Sensor Coolant Temperature Sensor Boost Pressure Sensor Boost Temperature Sensor Engine Oil Pressure Sensor Intake Manifold Temperature Sensor 15- EGR Motor Position Sensor 16- EGR Motor 17- Intake Throttle Position Sensor

1819202122232425262728-

T2-3-1

Intake Throttle Engine Control Module (ECM) Two-Way Valve Injector Common Rail Pressure Sensor Common Rail Supply Pump Fuel Tank Pressure Control Valve (PCV) Fuel Temperature Sensor Controller Area Network (CAN)

95Z7-02-03-01EC

29- Main Controller (MC) (Main) 30- Main Controller (MC) (Sub) 31- Variable Geometry Turbo (VGT) Controller 32- Variable Geometry Turbo (VGT) Actuator

SECTION 2 SYSTEM Group 3 ECM System Fuel Injection Control Engine Control Module (ECM) (19) monitors the engine operation status according to the signals from each sensor and Main Controllers (MC) (29, 30), and provides outputs for fuel injection amount rate, injection pressure, injection timing, and injection rate and frequency.

The ECM uses two way valve (20) and pressure control valve (PCV) (26) to operate pressure and injection.

Two-way valve (20) controls: Fuel Injection Volume Fuel Injection Timing Fuel Injection Rate and Frequency PCV (26) controls: Fuel Injection Quantity

T2-3-2

SECTION 2 SYSTEM Group 3 ECM System

VGT Engine Control Module (ECM) MC (Main) MC (Sub)

Common rail

Crank shaft

Cam shaft

Fuel tank

Supply pump

Injector 95Z7-02-03-01EC

123456-

7-

Fuel Filter Pressure Sensor Atmospheric Pressure Sensor Intake-Air Temperature Sensor Mass Air Flow (MAF) Sensor Exhaust Filter Differential Pressure Sensor Diesel Oxidation Catalyst (DOC) Exhaust Temperature Sensor Diesel Particulate Filter (DPF) Exhaust Temperature Sensor

891011121314-

Crank Speed Sensor Cam Angle Sensor Coolant Temperature Sensor Boost Pressure Sensor Boost Temperature Sensor Engine Oil Pressure Sensor Intake Manifold Temperature Sensor 15- EGR Motor Position Sensor 16- EGR Motor 17- Intake Throttle Position Sensor

1819202122232425262728-

T2-3-3

Intake Throttle Engine Control Module (ECM) Two-Way Valve Injector Common Rail Pressure Sensor Common Rail Supply Pump Fuel Tank Pressure Control Valve (PCV) Fuel Temperature Sensor Controller Area Network (CAN)

29- Main Controller (MC) (Main) 30- Main Controller (MC) (Sub) 31- Variable Geometry Turbo (VGT) Controller 32- Variable Geometry Turbo (VGT) Actuator

SECTION 2 SYSTEM Group 3 ECM System Fuel Injection Volume Control Purpose: The fuel injection volume control provides the best fuel injection rate.

Operation: 1. Engine Control Module (ECM) (19) reads the engine speed signals from crank speed sensor (engine speed sensor, main) (8) and cam angle sensor (engine speed sensor, sub) (9).

2. Main Controllers (MC) (29, 30) receive signals from accelerator pedal sensor (45), various sensors and switches, and calculate and send signals to ECM (19) to adjust the target speed as needed for the present operation. (Refer to SYSTEM / Control System.)

3. ECM (19) controls the fuel injection volume by turning two-way valve (20) in injector (21) ON or OFF according to the engine speed and the signals from MCs (29, 30).

T2-3-4

SECTION 2 SYSTEM Group 3 ECM System

MC (Main)

ECM MC (Sub)

2-way valve

95Z7-02-03-02EC

123456-

78910111213-

Fuel Filter Pressure Sensor Atmospheric Pressure Sensor Intake-Air Temperature Sensor Mass Air Flow (MAF) Sensor Exhaust Filter Differential Pressure Sensor Diesel Oxidation Catalyst (DOC) Exhaust Temperature Sensor Diesel Particulate Filter Exhaust Temperature Sensor Crank Speed Sensor Cam Angle Sensor Coolant Temperature Sensor Boost Pressure Sensor Boost Temperature Sensor Engine Oil Pressure Sensor

14- Intake Manifold Temperature Sensor 15- EGR Motor Position Sensor 16- EGR Motor 17- Intake Throttle Position Sensor 18- Intake Throttle 19- Engine Control Module (ECM) 20- Two-Way Valve 21- Injector 22- Common Rail Pressure Sensor 23- Common Rail 24- Supply Pump 25- Fuel Tank 26- Pressure Control Valve (PCV) 27- Fuel Temperature Sensor 28- Controller Area Network (CAN) 29- Main Controller (MC) (Main)

30313233343536373839404142-

T2-3-5

Main Controller (MC) (Sub) Monitor Controller Column Display Controller Variable Geometry Turbo (VGT) Controller VGT Actuator Pump Delivery Pressure Sensor Declutch Position Switch Power Mode Selector Switch Driving Mode Switch Lift Arm (Boom) Angle Sensor Pressure Sensor (Parking Brake) Pressure Sensor (Lift Arm (Boom) Raise) Pressure Sensor (Bucket Roll Back)

43- Pressure Sensor (Bucket Dump) 44- Pressure Sensor (Brake Secondary Pressure) 45- Accelerator Pedal Sensor 46- Hydraulic Oil Temperature Sensor 49- Machine Speed Sensor 50- Shift Up Switch 51- Shift Down Switch 52- Forward/Reverse Switch

SECTION 2 SYSTEM Group 3 ECM System Fuel Injection Pressure Control Purpose: The fuel injection pressure control provides the best fuel injection pressure.

Operation: 1. Engine Control Module (ECM) (19) calculates the required fuel injection volume according to the engine speed signal from crank speed sensor (engine speed sensor, main) (8) and cam angle sensor (engine speed sensor, sub) (9) and signals from MCs (29, 30). (Refer to Fuel Injection Volume Control.)

2. Common rail pressure sensor (22) sends signals to ECM (19).

3. ECM (19) calculates the best fuel pressure for common rail (23) from the engine speed, fuel injection volume, and common rail pressure sensor (22) signal.

4. ECM (19) sends a signal to pressure control valve (PCV) (26) in supply pump (24) and supplies fuel at the rate of optimum pressure and volume within common rail (23).

5. Pressurized fuel in common rail (23) is supplied to injector (21), and this controls the fuel injection pressure.

T2-3-6

SECTION 2 SYSTEM Group 3 ECM System

MC (Main)

ECM MC (Sub)

Common rail

Supply pump

95Z7-02-03-03EC

123456-

78910111213-

Fuel Filter Pressure Sensor Atmospheric Pressure Sensor Intake-Air Temperature Sensor Mass Air Flow (MAF) Sensor Exhaust Filter Differential Pressure Sensor Diesel Oxidation Catalyst (DOC) Exhaust Temperature Sensor Diesel Particulate Filter Exhaust Temperature Sensor Crank Speed Sensor Cam Angle Sensor Coolant Temperature Sensor Boost Pressure Sensor Boost Temperature Sensor Engine Oil Pressure Sensor

14- Intake Manifold Temperature Sensor 15- EGR Motor Position Sensor 16- EGR Motor 17- Intake Throttle Position Sensor 18- Intake Throttle 19- Engine Control Module (ECM) 20- Two-Way Valve 21- Injector 22- Common Rail Pressure Sensor 23- Common Rail 24- Supply Pump 25- Fuel Tank 26- Pressure Control Valve (PCV) 27- Fuel Temperature Sensor 28- Controller Area Network (CAN) 29- Main Controller (MC) (Main)

30313233343536373839404142-

T2-3-7

Main Controller (MC) (Sub) Monitor Controller Column Display Controller Variable Geometry Turbo (VGT) Controller VGT Actuator Pump Delivery Pressure Sensor Declutch Position Switch Power Mode Selector Switch Driving Mode Switch Lift Arm (Boom) Angle Sensor Pressure Sensor (Parking Brake) Pressure Sensor (Lift Arm (Boom) Raise) Pressure Sensor (Bucket Roll Back)

43- Pressure Sensor (Bucket Dump) 44- Pressure Sensor (Brake Secondary Pressure) 45- Accelerator Pedal Sensor 46- Hydraulic Oil Temperature Sensor 49- Machine Speed Sensor 50- Shift Up Switch 51- Shift Down Switch 52- Forward/Reverse Switch

SECTION 2 SYSTEM Group 3 ECM System Operation of Fuel Injection:

Fuel Injection Timing Control

1. Fuel pressure from the common rail is always applied at nozzle (6) in the injector.

Purpose: The fuel injection timing control calculates the best fuel injection timing.

Operation: 1. Engine Control Module (ECM) calculates the fuel injection timing according to the engine speed and fuel injection volume.

2. ECM turns two-way valve (2) in the injector ON/OFF according to fuel injection timing.

Fuel Injection Rate and Frequency Control

2. When turning ON electromagnetic coil (9) in twoway valve (2), the high-pressure fuel in control chamber (5) returns to the fuel tank through orifice A (4).

3. This raises hydraulic piston (10) and causes nozzle (6) to open and start injection.

4. When turning OFF electromagnetic coil (9) in twoway valve (2), valve (8) is closed and the circuit to the fuel tank is closed. High-pressure fuel from the common rail flows to control chamber (5) through orifice B (12).

5. High-pressure fuel flows to control chamber (5), and hydraulic piston (10) is lowered by the pressure difference due to movement of hydraulic piston (10). This closes nozzle (6) and fuel injection stops.

Purpose: The fuel injection rate and frequency control improves combustion in the engine cylinder.

Operation: 1. The injector first injects a small amount of fuel (known as pilot injection) which ignites.

2. After pilot injection and preliminary flame, the injector injects fuel through this flame multiple times, depending on operation requirements (main injection).

3. ECM controls the fuel injection timing and fuel injection volume by turning two-way valve (2) in the injector ON/OFF.

T2-3-8

SECTION 2 SYSTEM Group 3 ECM System 1. Two-Way Valve: ON

2. Injection Start 1

1 9

2

2

8 7

3

7

3

4

5 10 11

6

6

TDAA-02-03-014

TDAA-02-03-015

3. Two-Way Valve: OFF

4. Injection Stop 1

1 2

9

2

8 7

7 5

12

10

10

6

6

TDAA-02-03-017

TDAA-02-03-016

123-

From ECM Two-Way Valve Returning to Fuel Tank

456-

Orifice A Control Chamber Nozzle

789-

T2-3-9

From Common Rail Valve Electromagnetic Coil

10- Hydraulic Piston 11- Spring 12- Orifice B

SECTION 2 SYSTEM Group 3 ECM System EGR Control Purpose: The Exhaust Gas Recirculation (EGR) control re-circulates a part of exhaust gas (1) to intake manifold (2) and combines it with intake-air (4). This lowers the cylinder combustion temperature and reduces the level of oxide of nitrogen (NOx).

fNOTE: EGR: Exhaust Gas Recirculation fNOTE: MAF (Mass Air Flow) sensor integrates an

Operation: EGR Gas Volume Control 1. ECM (5) determines the EGR gas volume according to engine RPM's (min-1), fuel injection volume, intake air volume, coolant temperature, atmospheric pressure, and intake-air temperature, etc.

2. ECM (5) sends an output signal to EGR motor (6), to open EGR valve (7). This diverts a small amount of EGR gas to intake manifold (2) to blend with intakeair (4).

3. At the same time, ECM (5) senses the size of the opening amount of EGR valve (6) by using EGR position sensor (8). It maintains the opening gap at the required position, depending on the operational requirements.

EGR Gas Cooling 1. EGR gas is cooled by EGR cooler (3) in the EGR gas passage.

2. This cooled EGR gas is combined with intake-air (4) to lower the combustion temperature in the cylinder, and NOx emissions are reduced.

T2-3-10

intake-air temperature sensor (10). The MAF sensor reads intake-air flow from the air cleaner and the air temperature.

Air flow will cool the heated sensor wire, and change the resistance, providing a signal to indicate air volume.

When intake the air temperature is cold, the resistance is high When intake the air temperature is hot, the resistance is low

SECTION 2 SYSTEM Group 3 ECM System

Coolant Outlet

Coolant Inlet

95Z7-02-03-04

123456-

Exhaust Intake Throttle Valve EGR Cooler Intake Air Engine Control Module (ECM) EGR Motor

789-

EGR Valve EGR Position Sensor Mass Air Flow (MAF) Sensor (Intake-Air Temperature Sensor)

10- Intake Manifold Temperature Sensor 11- Atmospheric Pressure Sensor 12- Common Rail Pressure Sensor 13- Coolant Temperature Sensor

T2-3-11

14- Crank Speed Sensor (Engine Speed Sensor, Main) 15- Cam Angle Sensor (Engine Speed Sensor, Sub) 16- Boost Temperature Sensor 17- Boost Pressure Sensor

SECTION 2 SYSTEM Group 3 ECM System Preheating Control Purpose: The cylinder preheat system controls glow plugs, allows easier cold weather starting and reduces white smoke and noise at start up. And it adjusts length of time the glow plugs are used to stabilize engine idle after start up.

1 3

Operation: 1. Engine Control Module (ECM) (2) receives input signals from coolant temperature sensor (1).

2. When the key switch is set to the ON position, current from terminal M (3) in the key switch flows to glow plug relay (6).

4

2

3. ECM (2) connects the ground circuit to energize glow plug relay (6) according to signals from coolant temperature sensor (1), and controls the length of time that glow plug relay (6) heats glow plugs (7).

5 6

7

95TJAA-02-03-003

12345-

T2-3-12

Coolant Temperature Sensor ECM From Key Switch Terminal M Fuse Box From +24 VDC source

67-

Glow Plug Relay Glow Plug

SECTION 2 SYSTEM Group 3 ECM System Variable Turbocharger Control Purpose: The variable geometry turbocharger changes the nozzle opening inside of the turbine housing depending on the engine speed, engine load, and adjusts the inlet area of turbo.

Therefore, the rotation speed of turbo charger compressor is changed and the intake air pressure is regulated as required for the engine.

This results in intake air efficiently for a wide variety of engine speeds. (Refer to Engine Manual.)

T2-3-13

SECTION 2 SYSTEM Group 3 ECM System Exhaust Filter Outline Exhaust filter removes particulate matter (PM) and other exhaust substances from the diesel engine exhausts.

Exhaust filter consists of diesel oxidation catalyst (DOC) (1), diesel particulate filter (DPF) (2), and silencer (6).

DOC (1) oxidizes unburned fuel and raises exhaust temperature.

DPF (2) traps PM in form of soot, then burns and removes the PM by using high-temperature exhaust gas with DOC (1). DPF (2) and DOC (1) operate at the same time and this burns the soot from DPF (2), resulting in a light oil-free ash remaining.

After many self-cleaning cycles on the machine, the DPF will need to be removed and professionally cleaned. If it is damaged, or cannot be cleaned, it must be replaced.

Careful handling is required since the DPF internal material is ceramic and subject to cracking or breakage.

Exhaust filter is equipped with three sensors: DOC exhaust temperature sensor (3), DPF exhaust temperature sensor (4), and differential pressure sensor (7).

DOC exhaust temperature sensor (3) and DPF exhaust temperature sensor (4) measure the temperature before and after DOC (1). The signals from these sensors are used to effectively control the catalytic functions of both DOC (1) and DPF (2).

Differential pressure sensor (7) measures the differential pressure among DOC (1), DPF (2), and atmosphere and determines when DPF (2) is becoming clogged and will need to be cleaned.

Machine Front

95TNED-02-03-05DPF A-

Exhaust Gas

1-

Diesel Oxidation Catalyst (DOC) Diesel Particulate Filter (DPF)

2-

3-

Diesel Oxidation Catalyst (DOC) Exhaust Temperature Sensor

46-

T2-3-14

Diesel Particulate Filter (DPF) Exhaust Temperature Sensor Silencer

7-

Differential Pressure Sensor

SECTION 2 SYSTEM Group 3 ECM System Operation

fNOTE: Diesel oxidation catalyst (DOC) (1) is used during

1. Exhaust gas from the engine goes to diesel particulate filter (DPF) (2) through diesel oxidation catalyst (DOC) (1).

the required service level cleaning (regeneration) of the exhaust filter.

2. Diesel Particulate Matter (PM) is filtered out of the exhaust gas by DPF (2) as the exhaust gas flows through it.

3. The filtered exhaust gas is exhausted through the end of the filter.

4. This process traps the PM (soot) in DPF (2).

5. The PM (soot) must be burned up through the DPF cleaning process (known as regeneration).

Exhaust Filter Assembly 1

2

TDAA-02-03-012

Filtration

2

Soot deposits

2

Cleaning (Also known as "regeneration")

2

CO2

PM

PM

TDAA-02-03-006

1-

Diesel Oxidation Catalyst (DOC)

2-

Diesel Particulate Filter (DPF)

T2-3-15

SECTION 2 SYSTEM Group 3 ECM System Exhaust Filter Regeneration Control The exhaust filter regeneration control burns off the Particulate Matter (PM or also known as "soot") which has deposited in Diesel Particulate Filter (DPF) (5) by using hot exhaust gas. This process is referred to as "regeneration" ("cleaning").

The regeneration of the exhaust filter consists of "Passive Regeneration" and "Active Regeneration". "Active Regeneration" is a form of required regeneration that starts automatically (auto regeneration) or initiated either by the operator (manual regeneration). (Refer to SYSTEM / Control System.)

Passive Regeneration (Self cleaning while in operation) 1. Passive regeneration (self cleaning) works by using normal high exhaust temperatures that come with medium to heavy workloads.

2. A catalyst is more activated in case the exhaust temperature at the inlet of DPF (5) is higher, increasing regeneration amount.

Auto Regeneration (Automatic Cleaning): Required Auto-regeneration is automatically done 8 hours from the last regeneration. (Timed Regeneration) A required Auto-regeneration is done when the pressure differential sensor (4) indicates that the pressure difference between the front and back of the DPF (5) has exceeded acceptable limits prior to this 8 hour time frame. (Pressure Differential Regeneration) Manual Regeneration: When the Exhaust Filter Regeneration Request is displayed on the monitor, the regeneration is manually done as follows: Leave the accelerator pedal up (do not use throttle pedal), Activate the control lever lock switch, Place the forward/reverse lever in neutral, Place the forward/reverse switch in neutral, Apply the parking brake, Press the exhaust filter regeneration switch Follow the prompts on the monitor panel screen. It will indicate when this process is over.

Active Regeneration (Required cleaning) 1. Fuel is injected (post injection (11)) into the hot exhaust gas by diesel engine cylinder (7) and the exhaust gas mixed with unburned fuel is supplied to DOC (6).

2. DOC (6) oxidizes unburned fuel and raises DPF (5) temperature.

3. The exhaust temperature at the inlet side of DPF (5) increases to about 580 to 600 °C (1,075 to 1,100 °F) and DPF (5) is cleaned.

fNOTE: When the exhaust temperature before DPF (5)

is above 250 °C (480 °F) post injection (11) is used. When the exhaust temperature before DPF (5) is 250 °C (480 °F) or less, after-injection of the engine cylinder diesel fuel injectors (10) is used and raises the exhaust temperature.

After-injection (10) can be used only when the engine coolant temperature is 70 °C (160 °F) or more.

T2-3-16

SECTION 2 SYSTEM Group 3 ECM System

1 4 2

3

6

5 TDAA-02-03-13KC

7

TDAA-02-03-022KC

8

12-

Engine Control Module (ECM) Diesel Oxidation Catalyst (DOC) Exhaust Temperature Sensor

9

345-

10

Diesel Particulate Filter (DPF) Exhaust Temperature Sensor Pressure Differential Sensor Diesel Particulate Filter (DPF)

11

6789-

T2-3-17

Diesel Oxidation Catalyst (DOC) Cylinder Pilot Injection Main Injection

10- After-Injection 11- Post Injection

SECTION 2 SYSTEM Group 3 ECM System (Blank)

T2-3-18

SECTION 2 SYSTEM Group 4 Hydraulic System Outline Hydraulic system is divided into the pilot circuit, main circuit, and secondary steering circuit (option).

Pilot Circuit: Power Source Accessory (Pilot) Pump

Oil Control Method Unloader (Brake Charge) Valve Combination Valve (Brake Manifold, Solenoid Valve) Pilot Valve Fan Control Valve Priority Hammer Valve

Supplied to Service Brake Circuit Parking Brake Circuit Auto Brake Circuit Lift Arm / Bucket Operation Control Circuit Fan Motor Lift Arm / Bucket Cylinders

Oil Control Method Steering Valve Multiple Control Valve

Supplied to Steering Cylinder Lift Arm / Bucket Cylinder Pump Control Circuit Ride Control Circuit Exhaust Filter Regeneration Control Circuit

Main Circuit: Power Source Main Pump

Ride Control Valve (Option)

Secondary Steering Circuit (Option): Power Source Secondary Steering Pump

Oil Control Method Steering Valve

Supplied to Steering Cylinder

T2-4-1

SECTION 2 SYSTEM Group 4 Hydraulic System Pilot Circuit Outline: Pressurized oil from pilot pump (16) is used in order to operate the following circuits. x Brake Priority Circuit x Service Brake Circuit x Parking Brake Circuit x Lift Arm / Bucket Operation Control Circuit x Fan Motor Circuit

T2-4-2

SECTION 2 SYSTEM Group 4 Hydraulic System

95TNED-02-04-04

T2-4-3

SECTION 2 SYSTEM Group 4 Hydraulic System Brake Priority Circuit Purpose: The brake circuit supplies pressurized oil from accessory (pilot) pump (1) to service brake circuits (A, B) through unloader (brake charge) valve (2) preferentially and maintains the brake performance.

9. Pressurized oil supplied to priority hammer valve (11) is used to operate the following circuits. x Fan Circuit (C) x Loading Circuit (D) x Accessory Pump Control Circuit (E)

y Outline

10. Pressurized oil supplied to rear service brake circuit (B) is used to operate the following circuits.

1. Pressurized oil from accessory pump (1) is supplied to unloader valve (2).

2. Valve 1 (3) supplies pressurized oil from accessory pump (1) to service brake circuits (A, B) with priority to the brake circuits.

3. Orifice 1 (4) controls the oil flow supplied to the service brake circuits.

4. Valve 2 (5) controls the set pressure of valve 1 (3).

5. Pressurized oil is supplied through orifice 1 (4) to service brake circuits (A, B) via reducing valve (7) and check valve (8).

6. At the same time, pressurized oil for brake circuit is accumulated in accumulators (9, 10).

7. Unloader valve (2) shifts valve 1 (3) according to the pressure amount charged in service brake accumulators (9, 10) (or brake pedal application angle).

8. Pressurized oil from accessory pump (1) is supplied to priority hammer valve (11).

T2-4-4

x Parking Brake Circuit (F) x Lift Arm / Bucket Operation Control Circuit (G) x Lock Valve Control Circuit (H) x Main Pump Control Circuit (J)

SECTION 2 SYSTEM Group 4 Hydraulic System Brake Priority Circuit

To Rear Brake

To Fan To Multiple Control Valve

To Front Brake

95TNED-02-04-05

ABCD-

Rear Service Brake Circuit Front Service Brake Circuit To Fan Circuit To Loading Circuit

E

123456-

Accessory (Pilot) Pump Unloader (Brake Charge) Valve Valve 1 Orifice 1 Valve 2 Orifice 2

789-

F-

To Accessory Pump Control Circuit To Parking Brake Circuit

Reducing Valve Check Valve Rear Service Brake Accumulator 10- Front Service Brake Accumulator

GHJ-

To Lift Arm / Bucket Operation Control Circuit Lock Valve Control Circuit Main Pump Control Circuit

11- Priority Hammer Valve 12- Main Pump (Regulator) 13- Front Control Lever Lock Solenoid 14- Parking Brake Solenoid 15- Auto Brake Solenoid

T2-4-5

16- Parallel/Tandem Switching Solenoid 17- Shuttle Valve for Accessory Pump Control

SECTION 2 SYSTEM Group 4 Hydraulic System y When the service brake is not applied 1. Valve 1 (3) in unloader (brake charge) valve (2) closes the circuit by the spring force.

10. Therefore, the pressure (a) at the top side (spring side) of valve 1 (3) decreases.

2. Pressurized oil from accessory (pilot) pump (1) is supplied to reducing valve (7) through orifice 1 (4).

11. When the pressure at the top side (spring side) of valve 1 (3) along with the spring force become lower than the pressure at the bottom side of valve 1 (3), valve 1 (3) moves to open the circuit.

3. Reducing valve (7) sends pressurized oil to service brake circuits (A, B) via check valve (8).

12. Consequently, pressurized oil from accessory pump (1) is supplied to priority hammer valve (11).

4. At the same time, pressurized oil for brake circuit is accumulated in accumulators (9, 10).

5. Pressurized oil from orifice 1 (4) also goes to valve 2 (5) through orifice 2 (6).

6. In addition, pressurized oil in front brake circuit (B) is sent to valve 2 (5) to operate valve 2 (5).

7. When service brake is not operated, the oil pressure in service brake accumulators (9, 10) (front and rear) increases due to pressurized oil from accessory pump (1).

8. When the circuit pressure in front brake circuit (B) increases over the specified value (reaches the cutout pressure), valve 2 (5) opens the circuit.

9. This permits the pressurized oil to operate valve 1 (3) to be sent to hydraulic tank (18) through valve 2 (5).

T2-4-6

SECTION 2 SYSTEM Group 4 Hydraulic System y Service brake is released

95TNED-02-04-30

AB-

Rear Service Brake Circuit Front Service Brake Circuit

12345-

Accessory (Pilot) Pump Unloader (Brake Charge) Valve Valve 1 Orifice 1 Valve 2

6789-

Orifice 2 Reducing Valve Check Valve Rear Service Brake Accumulator

10- Front Service Brake Accumulator 11- Priority Hammer Valve 18- Hydraulic Tank

T2-4-7

SECTION 2 SYSTEM Group 4 Hydraulic System y When the service brake is applied 1. When the brake is applied repeatedly the accumulator oil pressure (9, 10) (front and rear) decreases.

2. When the circuit pressure in front brake circuit (B) decreases (reaches the cut-in pressure), valve 2 (5) moves to close the circuit.

3. Pressurized oil to operate valve 1 (3) is blocked by valve 2 (5).

4. Therefore, the pressure at the top side (spring side) of valve 1 (3) increases.

5. When the pressure at the top side (spring side) of valve 1 (3) along with the combined spring force inside this valve becomes higher than the pressure at the bottom side of valve 1 (3), valve 1 (3) moves to close the circuit.

6. Consequently, brake circuit supply pressure oil is sent to service brake circuits (A, B) (front and rear) through orifice 1 (4).

7. Unloader valve (2) supplies pressure oil from accessory (pilot) pump (1) to service brake circuits (A, B) by priority according to the brake application to keep a ready supply of accumulated brake oil pressure for brake application.

T2-4-8

SECTION 2 SYSTEM Group 4 Hydraulic System y Service brake is applied

95TNED-02-04-31

AB-

Rear Service Brake Circuit Front Service Brake Circuit

12345-

Accessory (Pilot) Pump Unloader (Brake Charge) Valve Valve 1 Orifice 1 Valve 2

6789-

Orifice 2 Reducing Valve Check Valve Rear Service Brake Accumulator

10- Front Service Brake Accumulator 11- Priority Hammer Valve 18- Hydraulic Tank

T2-4-9

SECTION 2 SYSTEM Group 4 Hydraulic System Service Brake Circuit y When the service brake is released

y When the service brake is applied 1. Pressurized oil from accessory (pilot) pump (1) is supplied to brake valve (25) through unloader (brake charge) valve (2) to apply the brake. (Refer to Brake Priority Circuit.)

2. Brake spools (28, 29) on top and bottom of brake valve (25) are connected by spring (27) and move according to brake pedal (C) application angle.

3. When brake pedal is applied and spools (28,29) are pushed down, the oil passage from port PA to port PB are opened and pressurized oil from the accumulator is sent to the brake piston chambers in the front/rear axle housing to apply brakes (23, 24).

4. Brake oil circuit pressures (A, B) flow through both of orifices (26) in brake valve (25) and works as the hydraulic reactive force to push back spools (28, 29).

5. When the sum of hydraulic reactive force and the load of spring (30) become balanced with those of spring (27), it returns spools (28, 29) to close the passage between A and B to hold the pressure.

6. By this operation, the load of springs by deflection are transmitted to the operator as pedal pressing force, and the pressure in proportion to the pedal application angle is obtained.

NOTE: Brake oil circuit pressure (A, B) is applied to

both front and rear brake circuits (23, 24) at the same time and both front and rear brake circuits operate simultaneously.

NOTE: Front / rear brake units (23, 24) are housed in the front / rear axles. (Refer to COMPONENT OPERATION / Axle.)

T2-4-10

1. The brake circuit oil (A, B) from unloader valve (2) is blocked by brake spools (28, 29) on top and bottom of brake valve (25).

2. When brake pedal (C) is not applied, brake operating pressure oil (A, B) returns to hydraulic tank (18) through front / rear brakes (23, 24) and brake spools (28, 29) on top and bottom of brake valve (25).

3. Therefore, front / rear brakes (23, 24) are released.

Pressurized oil from pump (1) is stored in the accumulators (9, 10), and sent to ports (PA, PB).

SECTION 2 SYSTEM Group 4 Hydraulic System y When the service brake is applied

95TNED-02-04-20

y When the service brake is released

95TNED-02-04-18

A-

Rear Brake Operating Pressure Oil

B-

Front Brake Operating Pressure Oil

129-

Accessory (Pilot) Pump Unloader (Brake Charge) Valve Rear Service Brake Accumulator

10- Front Service Brake Accumulator 18- Hydraulic Tank

C-

Brake Pedal

23242526-

Front Brake Rear Brake Brake Valve Orifice

T2-4-11

27282930-

Spring Brake Spool (Top) Brake Spool (Bottom) Spring

SECTION 2 SYSTEM Group 4 Hydraulic System Parking Brake Circuit y Outline:

y When parking brake is applied:

1. Pressurized oil, which is regulated by reducing valve (19) in combination valve (20), is supplied to the parking brake circuit to release the parking brake.

1. When parking brake switch (z) is turned ON (this deenergizes the circuit), parking brake solenoid valve (14) is moved to the left by the spring.

2. Parking brake release oil flows to parking brake solenoid valve (14).

2. Parking brake oil returns to hydraulic tank (18) through parking brake solenoid valve (14).

3. Parking brake solenoid valve (14) is energized or deenergized by operating parking brake switch (z) and applies or releases parking brake (21).

3. Therefore, parking brake (21) is applied by the spring (22) force. y When parking brake is released: 1. Parking brake solenoid valve (14) is moved to the right when parking brake switch (z) is turned OFF (this energizes the circuit).

2. Parking brake oil flows through parking brake solenoid valve (14) to parking brake (21).

3. Therefore, parking brake (21) is released as spring (22) is compressed.

NOTE: The parking brake is a spring apply, hydraulic release (SAHR) type brake unit, and releases when pressure is applied to it.

T2-4-12

SECTION 2 SYSTEM Group 4 Hydraulic System y Parking brake is applied

SW ON: De-energized

95TNED-02-04-07

y Parking brake is released

SW OFF: Energized

95TNED-02-04-08

x-

Parking brake is released

14- Parking Brake Solenoid Valve 18- Hydraulic Tank

y-

Parking brake is applied

19- Reducing Valve 20- Combination Valve

z-

Parking Brake Switch Signal

21- Parking Brake 22- Spring

T2-4-13

SECTION 2 SYSTEM Group 4 Hydraulic System Auto Brake Circuit 1. When the conditions are satisfied, Main Controller (MC) (Main) activates auto brake solenoid valve (30).

2. Auto brake solenoid valve (30) supplies the pilot oil from reducing valve (19) to brake valve (25) through orifice at adapter tee (31).

3. This pilot oil actuates the pilot piston and the spools in brake valve (28, 29), which works the same as depressing the brake pedal to apply service brake.

Thus, braking system is called "auto brake".

NOTE: Refer to Service Brake Circuit in this section for the braking circuit.

T2-4-14

SECTION 2 SYSTEM Group 4 Hydraulic System y Auto brake is applied

115Z7-02-04-01

a-

Auto Brake Signal from MC (Main)

19- Reducing Valve 25- Brake Valve

28- Brake Spool (Top) 29- Brake Spool (Bottom)

30- Auto Brake Solenoid Valve 31- Adapter with Orifices

T2-4-15

SECTION 2 SYSTEM Group 4 Hydraulic System Lift Arm (Boom) / Bucket Operation Control Circuit 7. Flow regulator valve (4) is provided between pilot valve (1) and multiple control valve (7). Flow regulator valve (4) is consist of dampening valve (5) and restriction valve (6).

1. Front control lever lock solenoid valve (16) moves to the right when front control lever lock switch (a) is set to the OFF position.

2. Pressurized oil from accessory (pilot) pump (15) is regulated by reducing valve (13) and supplied to pilot valve (1) through loading control lever lock solenoid valve (16).

8. When stopping the lift arm raise / lower operation, dampening valve (5) reduces the volume of the returning pilot oil from multiple control valve (7).

Consequently lift arm spool (18) quick movement is dampened so as not to suddenly come to a stop and shock the machine with inertia energy caused from a sudden stop. (Refer to Shock Damping Function When Stopping Lift Arm Raise / Lower Operation.)

3. Pilot valve (1) supplies the pilot pressure oil according to the operation of lift arm (boom) control lever (2) and bucket control lever (3) as oil is provided to multiple control valve (7).

4. Lift arm spool (17) and bucket spool (20) in multiple control valve (7) are shifted by pressurized oil to operate the lift arm / bucket.

9. When stopping bucket dump operation, restriction valve (6) reduces the volume of the returning pilot oil from multiple control valve (7). Consequently, bucket spool (20) quick movement is dampened so as not to suddenly come to a stop and shock the machine with inertia energy caused from a sudden stop.

5. Pressurized oil from main pump (14) moves the right and left lift arm cylinders (8, 9), and bucket cylinders (18, 19) by shifting lift arm spool (17) and bucket spool (20).

6. The lift arm and bucket are operated by the right and left lift arm cylinders (8, 9), and bucket cylinders (18, 19). (Refer to Main Circuit.)

NOTE: Refer to COMPONENT OPERATION / Pilot Valve

T2-4-16

and Multiple Control Valve.

SECTION 2 SYSTEM Group 4 Hydraulic System Loading System Oil Circuits

95TNED-02-04-16

a-

From Front Control Lever Lock Switch (OFF Signal)

b-

To Rear Service Brake Circuit

123456-

Pilot Valve Lift Arm (Boom) Control Lever Bucket Control Lever Flow Regulator Valve Dampening Valve Restriction Valve

789111213-

Multiple Control Valve Lift Arm Cylinder (Left) Lift Arm Cylinder (Right) Hydraulic Tank Unloader Valve Reducing Valve

14- Main Pump 15- Accessory Pump 16- Front Control Lever Lock Solenoid Valve 17- Lift Arm (Boom) Spool 18- Bucket Cylinder (Left)

T2-4-17

19- Bucket Cylinder (Right) 20- Bucket Spool

SECTION 2 SYSTEM Group 4 Hydraulic System y Shock Dampening Function When Stopping Lift Arm (Boom) Raise / Lower Operation

NOTE: When lowering the lift arm (boom), the items mentioned below take place.

1. The lift arm spool returns to the neutral position when releasing the lift arm raise lever.

2. Returning oil (Pia2) from lift arm spool flows through the lift arm raise circuit and orifice (21) of flow regulator valve (4).

3. Therefore, the pressure difference is generated at front and back of orifice (21) and dampening valve (5) moves to the left.

4. Returning oil (Pia2) from lift arm spool flows through dampening valve (5) and decreases the pressure.

5. Consequently, the quick movement of lift arm spool is dampened and the inertia shock that would have occurred due to the sudden stop of the lift arm is reduced.

NOTE: Shock dampening valve (5) buffers the return oil through port Pib2, and modulates to lift arm stop when lowering.

T2-4-18

SECTION 2 SYSTEM Group 4 Hydraulic System y Shock Dampening Circuit

1

2

3

11 5 5 4

6 21

21 TNED-02-04-045KC

PP1

Pia2

Pib2

PP1- From Manifold Valve (Pilot Pressurized Oil)

Pia2-From Lift Arm Raise Circuit (Pilot Pressurized Oil)

Pib2- From Lift Arm Lower Circuit (Pilot Pressurized Oil)

12-

34-

56-

Pilot Valve Lift Arm Control Lever

Bucket Control Lever Flow Regulator Valve

T2-4-19

Dampening Valve Restriction Valve

11- Hydraulic Tank 21- Orifice

SECTION 2 SYSTEM Group 4 Hydraulic System Fan Circuit 10. Anti-void valves (3) are provided in the fan motor circuit.

1. Pressurized oil from unloader valve (8) is supplied to the port (A) side of fan motor (2) through fan reverse rotation spool (4) in fan control valve (1).

Fan motor (2) rotates in normal.

2. When the fan reversing switch is turned ON, fan reverse rotation control solenoid valve (5) is shifted by signal (a) from the Main Controller (MC) (Sub).

3. Pressurized oil from fan reverse rotation control solenoid valve (5) shifts fan reverse rotation spool (4).

11. Anti-void valve (3) refills hydraulic oil from the returning oil and prevents cavitation from occurring when the pressure in the fan circuit decreases (the fan motor speed change, engine shutdown, etc.).

12. Returning oil from fan motor (2) returns to hydraulic tank (9) through the oil cooler.

4. Therefore, pressurized oil from unloader valve (8) is supplied to the port (B) side of fan motor (2) and fan motor (2) rotates in reverse.

5. MC (Sub) sends signal (b) and activates fan speed control solenoid valve (6) according to the signals from coolant temperature sensor and each oil temperature sensor.

6. When hydraulic oil temperature is low, pressurized oil from unloader valve (8) flows to hydraulic tank (9) through fan speed control solenoid valve (6).

7. This decreases the pressure between orifice (7) and fan speed control solenoid valve (6), which is supplied to accessory pump (10) as the load sensing pressure (Pls).

8. Accessory pump (10) decreases the pressurized oil delivery until the difference between load sensing pressure (Pls) and the output pressure (Po) becomes the specified level.

9. This decreases the fan motor (2) speed.

T2-4-20

SECTION 2 SYSTEM Group 4 Hydraulic System y Normal rotation

95TNED-02-04-35

y Reverse rotation

95TNED-02-04-52 a-

Fan Reverse Switch Signal (From MC)

b-

Fan Speed Control Valve Control Signal (From MC)

123-

Fan Control Valve Fan Motor Anti-Void Valve

45-

Fan Reverse Rotation Spool Fan Reverse Rotation Control Solenoid Valve

67-

T2-4-21

Fan Speed Control Solenoid Valve Orifice

8- Unloader Valve 9- Hydraulic Tank 10- Accessory Pump

SECTION 2 SYSTEM Group 4 Hydraulic System Main Circuit Outline: 1. Main pump (1) draws hydraulic oil from hydraulic tank (32) through suction filter (33) and delivers it to steering valve (8) and multiple control valve (13).

2. Pressurized oil from steering valve (8) is supplied to steering spool (9) according to the steering operation by meter-in compensation valve (40) and bleed-off compensation valve (41). (Refer to Steering Priority Circuit.)

3. Steering cylinders (10, 11) at right and left are moved by shifting steering spool (9). (Refer to Steering Operation Control Circuit.)

4. Returning oil from steering cylinders (10, 11) returns to hydraulic tank (32) through steering valve (8).

5. Pressurized oil in multiple control valve (13) moves bucket cylinder (18), lift arm (boom) cylinders (16), and attachments (29) (Option) by shifting bucket spool (19), lift arm spool (17), auxiliary spools (28) (Option). (Refer to Pilot Circuit, Lift Arm / Bucket Operation Control Circuit.)

6. Returning oil from each cylinder returns to hydraulic tank (32) through multiple control valve (13).

NOTE: Pressurized oil from main pump (1) is also

used to operate the pump control circuit, exhaust filter regeneration control, and parallel circuit flow rate control. Refer to the following sections for details.

T2-4-22

SECTION 2 SYSTEM Group 4 Hydraulic System

90TNED-02-04-01

18910-

Main Pump Steering Valve Steering Spool Steering Cylinder (Left)

11131617-

Steering Cylinder (Right) Multiple Control Valve Lift Arm (Boom) Cylinder Lift Arm (Boom) Spool

18192829-

T2-4-23

Bucket Cylinder Bucket Spool Auxiliary Spool (OPT) Attachments (OPT)

32334041-

Hydraulic Tank Suction Filter Meter-in Compensation Valve Bleed-off Compensation Valve

SECTION 2 SYSTEM Group 4 Hydraulic System Steering Priority Circuit Purpose: The steering priority circuit supplies pressurized oil from main pump (1) to steering valve (8) with priority to the steering circuit and steering remains operable at all times. y When not operating the steering 1. Pressurized oil from main pump (1) is supplied to steering valve (8) and multiple control valve (13).

2. When not operating the joystick steering lever, steering spool (9) in steering valve (8) is in the neutral position.

3. As pressurized oil from main pump (1) flows through meter-in compensation valve (40) and is blocked by steering spool (9), right and left steering cylinders (10, 11) do not move.

4. At the same time, pressurized oil flows to pilot line (40a) of meter-in compensation valve (40).

5. Meter-in compensation valve (40) is closed as the pressure in pilot line (40a) increases.

6. Pilot pressure (41a) opens bleed-off compensation valve (41) at multiple control valve (13).

7. Therefore, pressurized oil from main pump (1) flows through bleed-off compensation valve (41) to hydraulic tank (32) via the center bypass line.

T2-4-24

SECTION 2 SYSTEM Group 4 Hydraulic System y Steering Priority Circuit (No Steering)

95TNED-02-04-40

40a- Pilot pressurized Oil to Operate Meter-in Compensation Valve

41a- Pilot Pressurized Oil to Operate Bleed-off Compensation Valve

128-

9- Steering Spool 10- Steering Cylinder (Left) 11- Steering Cylinder (Right)

Main Pump Joystick Steering Pilot Valve Steering Valve

13- Multiple Control Valve 32- Hydraulic Tank 40- Meter-in Compensation Valve

T2-4-25

41- Bleed-off Compensation Valve

SECTION 2 SYSTEM Group 4 Hydraulic System y When operating the joystick steering lever (Right Turn) 1. When the joystick steering lever is moved to the right, pilot pressure oil via port (Pb) shifts steering spool (9) in steering valve (8). (Refer to / Steering Operation Control Circuit.)

5. Consequently, the flow rate of pressurized oil flowing to steering valve (8) from main pump (1) increases.

2. Pressurized oil is supplied to meter-in compensation valve (40) to control the flow rate of pressurized oil in the steering circuit in proportion to the movement of steering spool (9) in steering valve (8).

3. Pressurized oil in steering valve (8) flows out to bleed-off compensation valve (41) via port (LS1) (as pilot pressure oil (41b)).

4. This pilot pressure (41b) closes the oil passage in bleed-off compensation valve (41), and oil flow to the loading circuit is limited.

T2-4-26

SECTION 2 SYSTEM Group 4 Hydraulic System y Steering Priority Circuit (Right Turn)

115TNED-02-04-26

41b- Pressurized Oil to Operate Bleed-off Compensation Valve

Pb- Steering (Right) (Pilot Pressurized Oil)

128-

9- Steering Spool 10- Steering Cylinder (Left) 11- Steering Cylinder (Right)

Main Pump Joystick Steering Pilot Valve Steering Valve

12- Joystick Steering Control Valve 13- Multiple Control Valve 32- Hydraulic Tank

T2-4-27

40- Meter-in Compensation Valve 41- Bleed-off Compensation Valve

SECTION 2 SYSTEM Group 4 Hydraulic System Steering Operation Control Circuit y Outline: 1. Pressurized oil from main pump (10) or accessory pump (9) is sent via shuttle valve (5) to reducing valve (3), regulated to the specified pressure, and supplied to steering pilot valve (11) and joystick steering control valve (12).

2. When operating the joystick steering lever, steering pilot valve (11) supplies pilot oil to Pia or Pib port in joystick steering control valve (12). Accordingly, joystick steering control valve (12) supplies pilot pressure to steering valve (4).

3. Then, steering pilot oil is supplied to operate steering spool (6) in steering valve (4) to steer the machine.

4. Pressurized oil from the pump moves steering cylinders (1, 2) to the right and left by shifting steering spool (6).

5. Stop valves (7, 8) control joystick steering control valve (12) and limits steering operation to the right or left. (Refer to Steering Stop.)

NOTE Refer to COMPONENT OPERATION / Steering Pilot Valve and Steering Valve.

T2-4-28

SECTION 2 SYSTEM Group 4 Hydraulic System Steering System Oil Circuits

115TNED-02-04-50

1234-

Steering Cylinder (Left) Steering Cylinder (Right) Reducing Valve Steering Valve

5678-

Shuttle Valve Steering Spool Stop Valve (Left) Stop Valve (Right)

9101112-

T2-4-29

Accessory Pump Main Pump Steering Pilot Valve Joystick Steering Control Valve

13- Pilot Accumulator (Steering) 14- Hydraulic Tank

SECTION 2 SYSTEM Group 4 Hydraulic System y Steering (Right) Operation: 1. When the joystick steering lever is shifted to the right from the neutral position, steering pilot valve (11) supplies pressurized oil to Pib port of joystick steering control valve (12) based on the steering lever angle.

2. This moves the spool in joystick steering control valve (12) and connects the A2 port and P port, B2 port and T port, respectively. Pressurized oil flows to steering valve (4) through stop valve (right) (8), and shifts steering spool (6).

3. Steering spool (6) moves left. Pressurized oil from main pump (10) moves steering cylinders (1, 2) to the right and left and the machine turns right.

4. The machine steering angle and speed changes as the amount and speed of spool (6) change with movement of the joystick steering lever.

5. If the joystick steering lever operation is large, pressurized oil to operate the steering increases.

The machine steering range increases according to the amount of steering lever motion.

6. When the joystick steering lever speed is rapid, the pilot steering volume increases, resulting in greater pilot oil volume. The machine steering speed is increased as the moving speed of steering spool (6) becomes fast.

T2-4-30

SECTION 2 SYSTEM Group 4 Hydraulic System y Right Turn

115TNED-02-04-23

EF- To Multiple Control Valve (Bleed-off Compensation Valve) 124-

Steering Cylinder (Left) Steering Cylinder (Right) Steering Valve

678-

Steering Spool Stop Valve (Left) Stop Valve (Right)

9- Check Valve 10- Main Pump 11- Steering Pilot Valve

T2-4-31

12- Joystick Steering Control Valve 14- Hydraulic Tank

SECTION 2 SYSTEM Group 4 Hydraulic System y Steering Stop Operation (When Fully Turned Right): 1. When the joystick steering lever is shifted to the right from the neutral position, the machine turns right by operating right and left steering cylinders (1, 2). (Refer to Steering (Right) Operation.)

2. When the joystick steering lever is shifted all the way to the right, stop valve (right) (8) comes in contact with steering stopper and the steering stop valve is moved.

3. As pressurized oil to operate the steering is blocked by check valve (9) in stop valve (right) (8), it stops oil flow to steering valve (4).

4. Therefore, without pilot oil flow, steering spool (6) returns to the neutral position.

5. Consequently, pressurized oil from main pump (10) is not supplied to steering cylinders (1, 2).

6. Therefore, steering right turn is limited.

NOTE: Left steering operation is limited by steering stop valve (7).

T2-4-32

SECTION 2 SYSTEM Group 4 Hydraulic System y Full Right Turn

115TNED-02-04-51

EF- To Multiple Control Valve (Bleed-off Compensation Valve) 124-

Steering Cylinder (Left) Steering Cylinder (Right) Steering Valve

678-

Steering Spool Stop Valve (Left) Stop Valve (Right)

9- Check Valve 10- Main Pump 11- Steering Pilot Valve

T2-4-33

12- Joystick Steering Control Valve 14- Hydraulic Tank

SECTION 2 SYSTEM Group 4 Hydraulic System Neutral Circuit

Relief Circuit

1. When the front loading attachment levers are in neutral, pressurized oil from main pump (1) returns to hydraulic tank (32) through neutral circuit (30) of control valve (13).

1. Main relief valve (7) is provided in the main circuit between pump and cylinders.

2. Main relief valve (6) in steering valve (8) prevents the pressure inside the main circuit from increasing over the set pressure while operating the steering control lever.

Main relief valve (7) in control valve (13) prevents the pressure inside the main circuit from increasing over the set pressure while operating the loading control lever.

2. Parallel circuit (31) is provided in the circuit of control valve (13) so that the combined operation of lift arm / bucket is possible.

Flow Rate Control Circuit 1. Lift arm flow rate control valve (25) is provided in parallel circuit (31) between lift arm spool (17) and bleed-off compensation valve (41).

3. Overload relief valves (24) are provided in the cylinder circuit between control valve and actuator of the lift arm, bucket, and auxiliary circuits.

2. When proportional solenoid valve for parallel circuit flow rate control is activated, lift arm flow rate control valve (25) is shifted.

4. With the spool in the neutral position (when the front attachment control lever in neutral), overload relief valve (24) protects the system from pressure surges created by external loads from exceeding the set pressure.

3. Therefore, lift arm cylinder (16) oil flow is reduced and oil flow to bucket cylinder (18) increases.

As a result, the bucket speed increases. (Refer to SYSTEM / Lift Arm and Bucket Selection Circuit Control.)

5. In addition, overload relief valve (24) is equipped with make-up function. When the pressure in the actuator circuit decreases, overload relief valve (24) draws pressurized oil from hydraulic oil tank (32) and prevents cavitation from occurring.

4. Pump control valve (27) is provided in neutral circuit (30) of control valve (13).

6. Overload relief valves (5) with make-up function are provided in steering valve (8), having the same functions as overload relief valves (24) in multiple control valve (13).

Refer to COMPONENT OPERATION / Control Valve, and Steering Valve for these relief valve operation.

5. Pump control valve (27) supplies pressurized oil from main pump (1) to the regulator of pump device and increases/decreases the pump delivery flow rate. (Refer to Pump Control Circuit.)

Other Circuits Load check valve (21) prevents pressurized oil from backflow in either the bucket circuit between bucket spool (19) and bucket cylinder (18), the lift arm (boom) circuit between boom spool (17) and boom cylinders (16), or the steering circuit between steering spool (9) and steering cylinders (10).

T2-4-34

SECTION 2 SYSTEM Group 4 Hydraulic System Circuit Features

115TNED-02-04-02

156789-

Main Pump Overload Relief Valve Main Relief Valve Main Relief Valve Steering Valve Steering Spool

101316171819-

Steering Cylinder Multiple Control Valve Lift Arm Cylinder Lift Arm Spool Bucket Cylinder Bucket Spool

21- Load Check Valve 24- Overload Relief Valve 25- Lift Arm Flow Rate Control Valve 27- Pump Control Valve 30- Neutral Circuit

T2-4-35

31- Parallel Circuit 32- Hydraulic Tank 41- Bleed-off Compensation Valve

SECTION 2 SYSTEM Group 4 Hydraulic System Pump Control Circuit

y Pump Control by Torque Control Solenoid Valve 1. Torque control solenoid valve (14) is activated by the signal from the Main Controller.

y Pump Delivery Flow Rate Control by Pump Control Pressure Pc1.

1. When not operating the lift arm and bucket, pressurized oil from main pump (8) flows through neutral circuit (11) in multiple control valve (3).

2. Pressurized oil from the accessory pump, which is regulated and supplied via unloader valve, is sent to regulator (7) in main pump (8) as torque control pressure X1.

2. Pump control valve (4) is provided in neutral circuit (11). The circuit for controlling the pump delivery flow rate is provided at front of orifice (10) in pump control valve (4).

3. Pressurized oil from main pump (8) is supplied to regulator (7) in main pump (8) through the circuit for controlling the pump delivery flow rate at front of orifice (10) as pump control pressure Pc1.

3. Regulator (7) controls the pump delivery flow rate in proportion to torque control pressure X1.

NOTE: Refer to Control System / Pump Control.

4. Regulator (7) controls the pump delivery flow rate in proportion to pump control pressure Pc1.

5. When flow rate of pressurized oil flowing through neutral circuit (11) increases, the pressure at front of orifice (10) increases.

6. Therefore, the pressure Pc1 increases and regulator (7) reduces the pump delivery flow rate.

7. Consequently, flow rate of pressurized oil flowing to multiple control valve (3) is reduced.

NOTE: Refer to COMPONENT OPERATION / Pump Device.

T2-4-36

SECTION 2 SYSTEM Group 4 Hydraulic System Pump Control Unit Diagram

95TNED-02-04-09

P2- From Unloader Valve (Pressurized Oil from Accessory Pump)

X1- Torque Control Pressure Pc1- Pump Control Pressure

34-

57-

Multiple Control Valve Pump Control Valve

Hydraulic Tank Regulator

8- Main Pump 10- Orifice

T2-4-37

11- Neutral Circuit 14- Torque Control Solenoid Valve

SECTION 2 SYSTEM Group 4 Hydraulic System Parallel Circuit Flow Rate Control Purpose: The parallel circuit flow rate control limits the flow rate of parallel circuit (31) according to work load. The oil flow to lift arm (boom) cylinders (16) is stopped to operate bucket cylinder (18) only (tandem operation).

NOTE: Pressure sensors (33) detects the pilot pressure to judge the current work load for parallel/tandem switching.

NOTE: The lift arm raise / bucket roll back when not operating the steering is explained here.

1. Pressurized oil from main pump (1) flows to lift arm cylinder (16) through lift arm flow rate control valve (25) of parallel circuit (31) in multiple control valve (13) when raising lift arms and rolling back the bucket. Pressurized oil from main pump (1) flows to bucket cylinder (18) at the same time.

2. When the conditions listed below for front attachment operation selection control exist, the Main Controller activates solenoid valve for parallel circuit flow rate control (SV1). (Refer to SYSTEM / Lift Arm and Bucket Selection Circuit Control.)

Conditions: x Combined operation of lift arm raise and bucket roll back or dump when the lift arm is raised beyond the specified position 3. Lift arm flow rate control valve (25) is shifted by pilot pressure oil (SY) from solenoid valve (SV1).

4. Pressurized oil flowing through parallel circuit (31) is restricted by lift arm flow rate control valve (25) and oil flow to lift arm cylinder (16) is reduced.

5. Therefore, oil flow to bucket cylinder (18) increases and the bucket operating speed also increases due to increased flow.

NOTE: This is used when the bucket is either dumped or rolled back while raising the lift arms.

T2-4-38

SECTION 2 SYSTEM Group 4 Hydraulic System Parallel Flow Circuit

95TNED-02-04-42

SY- From Parallel/Tandem Switching Solenoid Valve (SV1) (Pilot Pressure Oil) 1- Main Pump 13- Multiple Control Valve 16- Lift Arm Cylinder

18- Bucket Cylinder 25- Lift Arm Flow Rate Control Valve

31- Parallel Circuit 32- Hydraulic Tank

T2-4-39

33- Pressure Sensor (for Loading Pilot Pressure)

SECTION 2 SYSTEM Group 4 Hydraulic System Single Operation Circuit y Bucket Roll Back Operation

NOTE: The bucket roll back without operating the steering is explained here.

1. Pilot pressure oil (Pa1) shifts bucket spool (19) during bucket roll back. (Refer to Pilot Circuit, Lift Arm / Bucket Operation Control Circuit.)

2. Pressurized oil from main pump (1) flows to bucket spool (19) through multiple control valve (13), bleed-off compensation valve (41) and load check valve (21).

3. Pressurized oil flows through bucket spool (19), moves bucket cylinder (18), and rolls the bucket back.

4. Returning oil from bucket cylinder (18) returns to hydraulic tank (32) through bucket spool (19).

T2-4-40

SECTION 2 SYSTEM Group 4 Hydraulic System y Bucket Roll Back Operation

95TNED-02-04-22

Pa1- Bucket Roll Back (Pilot Pressurized Oil) 1- Main Pump 8- Steering Valve 13- Multiple Control Valve

18- Bucket Cylinder 19- Bucket Spool 21- Load Check Valve

32- Hydraulic Tank 41- Bleed-off Compensation Valve

T2-4-41

SECTION 2 SYSTEM Group 4 Hydraulic System Combined Operation Circuit 8. Pressurized oil from main pump (1) flows to parallel circuit (31) in multiple control valve (13) at the same time as described above so that combined operation of lift arm / bucket is made.

Combined Operation of Lift Arm Raise / Bucket Dump: Operating the lift arm and bucket circuit without steering is explained here.

NOTE: The flow rate of parallel circuit is limited

according to work load. The bucket operating speed is fast by reducing oil flow to the lift arm cylinder and increasing oil flow to the bucket cylinder. (Refer to Parallel Circuit Flow Rate Control.)

1. Pilot pressure oil (Pa2) shifts lift arm spool (17) during bucket dump with the lift arm raised. Pilot pressure oil (Pb1) shifts bucket spool (19) at the same time. (Refer to Pilot Circuit, Lift Arm / Bucket Operation Control Circuit.)

2. When not operating the joystick steering lever, oil flow from main pump (1) is supplied to multiple control valve (13) through bleed-off compensation valve (41). (Refer to Main Circuit, Steering Priority Circuit.)

3. Pressurized oil from main pump (1) is supplied to parallel circuit (31) in multiple control valve (13) and the bucket circuit.

4. Pressurized oil flowing to parallel circuit (31) flows to lift arm spool (17) through lift arm flow rate control valve (25) and raises the lift arm.

5. Returning oil from lift arm cylinder (16) returns to hydraulic oil tank (32) through lift arm spool (17).

6. Pressurized oil flows to bucket spool (19) through load check valve (21) in the bucket circuit at the same time and dumps the bucket.

7. Returning oil from bucket cylinder (18) returns to hydraulic oil tank (32) through bucket spool (19).

T2-4-42

SECTION 2 SYSTEM Group 4 Hydraulic System y Combined operation of lift arm raise / bucket dump

95TNED-02-04-41

Pb1- Bucket Dump (Pilot Pressurized Oil)

Pa2- Lift Arm Raise (Pilot Pressurized Oil)

181316-

17181921-

Main Pump Steering Valve Multiple Control Valve Lift Arm Cylinder

Lift Arm Spool Bucket Cylinder Bucket Spool Load Check Valve

25- Lift Arm Flow Rate Control Valve 31- Parallel Circuit 32- Hydraulic Tank

T2-4-43

SECTION 2 SYSTEM Group 4 Hydraulic System Combined Operation of Steering (Right) / Lift Arm Raise Operation of lift arm raise and steering (right) combined is explained here.

1. When shifting the joystick steering lever to the right with the lift arm raising, pilot pressure oil (Pa2) shifts lift arm spool (17) of control valve (13). Pilot pressure oil (Pb) shifts steering spool (9) in steering valve (8) at the same time.

2. When steering spool (9) shifts, the pressurized oil is supplied to bleed-off compensation valve (41) in multiple control valve (13) via port LS1. (Refer to Steering Priority Circuit.)

3. Bleed-off compensation valve (41) controls the pressurized oil amount in the steering circuit in proportion to the movement of steering spool (9) of steering valve (8). The excess oil is supplied to the loading circuit.

4. Pressurized oil in steering spool (9) moves steering cylinders (10, 11) at right and left and the machine turns right.

5. Pressurized oil from main pump (1) flows to lift arm spool (17) through lift arm flow rate control valve (25) of parallel circuit (31) in multiple control valve (13).

6. Pressurized oil in lift arm spool (17) moves lift arm cylinder (16) and raises the lift arm.

7. Therefore, steering (right) operation and lift arm raise operation are simultaneously made.

T2-4-44

SECTION 2 SYSTEM Group 4 Hydraulic System y Combined operation of steering right / lift arm raise

115TNED-02-04-43

Pb- Steering (Right) (Pilot Pressurized Oil)

Pa2- Lift Arm Raise (Pilot Pressurized Oil)

1891011-

1213141617-

Main Pump Steering Valve Steering Spool Steering Cylinder (Left) Steering Cylinder (Right)

Joystick Steering Control Valve Multiple Control Valve Steering Pilot Valve Lift Arm Cylinder Lift Arm Spool

25- Lift Arm Flow Rate Control Valve 31- Parallel Circuit 32- Hydraulic Tank 40- Meter-in Compensation Valve

T2-4-45

41- Bleed-off Compensation Valve

SECTION 2 SYSTEM Group 4 Hydraulic System Exhaust Filter Regeneration Control Circuit Purpose: A load is applied to the engine during manual or auto regeneration of the exhaust filter by increasing the load to the hydraulic pump. Therefore, the exhaust temperature is raised up to the temperature that a catalyst is able to be activated. y Valve Control by Exhaust Filter Manual or Auto Regeneration Control Pressure 1. When the conditions for exhaust filter manual or auto regeneration control exist, the Main Controller (MC) shifts selector valve (1) (SV2).

2. Pressurized oil from main pump (5) is then supplied to multiple control valve (2) via the Pls port.

3. Bleed-off compensation spool (3) (BS) blocks the flow to the loading circuit, and the pressure increases up to main relief valve (4) (MR) set pressure. The pressurized oil is drained to hydraulic tank (6).

4. Therefore, the load is applied to the engine by increasing the load to main pump (5).

5. Consequently, the engine exhaust temperature is raised and regeneration of the exhaust filter is possible. y Main Pump (5) Delivery Flow Rate Control by Exhaust Filter Manual or Auto Regeneration Control Pressure 1. When the selector valve (1) (SV2) shifts, pressurized oil from main pump (5) to multiple control valve (2) stops. Pump control pressure (Pc1) lowers and equals to the hydraulic tank pressure.

2. Regulator (7) in main pump (5) increases the delivery flow rate of main pump (5) when pump control pressure (Pc1) decreases.

NOTE: Refer to Control System / Exhaust Filter Manual Regeneration Control.

T2-4-46

SECTION 2 SYSTEM Group 4 Hydraulic System Exhaust Filter Regeneration Hydraulic Diagram

95TNED-02-04-13

12-

Selector Valve (SV2) Multiple Control Valve

34-

Bleed-off Compensation Spool (BS) Main Relief Valve (MR)

567-

T2-4-47

Main Pump Hydraulic Tank Pump Regulator

SECTION 2 SYSTEM Group 4 Hydraulic System 7. When fore and aft pitching of the loader results in pushing up on the lift arm base end circuit (a) pressure of lift arm cylinder (6) decreases.

Ride Control Circuit (Option) 1. When the conditions for ride control exist, MC shifts solenoid valves (SV1, SV2).

SV1 is a selector valve mounted on multiple control valve (2) on the rod side of the lift arm cylinder (6). SV2 is a proportional solenoid valve in the ride control valve (RC).

2. Base end circuit (a) of lift arm (boom) cylinder (6) is connected to ride control accumulator (5).

Rod side circuit (b) of lift arm cylinder (6) is connected to hydraulic tank (8).

3. When pushing downward on and pulling upward on the lift arm due to fore and aft pitching, the base end circuit (a) oil pressure in lift arm cylinder (6) will spike up and down.

4. Oil pressure variances are transmitted to base end circuit (a) of lift arm cylinder (6) through ride control valve (RC) spool (3) and absorbed by ride control accumulator (5).

5. Therefore, cycling pressures at bottom side circuit (a) of lift arm cylinder (6) are regulated.

8. Pressurized oil from ride control accumulator (5) is supplied to base end circuit (a) of lift arm cylinder (6).

9. Therefore, pressure decrease at base end circuit (a) of lift arm cylinder (6) is regulated.

10. In addition, pressurized oil in rod side circuit (b) of lift arm cylinder (6) returns to hydraulic tank (8) as the rod side circuit (b) pressure of lift arm cylinder (6) increases.

11. Ride control accumulator (5) controls the base end circuit (a) pressure of lift arm cylinder (6) as described above.

12. Consequently, the machine ride is much better since fore and aft pitching when operating on rough terrain by use of a dampening circuit in the lift arm cylinder.

NOTE: Refer to Control System / Ride Control.

6. The rod side circuit (b) of lift arm cylinder (6) is opened to tank, permitting the cylinder to keep from developing voids due to such previously described cycling.

T2-4-48

SECTION 2 SYSTEM Group 4 Hydraulic System Ride Control Circuit Diagram

95TNED-02-04-14

a-

Lift Arm (Boom) Cylinder Bottom Side Circuit

b-

Lift Arm Cylinder Rod Side Circuit

RC- Ride Control Valve

23-

Multiple Control Valve Ride Control Valve Spool

56-

Ride Control Accumulator Lift Arm Cylinder

78-

T2-4-49

Bucket Cylinder Hydraulic Tank

P2- Regulated Pressurized Oil from Accessory Pump

SECTION 2 SYSTEM Group 4 Hydraulic System Secondary Steering Circuit (Option) 1. When pressurized oil from main pump (12) becomes below the specified value due to the engine failure and traveling over 5 km/h (3.1 mph), steering pressure switch (5) is turned OFF. 2. The Main Controller activates secondary steering motor (8) according to the OFF signal of steering pressure switch (5).

NOTE: The operation limit time of secondary steering pump (9) is maximum 60 seconds.

NOTE: Refer to Control System / Secondary Steering Control.

3. Secondary steering pump (9) is activated by activating secondary steering motor (8).

4. Secondary steering pump (9) draws hydraulic oil from hydraulic tank (11) and delivers it to steering valve (3).

5. Steering valve (3) shifts steering spool (4) according to pressurized oil from Orbitrol (14).

6. Pressurized oil from secondary steering pump (9) is supplied to right and left steering cylinders (1, 2) by shifting steering spool (4).

7. Right and left steering cylinders (1, 2) are operated by pressurized oil from secondary steering pump (9) and the machine turns.

8. Check valve (6) keeps the pressure in the secondary steering circuit constant.

9. Relief valve (10) prevents the pressure in the circuit between secondary steering pump and steering valve from increasing over the set pressure when secondary steering pump (9) is operated.

T2-4-50

SECTION 2 SYSTEM Group 4 Hydraulic System Secondary Steering Circuit

115TNED-02-04-12

1234-

Steering Cylinder (Left) Steering Cylinder (Right) Steering Valve Steering Spool

5678-

Steering Pressure Switch Check Valve Secondary Steering Pump Unit Secondary Steering Motor

9101112-

T2-4-51

Secondary Steering Pump Relief Valve Hydraulic Tank Main Pump

13- Joystick Steering Control Valve 14- Joystick Steering Pilot Valve

SECTION 2 SYSTEM Group 4 Hydraulic System (Blank)

T2-4-52

SECTION 2 SYSTEM Group 5 Electrical System Outline The electrical circuit is generally divided into the main circuit, monitor circuit, steering column monitor circuit, accessory circuit, and control circuit. y Main Circuit: Operates the engine and the accessory related circuits. y Monitor Circuit: Displays the machine operating conditions. Consists of monitor controller, monitor, relays, and switches. y Column Monitor Circuit: Is operated during machine operation. Consists of head lights, turn signal lights, brake lights, and horn. y Accessory Circuit (Option): Operates the accessory circuit. Consists of the column display controller, relays, and switches. y Control Circuit: Controls the engine, pump, transmission, and loading control valve. Consists of the actuators such as solenoid valves, Main Controller (MC) (Man), MC (Sub), Engine Control Module (ECM), sensors, and switches.

(Refer to SYSTEM / Control System.)

T2-5-1

SECTION 2 SYSTEM Group 5 Electrical System Main Circuit The major functions and circuits in the main circuit are as follows. x Electric Power Circuit: Supplies all electric power to all electrical systems on the machine. {Key switch, Battery, Fuses (Fuse box, Fusible link)} x Controller Area Network (CAN) Circuit: Performs communication between each controller. x Accessory Circuit: Is operated when the key switch is in the ACC position. x Starting Circuit: Starts the engine.

(Key switch, Starter, Starter relay) x Charging Circuit: Supplies electric power to the batteries and charges them. {Alternator, (Regulator)} x Surge Voltage Prevention Circuit: Prevents the occurrence of surge voltage developed when stopping the engine.

(Load dump relay) x Pilot Shut-Off Circuit (Key switch: ON): Supplies pressurized oil from the pilot pump to the pilot valve by the pilot shut-off solenoid valve.

(Pilot shut-off solenoid valve, Front control lever lock switch) x Auto Idling Stop Circuit: Stops the engine automatically when the fixed conditions exist.

(Main Controller (MC)(Main), Auto idling stop relay, ACC cut relay, Key switch ON cut relay) x Engine Stop Circuit (Key switch: OFF): Stops the engine by using Engine Control Module (ECM). {MC (Main), ECM}

T2-5-2

SECTION 2 SYSTEM Group 5 Electrical System (Blank)

T2-5-3

SECTION 2 SYSTEM Group 5 Electrical System Electric Power Circuit (Key Switch: OFF) The battery (1) minus terminal is grounded to the chassis.

Current from the battery (1) plus terminal flows as shown below when key switch (4) is in the OFF position.

Battery (1)

Fusible Link A (3)

Key Switch (4) Terminal B Fuse Box B (5)

Terminal #11

Light Switch (19)

Terminal #12

Cab Light (20) Radio (Backup Power) (21)

Terminal #13

Auxiliary (Power) (22)

Terminal #4

Auxiliary (Power) (14)

Terminal #5

Flasher Unit (15) Hazard Light Switch (16) Horn (Power) (17)

Terminal #1

Load Dump Relay (6) Main Controller (Main) (Power) (7) Monitor Controller (Power) (8) Column Display Controller (Power) (9)

Terminal #2

Main Controller (Sub) (Power) (12)

Terminal #3

ECM (Power) (13)

T2-5-4

SECTION 2 SYSTEM Group 5 Electrical System

95TNED-02-05-01

123456-

Battery Battery Relay Fusible Link A Key Switch Fuse Box B Load Dump Relay

789-

Main Controller (MC)(Main) (Power) Monitor Controller (power) Column Display Controller (Power)

12- Main Controller (MC)(Sub) (Power) 13- ECM (Power) 14- Auxiliary (Power) 15- Flasher Unit 16- Hazard Light Switch

T2-5-5

17192021-

Horn (Power) Light Switch Cab Light Radio (Backup Power) (for JP, EU) 22- Auxiliary (Power)

SECTION 2 SYSTEM Group 5 Electrical System CAN Circuit CAN (Controller Area Network) is ISO Standards of the serial communication protocol.

Two networks (CAN bus (4)), CAN 1 (1) and CAN 2 (5) are equipped for this machine.

CAN 1 (1) is used for the engine control. CAN 2 (5) is used for the accessories.

CAN bus (4) consists of two harnesses, CAN-H (High) (2) and CAN-L (Low) (3).

Each controller judges the CAN bus (4) level due to potential difference between CAN-H (High) (2) and CAN-L (Low) (3).

Each controller arranges the CAN bus (4) level and sends the signal and data to other controllers.

In addition, termination resistors (120 Ω) (17) are installed to both ends of CAN bus (4).

T2-5-6

SECTION 2 SYSTEM Group 5 Electrical System 2 1 3 4 2 5 3 TDAA-02-05-001

95TNED-02-01-01

1234-

CAN 1 CAN-H (High) CAN-L (Low) CAN Bus

5789-

CAN 2 ECM (Engine Controller) MC (Main Controller) (Main) MC (Main Controller) (Sub)

11121314-

T2-5-7

Monitor Controller MP (Maintenance Pro) Dr. Air Conditioner Controller Column Display Controller

15- Monitor Control Unit 16- Information Control Unit 17- Termination Resistor (120 Ω)

SECTION 2 SYSTEM Group 5 Electrical System Accessory Circuit (Key Switch: ACC) 1. When key switch (4) is set to ACC position (5), terminal B is connected to terminal ACC (6) in key switch (4).

2. Current from terminal ACC (6) in key switch (4) flows to fuse #20 in fuse box B (8) through ACC cut relay (7).

3. The relay (R1) turns ON, and current makes radio (9) operable.

T2-5-8

SECTION 2 SYSTEM Group 5 Electrical System

95TNED-02-05-02

123-

Battery Battery Relay Fusible Link A

456-

Key Switch ACC Position Terminal ACC

789-

T2-5-9

ACC Cut Relay (Optional) Fuse Box B Radio

10- Dome Light

SECTION 2 SYSTEM Group 5 Electrical System Starting Circuit (Key Switch: START) y Forward/Reverse Lever and Switch at Neutral Position

NOTE: Even if key switch (4) is set to START position

(5) with forward/reverse switch (11) set in forward (F) position (23) or reverse (R) position (25), the starter motor does not rotate and the engine does not start.

(Refer to Neutral Engine Start Circuit.)

1. When key switch (4) is set to START position (5), terminal B is connected to terminal M (6) and terminal ST (7) in key switch (4).

2. Current from terminal M (6) excites battery relay (2) through key switch ON cut relay (9). Current from battery (1) is routed to terminal B of starter (18) and starter relay (17) through battery relay (2).

3. In addition, current from terminal M (6) in key switch (4) flows to fuse #11 in fuse box A (13) through key switch ON cut relay (9).

4. Current from fuse #11 in fuse box A (13) flows to column display controller (19), monitor controller (20), Main Controller (MC) (Main) (21), MC (Sub) (22), ECM (12) and Communication Terminal as a signal indicating that key switch (4) is in ON or START position (5).

9. Current from terminal M (6) of key switch (4) flows to ECM (12) terminal #134 IS-IGKEY through fuse #11 in fuse box A (13) and the ECM (12) main power is turned ON. 10. ECM (12) makes the engine starting condition.

11. At the same time, current from terminal ST (7) flows to starter relay (17) through neutral relay (15) and starter cut relay (16).

12. Current flows to the coil in starter relay (17) and starter relay (17) is turned ON. 13. Therefore, current flows to terminal C in starter (18) through starter relay (17).

14. Consequently, the relay in starter (18) is turned ON so that the starter motor rotates.

5. Current from fuse #10 in fuse box B (8) flows to neutral relay (15) in relay box B (B6).

6. When forward/reverse switch (11) is in neutral (N) position (24), current from neutral relay (15) does not flow to ground circuit. Then, neutral relay (15) is turned OFF. 7. Therefore, current from terminal ST (7) flows to terminal #100 IS-START in Engine Control Module (ECM) (12) through neutral relay (15).

8. When ECM (12) receives this signal, ECM (12) turns OFF starter cut relay (14).

T2-5-10

SECTION 2 SYSTEM Group 5 Electrical System

115TNED-02-05-03

1234567-

Battery Battery Relay Fusible Link A Key Switch START Position Terminal M Terminal ST

8911121314-

Fuse Box B Key Switch ON Cut Relay (Optional) Forward/Reverse Switch Engine Control Module (ECM) Fuse Box A ECM Main Relay

15161718192021-

T2-5-11

Neutral Relay Starter Cut Relay Starter Relay Starter Column Display Controller Monitor Controller Main Controller (MC) (Main)

22232425-

Main Controller (MC) (Sub) Forward (F) Position Neutral (N) Position Reverse (R) Position

SECTION 2 SYSTEM Group 5 Electrical System Neutral Engine Start Circuit Purpose: The engine does not start with forward/reverse switch (11) set in forward (F) position (23) or reverse (R) position (25). Therefore, the engine is protected from unexpectedly starting out.

1. When forward/reverse switch (11) is set in forward (F) position (23) or reverse (R) position (25), current from fuse #10 in fuse box B (8) flows to the coil in neutral relay (15) via forward/reverse switch (11), and flows to the ground.

2. Therefore, neutral relay (15) is turned ON. 3. When neutral relay (15) is turned ON, current from terminal ST (7) in key switch (4) stops flowing to starter relay (17).

4. Consequently, starter relay (17) is turned OFF. Even if key switch (4) is set to START position (5), the starter motor does not rotate and the engine does not start.

T2-5-12

SECTION 2 SYSTEM Group 5 Electrical System

115TNED-02-05-04

1234567-

Battery Battery Relay Fusible Link A Key Switch START Position Terminal M Terminal ST

8911121314-

Fuse Box B Key Switch ON Cut Relay (Optional) Forward/Reverse Switch Engine Control Module (ECM) Fuse Box A ECM Main Relay

15161718192021-

T2-5-13

Neutral Relay Starter Cut Relay Starter Relay Starter Column Display Controller Monitor Controller Main Controller (MC) (Main)

22232425-

Main Controller (MC) (Sub) Forward (F) Position Neutral (N) Position Reverse (R) Position

SECTION 2 SYSTEM Group 5 Electrical System Charging Circuit (Key Switch: ON) 1. After the engine starts and key switch (4) is released, key switch (4) is returned to the ON position.

2. Terminal B is connected to terminal ACC (7) and terminal M (8) in key switch (4) with key switch (4) set in the ON position.

3. Current from terminal M (8) turns ON battery relay (2) through key switch ON cut relay (9) and terminal #11 in fuse box A (13).

4. Alternator (5) starts generating electricity with the engine running. Current from alternator (5) terminal B flows to battery (1) through fuse 140 A (11) and battery relay (2), and charges battery (1).

5. In addition, current from alternator (5) terminal L flows to column display controller (19), and monitor controller (20).

6. Column display controller (19) detects the alternator (5) generating electricity according to current from alternator (5) and deletes the alternator alarm on monitor.

T2-5-14

SECTION 2 SYSTEM Group 5 Electrical System

95TNED-02-05-05

1234-

Battery Battery Relay Fusible Link A Key Switch

5789-

Alternator Terminal ACC Terminal M Key Switch ON Cut Relay (OPT)

13111920-

T2-5-15

Fuse Box A Main Fuse 140 A Column Display Controller Monitor Controller

SECTION 2 SYSTEM Group 5 Electrical System Alternator Operation 1. Alternator (3) consists of field coil FC, stator coil SC, and diodes D.

5. When current flows through field coil FC, the rotor is further magnetized so that the generating voltage increases. Thereby, current through field coil FC increases. Therefore, generating voltage increases further and battery (1) start charging.

2. The terminal M in the key switch is connected to regulator (4) through connector R. 3. When battery relay (2) is in the ON position, the battery (1) voltage is applied to regulator (4).

6. Monitor controller (5) detects the alternator voltage and turns ON/OFF the charge lamp.

4. At the beginning, no current is flowing through field coil FC. When the rotor starts rotating, alternate current is generated in stator coil SC due to the rotor remain magnetism.

95TDAA-02-05-04 12-

Battery Battery Relay

34-

Alternator Regulator

5-

T2-5-16

Monitor Controller

SECTION 2 SYSTEM Group 5 Electrical System (Blank)

T2-5-17

SECTION 2 SYSTEM Group 5 Electrical System Surge Voltage Prevention Circuit 1. When the engine is stopped (key switch (4): OFF), current from terminal M (8) in key switch (4) disappears and battery relay (2) is turned OFF. 2. The engine continues to rotate due to inertia force just after key switch (4) is turned OFF so that alternator (5) continues to generate electricity.

3. As the generating current cannot flow to battery (1), surge voltage arises in the circuit and failures of the electronic components, such as the controller, possibly cause. For this reason, the surge voltage prevention circuit is provided.

4. When alternator (5) is generating electricity, the generating current from alternator (5) terminal L flows to terminal #A15 of monitor controller (12).

Monitor controller (12) connects terminal #D8 to the ground.

5. Therefore, current flows to the exciting circuit in load dump relay (13) and load dump relay (13) is turned ON. 6. Consequently, even if key switch (4) is turned OFF with the engine running, current from battery (1) continues to excite battery relay (2) through load dump relay (13).

7. In addition, when a fixed time has passed since alternator (5) stops generating electricity, monitor controller (12) disconnect terminal #D8 from the ground. Therefore, battery relay (2) is turned OFF.

T2-5-18

SECTION 2 SYSTEM Group 5 Electrical System

95TNED-02-05-06

123-

Battery Battery Relay Fusible Link A

458-

Key Switch Alternator Terminal M

10- Fuse Box B 11- Main Fuse 140 A 12- Monitor Controller

T2-5-19

13- Load Dump Relay

SECTION 2 SYSTEM Group 5 Electrical System Pilot Shut-Off Circuit (Key Switch: ON) y Front Control Lever Lock Switch: OFF (Release) Position

y Front Control Lever Lock Switch: ON (Lock) Position 1. When the key switch is in the ON position, current from the battery relay flows to fuse #16 in fuse box B (3).

1. When front control lever lock switch (4) is set to OFF (release) position, the ground circuit in front control lever lock switch (4) is disconnected.

2. When front control lever lock switch (4) is in ON (lock) position, current from fuse #16 in fuse box B (3) flows to the coil in pilot shut-off relay (5), and connects to the ground in front control lever lock switch (4).

2. Therefore, pilot shut-off relay (5) is turned OFF.

3. Therefore, pilot shut-off relay (5) is turned ON.

4. Therefore, pressurized oil from the pilot pump is supplied to the pilot valve through pilot shut-off solenoid valve (6).

3. When pilot shut-off relay (5) is turned OFF, the power supply line to pilot shut-off solenoid valve (6) is connected and pilot shut-off solenoid valve (6) is turned ON.

4. When pilot shut-off relay (5) is turned ON, the power supply to pilot shut-off solenoid valve (6) is disconnected and pilot shut-off solenoid valve (6) is turned OFF. 5. Therefore, pressurized oil which flows to the pilot valve from the pilot pump is blocked by pilot shutoff solenoid valve (6).

6. Consequently, pressurized oil from the pilot pump is not supplied to the pilot valve. (Refer to Hydraulic System / Pilot Circuit.)

NOTE:

y When turning light switch (7) to TAIL, LO or HI position, work light relay turns on, and current from fuse #11 in fuse box B (3) turns on the backlight of front control lever lock switch (4) regardless of the control lever lock status. y MC (Sub) turns ON the control lever lock indicator on the monitor panel when the control lever lock works.

T2-5-20

SECTION 2 SYSTEM Group 5 Electrical System y Front Control Level Lock Switch (4): ON (Lock) Position

95TNED-02-05-07

y Front Control Level Lock Switch (4): OFF (Release) Position

95TNED-02-05-26

y Backlight Circuit of Front Control Level Lock Switch Light Switch (7)

Lock position Unlock position

115Z7-02-05-01

123-

Battery Relay Fuse Box A Fuse Box B

45-

Front Control Lever Lock Switch Pilot Shut-Off Relay

67-

T2-5-21

Pilot Shut-Off Solenoid Valve Light Switch

SECTION 2 SYSTEM Group 5 Electrical System Auto Idling Stop Circuit 1. When key switch (4) is in ON position, current from terminal M (5) excites battery relay (2) through key switch ON cut relay (8) and fuse #11 in fuse box A (7).

NOTE: Return key switch (4) to OFF position or the

2. In addition, current from terminal M (5) flows to the coils of auto idling stop relay (10), ACC cut relay (9), and key switch ON cut relay (8) through fuse #13 in fuse box A (7).

3. When all following conditions exist, Main Controller (MC) (Main) (11) connects terminal #B17 to the ground in it. (Refer to SYSTEM / Control System.)

4. Therefore, auto idling stop relay (10) is turned ON. ACC cut relay (9) and key switch ON cut relay (8) are also turned ON at the same time.

5. Current indicating that key switch (4) is in ON position stops flowing to terminal #134 IS-IGKEY of Engine Control Module (ECM) (12) through fuse #11 in fuse box A (7).

6. In addition, battery relay (2) is turned OFF at the same time.

7. Therefore, this is the same case when key switch (4) is set to OFF position. ECM (12) stops fuel injection of the injector and stops the engine.

8. When the engine stops, ECM (12) turns OFF ECM main relay (13).

Conditions: x Auto Idling Stop Setting: ON x Accelerator Pedal: Not applied x Parking Brake: Applied x Brake Pedal: Not applied x Forward/Reverse Lever, Forward/Reverse Switch: Neutral position x Front Attachment, Steering: Not operated x Auto Idling Stop: Effective (ON) x Overheat Alarm: OFF x Coolant Temperature: 95 ºC (203 ºF) or less x Hydraulic Oil Temperature: 95 ºC (203 ºF) or less x Torque Converter Oil Temperature: 115 ºC (239 ºF) or less x Except for exhaust filter manual regeneration x Communication between ECM and column display controller: Normal x Except for transmission learning x Engine: Running x Pump Delivery Pressure: 5.0 MPa (51 kgf/cm2, 725 psi) or less

T2-5-22

ACC position and reset it to the START position when restarting the engine.

SECTION 2 SYSTEM Group 5 Electrical System

95TNED-02-05-08

12345-

Battery Battery Relay Fusible Link A Key Switch Terminal M

6789-

Fuse Box B Fuse Box A Key Switch ON Cut Relay (Option) ACC Cut Relay (Option)

10111213-

T2-5-23

Auto Idling Stop Relay Main Controller (MC) (Main) Engine Control Module (ECM) ECM Main Relay

SECTION 2 SYSTEM Group 5 Electrical System Engine Stop Circuit 1. When key switch (4) is set to OFF position (16) from ON position (15), current indicating that key switch (4) is in ON position (15) stops flowing to terminal #134 IS-IGKEY of Engine Control Module (ECM) (12) from terminal M (5) in key switch (4).

2. ECM (12) stops fuel injection of the injector and stops the engine.

3. When the engine stops, ECM (12) turns OFF ECM main relay (13).

T2-5-24

SECTION 2 SYSTEM Group 5 Electrical System

95TNED-02-05-09

12345-

Battery Battery Relay Fusible Link A Key Switch Terminal M

6789-

Fuse Box B Fuse Box A Key Switch ON Cut Relay (Option) ACC Cut Relay (Option)

1011121315-

T2-5-25

Auto Idling Stop Relay Main Controller (MC) (Main) Engine Control Module (ECM) ECM Main Relay ON Position

16- OFF Position

SECTION 2 SYSTEM Group 5 Electrical System (Blank)

T2-5-26

SECTION 2 SYSTEM Group 5 Electrical System Monitor Circuit The major functions and circuits in the monitor circuit are as follows. x Air Conditioner Circuit: Operates the air conditioner.

(Monitor Controller, Switch Panel, Air Conditioner Unit)

T2-5-27

SECTION 2 SYSTEM Group 5 Electrical System Air Conditioner Circuit 1. The operation on switch panel (2) is displayed on monitor (1) through monitor controller (3).

2. When the setting for air conditioner is adjusted on switch panel (2), the signal is input to monitor controller (3).

3. Monitor controller (3) sends the signal to air conditioner unit (6) by using CAN communication (7) and air conditioner unit (6) operates.

T2-5-28

SECTION 2 SYSTEM Group 5 Electrical System

90TNED-02-05-10

123-

Monitor Switch Panel Monitor Controller

46-

Fuse Box A Air Conditioner Unit

7-

T2-5-29

Controller Area Network (CAN) 2

SECTION 2 SYSTEM Group 5 Electrical System (Blank)

T2-5-30

SECTION 2 SYSTEM Group 5 Electrical System Steering Column Monitor Circuit y Head Light Circuit: for turning on and off head lights, clearance lights, license lights, and tail lights. y Hazard Light Circuit: for turning on and off hazard lights. y Turn Signal Light Circuit: for turning on and off turn signal lights. y Horn Circuit: for sounding horn. y Reverse Light/Buzzer Circuit: for turning on and off reverse lights and reverse buzzer. y Brake Light Circuit: for turning on and off brake lights. y Parking Brake Circuit: for applying and releasing parking brake.

T2-5-31

SECTION 2 SYSTEM Group 5 Electrical System Head Light Circuit Clearance Light, Tail Light, License Light (Opt) Circuit (Light Switch: Tail ( | ) Position) 1. Current from the battery flows to light switch (2) through fuse #11 in fuse box B (1).

2. When light switch (2) is set to tail light position (21), the current turns on working lamp relay (20) through light switch (2), and current from fuse #11 in fuse box B (1) flows to fuses #1 and #2 in fuse box A (11).

3. Current from fuses #1 and #2 flows to clearance (width) lights (6, 9), tail lights (4, 7), and license lights (opt)(5), and connects to ground.

4. Therefore, clearance lights (6, 9), tail lights (4, 7), and license lights (5, 8) are turned on.

5. In addition, current from fuse #11 in fuse box B (1) flows to terminal #1-5 in column display controller (10) through working lamp relay (20).

6. Therefore, column display controller (10) turns on clearance light indicator (18).

T2-5-32

SECTION 2 SYSTEM Group 5 Electrical System

115TNED-02-05-11

124679-

Fuse Box B Light Switch Tail Light (Left) Clearance Light (Right) Tail Light (Right) Clearance Light (Left)

101112131415-

Column Display Controller Fuse Box A Head Light Relay (Left) Head Light Relay (Right) Head Light (Left) Head Light (Right)

161718192021-

T2-5-33

High Beam High-Beam Relay Clearance Light Indicator High-Beam Indicator Working Lamp Relay Tail Light Position

22- Low-Beam Position 23- High-Beam Position

SECTION 2 SYSTEM Group 5 Electrical System Head Light Circuit

NOTE: When light switch (2) is turned on with the head

The operation with light switch (2) set in low-beam position (22) is explained here.

1. When light switch (2) is set to head light (Lo) position (22), current from fuse #11 in fuse box B (1) flows to the coils in head light relays (right and left) (12, 13) through light switch (2), and connects to ground.

2. Therefore, head light relays (right and left) (12, 13) are turned ON. 3. When head light relays (right and left) (12, 13) are turned ON, current from fuses #7 in fuse box B (1) and #7 in fuse box A (11) flows to head lights (right and left) (14, 15) through head light relays (right and left) (12, 13), and connects to ground.

4. Therefore, head lights (right and left) (14, 15) turn on.

T2-5-34

lights on position (22, 23), head lights (14, 15), clearance lights (6, 9), tail lights (4, 7), and license lights (opt)(5) are turned on.

SECTION 2 SYSTEM Group 5 Electrical System

115TNED-02-05-12

124679-

Fuse Box B Light Switch Tail Light (Left) Clearance Light (Right) Tail Light (Right) Clearance Light (Left)

101112131415-

Column Display Controller Fuse Box A Head Light Relay (Left) Head Light Relay (Right) Head Light (Left) Head Light (Right)

161718192021-

T2-5-35

High Beam High-Beam Relay Clearance Light Indicator High-Beam Indicator Working Lamp Relay Tail Light Position

22- Low-Beam Position 23- High-Beam Position

SECTION 2 SYSTEM Group 5 Electrical System High-Beam Circuit

NOTE: When light switch (2) is turned on with the head

The operation with light switch (2) set in high-beam position (23) is explained here.

1. When light switch (2) is set to head light (Hi) position (23), current from fuse #11 in fuse box B (1) flows to the coil in high-beam relay (17) through light switch (2), and connects to ground.

2. Therefore, high-beam relay (17) is turned ON. 3. When high-beam relay (17) is turned ON, current from fuse #9 in fuse box A (11) flows to high beam (16) in head lights (right and left) (14, 15) through high-beam relay (17), and connects to ground.

4. Therefore, high beams (16) in head lights (14, 15) are turned on.

5. In addition, current from fuse #9 in fuse box A (11) flows to column display controller (10) terminal #1-3 through high-beam relay (17).

6. Therefore, column display controller (10) turns on high-beam indicator (19).

T2-5-36

lights on position (22, 23), head lights (14, 15), clearance lights (6, 9), tail lights (4, 7), and license lights (opt)(5) are turned on.

SECTION 2 SYSTEM Group 5 Electrical System

115TNED-02-05-13

124679-

Fuse Box B Light Switch Tail Light (Left) Clearance Light (Right) Tail Light (Right) Clearance Light (Left)

101112131415-

Column Display Controller Fuse Box A Head Light Relay (Left) Head Light Relay (Right) Head Light (Left) Head Light (Right)

161718192021-

T2-5-37

High Beam High-Beam Relay Clearance Light Indicator High-Beam Indicator Working Lamp Relay Tail Light Position

22- Low-Beam Position 23- High-Beam Position

SECTION 2 SYSTEM Group 5 Electrical System Hazard Light Circuit (Key Switch: OFF) 1. Current (a) from the battery flows to hazard light switch (3) and flasher relay (2) through fuse #5 in fuse box B (1), and connects to ground.

9. In addition, current from fuse #5 in fuse box B (1) flows to hazard light switch (3), and connects to ground.

2. Current from fuse #5 in fuse box B (1) flows to right and left turn signal light relays (4, 5) through hazard light switch (3).

10. Therefore, the indicator of hazard light switch (3) is turned on.

3. When hazard light switch (3) is set to the ON position, current from fuse #5 in fuse box B (1) flows to the coils in right and left turn signal light relays (4, 5) through hazard light switch (3), and connects to ground.

NOTE: The hazard light circuit can be activated even if

4. Therefore, right and left turn signal light relays (4, 5) are turned ON. 5. When right and left turn signal light relays (4, 5) are turned ON, current from flasher relay (2) terminal L flows to all turn signal lights (6, 7, 8, and 9) through right and left turn signal light relays (4, 5) intermittently, and connects to ground.

6. Therefore, all turn signal lights (6, 7, 8, and 9) blink.

7. At the same time, current from flasher relay (2) terminal L flows to terminals #1-1 and #1-4 in column display controller (10) intermittently.

8. Therefore, column display controller (10) blinks right and left turn signal indicators (18, 19).

T2-5-38

the key switch is in the OFF position.

SECTION 2 SYSTEM Group 5 Electrical System

90TNED-02-05-14

a-

From Battery

12345-

Fuse Box B Flasher Relay Hazard Light Switch Right Turn Signal Light Relay Left Turn Signal Light Relay

678910-

Turn Signal Light (Right Front) Turn Signal Light (Right Rear) Turn Signal Light (Left Front) Turn Signal Light (Left Rear) Column Display Controller

1112131415-

T2-5-39

Turn Signal Switch Left-Hand Position Neutral Position Right-Hand Position Diode R

16- Diode L 17- Fuse Box A 18- Right Turn Signal Light Indicator 19- Left Turn Signal Light Indicator

SECTION 2 SYSTEM Group 5 Electrical System Turn Signal Light Circuit

NOTE: The operation with turn signal switch (11) set in

9. At the same time, current from flasher relay (2) terminal L flows to terminal #1-4 in column display controller (10).

1. Current (a) from the battery flows to flasher relay (2) through fuse #5 in fuse box B (1), and connects to ground.

10. Therefore, column display controller (10) blinks left turn signal light indicator (19).

left turn position (L)(12) is explained here.

2. Current from flasher relay (2) terminal L flows to left turn signal light relay (5) and right turn signal light relay (4).

NOTE: When turn signal switch (11) is set in right turn

3. When the key switch is in the ON position, current from the battery flows to fuse #6 in fuse box A (17) through the battery relay and the main fuse (140 A).

4. Current from fuse #6 in fuse box A (17) flows to turn signal switch (11).

5. When turn signal switch (11) is set in left turn position (L)(12), current from fuse #6 in fuse box A (17) flows to the coil in left turn signal light relay (5) through turn signal switch (11) and diode K (16), and connects to ground.

6. Therefore, left turn signal light relay (5) is turned ON. 7. When turn signal light relay (5) is turned ON, current from flasher relay (2) terminal L flows to left turn signal lights (8 and 9) at front and rear through left turn signal light relay (5) intermittently, and connects to ground.

8. Therefore, left turn signal lights (8 and 9) at front and rear blink.

T2-5-40

position (R)(14), right turn signal lights (6 and 7) at front and rear blink. At the same time, column display controller (10) blinks right turn signal light indicator (18).

SECTION 2 SYSTEM Group 5 Electrical System

115TNED-02-05-15

a-

From Battery

12345-

Fuse Box B Flasher Relay Hazard Light Switch Right Turn Signal Light Relay Left Turn Signal Light Relay

678910-

Turn Signal Light (Right Front) Turn Signal Light (Right Rear) Turn Signal Light (Left Front) Turn Signal Light (Left Rear) Column Display Controller

1112131415-

T2-5-41

Turn Signal Switch Left-Hand Position Neutral Position Right-Hand Position Diode R

16- Diode L 17- Fuse Box A 18- Right Turn Signal Light Indicator 19- Left Turn Signal Light Indicator

SECTION 2 SYSTEM Group 5 Electrical System Horn Circuit (Key Switch: OFF) 1. Current (a) from the battery flows to horn relay (2) through fuse #5 in fuse box B (1).

2. When horn switches (3, 6) are pushed, current flowing to the coil in horn relay (2) connects to ground.

3. Therefore, horn relay (2) is turned ON. 4. When horn relay (2) is turned ON, current from fuse #5 in fuse box B (1) operates horns (4, 5).

NOTE: The horn circuit can be activated even if the key switch is in the OFF position.

T2-5-42

SECTION 2 SYSTEM Group 5 Electrical System

90TNED-02-05-16

a-

From Battery

12-

Fuse Box B Horn Relay

34-

Horn Switch Horn (HIGH)

56-

T2-5-43

Horn (LOW) Horn Switch (Side)

SECTION 2 SYSTEM Group 5 Electrical System Reverse Light/Buzzer Circuit 1. When the key switch is in the ON position, current from the battery flows to fuse #3 in fuse box A (1) through the battery relay and the main fuse (140 A).

2. Current from fuse #3 in fuse box A (1) flows to back buzzer relay (2).

3. Current from key switch terminal M flows to fuse #11 in fuse box A (1) through the key switch ON cut relay. Current from fuse #11 in fuse box A (1) flows to the coil in back buzzer relay (2), and flows to Main Controller (MC) (Main) (6) terminal #C17.

4. When forward/reverse switch (11) is set to reverse position (10), MC (Main) (6) terminal #D13 is detected.

5. Terminal #C17 is connected to ground in MC (10).

6. Therefore, back buzzer relay (2) is turned ON. 7. When back buzzer relay (2) is turned ON, current from fuse #3 in fuse box A (1) flows to reverse lights (4, 5) at both sides, and connects to ground.

8. Therefore, reverse lights (4, 5) at both sides are turned on.

9. At the same time, current from fuse #3 in fuse box A (1) operates back buzzer (3).

T2-5-44

SECTION 2 SYSTEM Group 5 Electrical System

115TNED-02-05-17

a-

From Battery Relay

123-

Fuse Box A Back Buzzer Relay Back Buzzer

456-

Reverse Light (Right) Reverse Light (Left) Main Controller (MC) (Main)

8- Forward Position 10- Reverse Position 11- Forward/Reverse Switch

T2-5-45

SECTION 2 SYSTEM Group 5 Electrical System Brake Light Circuit 1. When the key switch is in the ON position, current from the battery flows to fuse #3 in fuse box A (1) through the battery relay and the main fuse (140 A).

2. Current from fuse #3 in fuse box A (1) flows to brake light relay (2).

3. When the brake pedal is operated, brake light switch (5) is turned ON. 4. When brake light switch (5) is turned ON, current from fuse #3 in fuse box A (1) flows to the coil in brake light relay (2), and connects to ground.

5. Therefore, brake light relay (2) is turned ON. 6. When brake light relay (2) is turned ON, current from fuse #3 in fuse box A (1) flows to brake lights (3, 4) at both sides, and connects to ground.

7. Therefore, brake lights (3, 4) at both sides are turned on.

T2-5-46

SECTION 2 SYSTEM Group 5 Electrical System

115TNED-02-05-18

a-

From Battery Relay

12-

Fuse Box A Brake Light Relay

34-

Brake Light (Right) Brake Light (Left)

5-

T2-5-47

Brake Light Switch

SECTION 2 SYSTEM Group 5 Electrical System Parking Brake Circuit Parking Brake: Released (Parking Brake Switch: Release Position) IMPORTANT: The parking brake can be released only while the engine runs.

1. Terminal #A15 in monitor controller (1) receives voltage signal (beyond 13 V) (a) from alternator terminal L with the engine running. Terminal #D13 is disconnected from ground in monitor controller (1).

2. Therefore, parking brake relay 1 (2) is turned OFF. 3. When parking brake relay 1 (2) is turned OFF, current from fuse #11 in fuse box A (8) flows to terminal #4 in parking brake switch (3) through parking brake relay 1 (2) (supply side) and the coil in parking brake relay 2 (4).

4. When parking brake switch (3) is set to Release position, parking brake switch (3) connects terminal #4 to terminal #6 in it. In addition, terminal #6 is connected to ground.

9. Pressurized oil from the pilot pump (parking brake release pressurized oil) is supplied to the parking brake through parking brake solenoid valve (6).

10. Therefore, the spring of parking brake is pushed back and the parking brake is released.

11. When parking brake switch (3) with it set in Release position is released, it returns to Neutral position.

12. Therefore, current from terminal #4 in parking brake switch (3) stops flowing to terminal #6.

13. However, as the self-exciting circuit is formed in parking brake relay 2 (4), parking brake solenoid valve (6) continues to be operated.

14. Consequently, parking brake solenoid valve (6) continues to be operated until parking brake switch (3) is set to Apply position.

NOTE: Parking brake switch (3) is a three position

5. Therefore, parking brake relay 2 (4) is turned ON. 6. When parking brake relay 2 (4) is turned ON, current from fuse #15 in fuse box B (9) flows to ground through parking brake solenoid (6).

7. Therefore, parking brake solenoid valve (6) is activated.

8. At the same time, current from parking brake relay 2 (4) (coil) flows to parking brake relay 2 (4) (contact) through diode G (5), and the self-exciting circuit is formed.

T2-5-48

switch which has release position, neutral position, and apply position. When parking brake switch set in apply position, it stay in apply position. When parking brake switch (3) is set in release position and released, it returns to neutral position.

SECTION 2 SYSTEM Group 5 Electrical System

95TNED-02-05-19

123-

Monitor Controller Parking Brake Relay 1 Parking Brake Switch

456-

Parking Brake Relay 2 Diode G Parking Brake Solenoid Valve

789-

T2-5-49

Diode F Fuse Box A Fuse Box B

SECTION 2 SYSTEM Group 5 Electrical System Parking Brake: Applied (Parking Brake Switch: Apply Position)

NOTE: This parking brake system is spring applied,

1. Current from key switch terminal M flows to fuse #11 in fuse box A (8) through the key ON cut relay.

2. Current from fuse #11 in fuse box A (8) flows to the coil side of parking brake relay 1 (2), and flows to terminal #1 in parking brake switch (3).

3. When parking brake switch (3) is set to Apply position terminal #1 in parking brake switch (3) is connected to ground.

4. Therefore, parking brake relay 1 (2) is turned ON. 5. When parking brake relay 1 (2) is turned ON, current from parking brake relay 1 (2) (supply side) stops flowing to the coil of parking brake relay 2 (4).

6. Therefore, parking brake solenoid valve (6) ground circuit is disconnected.

7. Consequently, parking brake solenoid valve (6) is turned OFF. 8. Pressurized oil from the pilot pump (parking brake release pressurized oil) is blocked by parking brake solenoid valve (6). In addition, pressurized oil in the parking brake returns to the hydraulic tank.

9. Therefore, the parking brake is applied by the spring force.

T2-5-50

oil release type. As pressurized oil from the pilot pump (parking brake release pressurized oil) is not supplied to the parking brake with the engine stopped, the parking brake is applied by the spring force. Therefore, the parking brake can not be released with the engine stopped.

SECTION 2 SYSTEM Group 5 Electrical System

95TNED-02-05-20

123-

Monitor Controller Parking Brake Relay 1 Parking Brake Switch

456-

Parking Brake Relay 2 Diode G Parking Brake Solenoid Valve

789-

T2-5-51

Diode F Fuse Box A Fuse Box B

SECTION 2 SYSTEM Group 5 Electrical System (Blank)

T2-5-52

SECTION 2 SYSTEM Group 5 Electrical System Accessory Circuit The major functions and circuits in the accessory circuit are as follows. x Work Light Circuit: Turns on the work light.

(Work Light Switch, Work Light Relay) x Wiper Circuit: Operates the intermittent operation of wiper and the washer.

(Column Display Controller, Wiper/Washer Switch, Wiper Relay, Washer Relay) x Cab Light Circuit: Turns on/off the cab light by shifting the switch or by opening/closing the door.

T2-5-53

SECTION 2 SYSTEM Group 5 Electrical System Work Light Circuit

NOTE: Work lights (7, 8, 9, and 10) at front and rear can

NOTE: The operation with work light switch (4) set

be turned on when light switch (2) is set to position to turn on clearance lights (14) or head lights (15).

in ON 2 position (11) to turn front work light is ON is explained here.

1. When the key switch is in the ON position, current (b) from the battery flows to fuse #5 in fuse box A (3) and fuse #17 in fuse box B (1) through the battery relay and the main fuse (140 A).

NOTE: When work light switch (4) is set to ON 1 position

2. Current from fuse #5 in fuse box A (3) flows to work light (front) relay (5). In addition, current from fuse #17 in fuse box B (1) flows to work light (rear) relay (6).

3. When light switch (2) is set to position tail, Lo, or Hi (13, 14 or 15), current from fuse #11 in fuse box B (1) flows to terminal #1 and terminal #4 in work light switch (4).

4. When work light switch (4) is set to ON 2 position (11), current (a) from fuse #11 in fuse box B (1) flows to the coil in work light (front) relay (5) through terminal #3 in work light switch (4), and connects to ground.

5. Therefore, work light (front) relay (5) is turned ON. 6. When work light (front) relay (5) is turned ON, current from fuse #5 in fuse box A (3) turns on work light (front, right) (7) and work light (front, left) (8).

7. At the same time, current from fuse #5 in fuse box A (3) flows to terminal #1-2 in column display controller (17).

8. Therefore, column display controller (17) turns on work light indicator (16).

9. In addition, current (a) turns on working lamp relay (20) through light switch (2), and the current from fuse #11 in fuse box B (1) flows to terminal #8 in work light switch (4) and the switch illuminates.

T2-5-54

(12), work lights (7, 8, 9, and 10) at front and rear are turned on.

SECTION 2 SYSTEM Group 5 Electrical System

115TNED-02-05-21

a-

From Battery

b-

From Battery Relay

123456-

Fuse Box B Light Switch Fuse Box A Work Light Switch Work Light (Front) Relay Work Light (Rear) Relay

7891011-

Work Light (Front, Right) Work Light (Front, Left) Work Light (Rear, Right) Work Light (Rear, Left) Work Light Switch ON2 Position

12- Work Light Switch ON1 Position 13- Tail Light Position 14- Lo-Beam Position 15- Hi-Beam Position 16- Work Light Indicator

T2-5-55

17- Column Display Controller 20- Working Lamp Relay

SECTION 2 SYSTEM Group 5 Electrical System Wiper Circuit Front Wiper Circuit

NOTE: The operation with front wiper/washer switch (8) set in Intermittent (INT.) position (15) is explained here.

1. Current from fuse #8 in fuse box B (2) flows to terminal #2-23 in column display controller (14) through the coil in front wiper relay 1 (5).

2. When front wiper/washer switch (8) is set to INT. position (15), current from column display controller (14) terminal #2-13 flows to terminal #B through terminal #Sint in front wiper/washer switch (8), and connects to ground.

3. When terminal #2-13 is connected to ground, column display controller (14) connects terminal #2-23 to ground in it intermittently.

4. Therefore, front wiper relay 1 (5) is turned ON/OFF intermittently.

5. When front wiper relay 1 (5) is turned ON, current from fuse #8 in fuse box B (2) flows to front wiper relay 1 (5) through slow speed circuit (18) in front wiper motor (3), and connects to ground.

6. Therefore, the front wiper is operated at slow speed or intermittently.

T2-5-56

SECTION 2 SYSTEM Group 5 Electrical System

115TNED-02-05-22

12345-

Fuse Box A Fuse Box B Front Wiper Motor Front Wiper Relay 2 Front Wiper Relay 1

678910-

Front Washer Motor Front Washer Relay Front Wiper/Washer Switch Rear Wiper/Washer Switch Rear Wiper Motor

1112131415-

T2-5-57

Rear Washer Motor Rear Wiper Relay Rear Washer Relay Column Display Controller Intermittent (INT.) Position

16- LOW Position 17- Diode H 18- Slow Speed Circuit

SECTION 2 SYSTEM Group 5 Electrical System Rear Wiper Circuit

NOTE: The operation with rear wiper/washer switch (9) set in ON position (16) is explained here.

1. When rear wiper/washer switch (9) is set to ON position (16), current from fuse #8 in fuse box A (1) flows to terminal #S2 in rear wiper/washer switch (9) through the coil in rear wiper relay (12), and connects to ground via terminal #B in rear wiper / washer switch (9).

2. Therefore, rear wiper relay (12) is turned ON. 3. When rear wiper relay (12) is turned ON, current from fuse #8 in fuse box A (1) flows to rear wiper motor (10) and operates the rear wiper at slow speed.

T2-5-58

SECTION 2 SYSTEM Group 5 Electrical System

115TNED-02-05-23

12345-

Fuse Box A Fuse Box B Front Wiper Motor Front Wiper Relay 2 Front Wiper Relay 1

678910-

Front Washer Motor Front Washer Relay Front Wiper/Washer Switch Rear Wiper/Washer Switch Rear Wiper Motor

1112131415-

T2-5-59

Rear Washer Motor Rear Wiper Relay Rear Washer Relay Column Display Controller INT. Position

16- LOW Position 17- Diode H

SECTION 2 SYSTEM Group 5 Electrical System Washer Circuit

NOTE: The operation of front washer is explained here.

1. While front wiper/washer switch (8) is pushed, current from column display controller (14) terminal #2-16 flows to terminal #W in front wiper/washer switch (8) through diode H (17), bridges within switch (8) to terminal #B, and connects to ground.

2. Current from fuse #8 in fuse box B (2) flows to the coil in front washer relay (7), flows to terminal #W in front wiper/washer switch (8) through diode H (17), bridges within switch (8) to terminal #B, and connects to ground.

3. Therefore, front washer relay (7) is turned ON. 4. When front washer relay (7) is turned ON, current from fuse #8 in fuse box B (2) flows to front washer motor (6) and operates the front washer.

T2-5-60

SECTION 2 SYSTEM Group 5 Electrical System

115TNED-02-05-24

12345-

Fuse Box A Fuse Box B Front Wiper Motor Front Wiper Relay 2 Front Wiper Relay 1

678910-

Front Washer Motor Front Washer Relay Front Wiper/Washer Switch Rear Wiper/Washer Switch Rear Wiper Motor

1112131415-

T2-5-61

Rear Washer Motor Rear Wiper Relay Rear Washer Relay Column Display Controller INT. Position

16- LOW Position 17- Diode H

SECTION 2 SYSTEM Group 5 Electrical System Cab Light Circuit Cab Light Switch (4): Door Interlocking Position (5)

Rear Cab Light Switch (8): ON

1. When cab light switch (4) is set to door interlocking position (5), current from fuse #12 in fuse box B (1) flows to door open/close switch (3) through cab light (2).

1. When rear cab light switch (8) is set to the ON position, current from fuse #12 in fuse box B (1) flows to rear cab light (7), and connects to ground.

2. When the cab door is opened, door open/close switch (3) is turned ON and is connected to ground.

3. Therefore, current from fuse #12 in fuse box B (1) flows to door open/close switch (3) and turns on cab light (2).

4. When the cab door is shut, door open/close switch (3) is turned OFF and is disconnected from ground.

5. Therefore, cab light (2) is turned off.

6. Consequently, when cab light switch (4) is in door interlocking position (5), cab light (2) is turned on/ off by opening/closing the cab door.

NOTE: Cab light (2) is always on with cab light switch (4) set in ON position (6).

T2-5-62

2. Rear cab light (7) is always on with rear cab light switch (8) set in the ON position.

SECTION 2 SYSTEM Group 5 Electrical System

90TNED-02-05-25

12-

Fuse Box B Cab Light

34-

Door Open/Close Switch Cab Light Switch

56-

T2-5-63

Door Interlocking Position ON Position

78-

Rear Cab Light Rear Cab Light Switch

SECTION 2 SYSTEM Group 5 Electrical System (Blank)

T2-5-64

SECTION 3

COMPONENT OPERATION ―CONTENTS― Group 1

Pump Device

Group 4

Steering Pilot Valve

Hydraulic Pump Outline ............................T3-1-1

Steering Pilot Line.................................... T3-4-1

Main Hydraulic Pump ...............................T3-1-2

Unit Location ........................................... T3-4-2

Regulator .................................................T3-1-5

Steering Pilot Valve.................................. T3-4-4

Accessory Pump ......................................T3-1-8

Joystick Steering Control Valve ................ T3-4-6

Pump Delivery Pressure Sensor ............. T3-1-10

Group 5 Group 2

Control Valve

Steering Valve

Outline..................................................... T3-5-1

Outline .....................................................T3-2-1

Steering Valve Main Component .............. T3-5-2

Hydraulic Circuit .......................................T3-2-6

Operation ................................................ T3-5-4

Main Relief Valve......................................T3-2-8

Steering Valve Meter-In Compensator ...... T3-5-8

Overload Relief Valve

Steering Main Relief Valve ..................... T3-5-10

(with Make-Up Function) ..................... T3-2-10

Steering Overload Relief Valve............... T3-5-12

Bleed-Off Compensation Spool ............... T3-2-14

Steering Spool Variable Orifice............... T3-5-17

Bucket Spool .......................................... T3-2-16

Steering Pilot Circuit and Its Operation... T3-5-18

Lift Arm (Boom) Spool............................. T3-2-20

Flow Amplifier Notch and Pilot Orifice .... T3-5-20

Lift Arm Flow Rate Control Valve ............ T3-2-26 Ride Control (Option).............................. T3-2-28 Pump Control Valve (Negative Control Relief Valve)............ T3-2-30

Group 6

Pilot Valve

<Fingertip Control Type Pilot Valve > Outline..................................................... T3-6-1

Group 3

Cooling Fan System

Cooling Fan System Layout ......................T3-3-1 Fan Pump (Accessory Pump) ...................T3-3-1 Fan Motor.................................................T3-3-2 Fan Control Valve .....................................T3-3-3

Operation ................................................ T3-6-2 Electromagnetic Detent............................ T3-6-6 <Joystick Type Pilot Valve > Outline..................................................... T3-6-7 Operation ................................................ T3-6-9 Electromagnetic Detent.......................... T3-6-16

115Z7 F&S

Group 7

Charging Circuit

Group 9

Axle

Outline .....................................................T3-7-1

Outline..................................................... T3-9-1

Brake Charge Valve (Unloader Valve) .......T3-7-2

Front Axle Assembly ................................ T3-9-2

Combination Valve (Manifold Block)..........T3-7-4

Rear Axle Assembly ................................. T3-9-3

Combination Valve

Differential Gear (Conventional Type) ...... T3-9-6

(Solenoid Valve Block) ..........................T3-7-7

Limited Slip Differential (LSD) (Option) .. T3-9-12

Service Brake Accumulator.......................T3-7-9

Service Brake ........................................ T3-9-14 Parking Brake ........................................ T3-9-16

Group 8

Drive Unit

Parking Brake Manual Release .............. T3-9-17

Outline .....................................................T3-8-1 Transmission and Torque Converter Assy .T3-8-2 Drive Unit Hydraulic Circuit Diagram.........T3-8-3 Torque Converter (Lock-Up) .....................T3-8-4 Transmission ............................................T3-8-6 Cross Section View of Transmission .......T3-8-7 Operation of Transmission ........................T3-8-9

Group 10

Brake Valve

Outline................................................... T3-10-1 Brake Valve Component Layout ............. T3-10-2 Service Brake Operation ........................ T3-10-4 Auto Brake Operation ............................ T3-10-6

Clutch Pack ............................................ T3-8-11 Power Flow Path in the Transmission ..... T3-8-12

Group 11

Others

Transmission Control Valve .................... T3-8-18

Propeller Shaft........................................T3-11-1

Modulator Valve Unit ............................. T3-8-20

Secondary Steering Pump (Option) .........T3-11-5

Accumulator ........................................... T3-8-22

Flow Regulator Valve ..............................T3-11-6 Ride Control Valve ..................................T3-11-8 Ride Control Accumulator ..................... T3-11-12 Priority Hammer Valve .......................... T3-11-14

115Z7 F&S

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Hydraulic Pump Outline Hydraulic pump consists of main pump (1) and accessory pump (2). The driving force from the engine is transmitted to pump shaft through the input shaft of transmission (3) and activates these hydraulic pumps (1, 2).

Main pump (1) and accessory pump (2) are swash-plate type variable displacement axial piston pumps.

The hydraulic pump circuit is equipped with a torque control solenoid valve to control the pump output volume. (Refer to SYSTEM / Control System.)

2

4 3

1

115Z7-03-01-01 12-

Main Pump Accessory Pump

34-

Transmission Torque Converter

T3-1-1

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Main Hydraulic Pump When main pump cylinder block (1) rotates, piston (2) reciprocate in main pump cylinder block (1) due to angle of swash plate (4), and the pump draws the hydraulic oil up through the pump and delivers the oil out to the hydraulic systems.

Regulators (9) control servo piston 1 (3) and servo piston 2 (6). When the displacement angle of swash plate (4) is changed by servo piston1 (3) and servo piston 2 (6), the stroke of piston (2) is increased or decreased, so that the delivery flow rate of main pump is regulated.

The main hydraulic pump consists of coaxially-splined two swash plate type axial piston pumps.

The main hydraulic pump supplies pressurized oil for operating the steering and loading cylinders and other hydraulic components.

The pump is equipped with a regulator (9) for controlling the delivery flow rate.

Shaft (5) is connected to main pump cylinder block (1) so that shaft (5) and main pump cylinder block (1) rotate together.

Main Pump Hydraulic Diagram

90Z7-03-01-02

ab-

From Tank To Steering Line

c-

From Loading Line (Negative Control Relief Valve)

d-

To Loading Line (Bleed-Off Compensation Valve)

135-

Cylinder Block Servo Piston 1 Shaft

67-

Servo Piston 2 Pump Torque Control Solenoid Valve

9-

Regulator

T3-1-2

ef-

From Brake Line To Tank

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Main Pump Cross Section

90T4GB-03-01-02

123-

Cylinder Block Piston Servo Piston 1

456-

Swash Plate Shaft Servo Piston 2

78-

T3-1-3

Pump Torque Control Solenoid Valve Spherical Bush

9-

Regulator

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Increasing and Decreasing Flow Rate The displacement angle of swash plate (4) is changed by the movement of servo piston (3) as swash plate rotates around the center of spherical bush (8).

There are nine pistons in cylinder block (1) which reciprocate parallel to the rotating cylinder block axis.

During the rising portion of swash plate (4), piston (2) moves so as to protrude from cylinder block (1) and the oil draws in from the inlet port (suction: a).

While the falling portion of swash plate (4), piston (2) moves toward cylinder block (1) and the oil pushed through the outlet port (discharge: b).

When servo piston moves right, angle of swash plate (4) becomes great; the distance of piston movement increases, thus, oil flow rate increases.

When servo piston moves left, angle (α) of swash plate (4) becomes small; the distance of piston movement decreases, thus, oil flow rate decreases.

If swash plate angle (α) is zero, pistons do not stroke and oil does not flow.

Movement of the servo pistons is controlled by the regulators. In addition, the displacement angle of swash plate (4) is fed back to the regulator by feedback lever (7).

fNOTE: Refer to the following pages for operation of the regulator.

T3-1-4

90Z7-03-01-03

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Regulator The regulator controls the main pump flow rate in response to the various command signal pressures.

The major parts of regulator are spool, pistons, springs, sleeve, levers, and a solenoid reducing valve.

The regulator opens and closes the circuit leading to the servo piston according to the various command signal pressures.

The displacement angle of swash plate is changed and the pump flow rate is regulated.

Refer to the following pages for the regulator control functions.

90TNED-03-01-25

123-

Proportional Solenoid Valve (Reducing Valve) Pilot Piston Pilot Spring

4567-

Lever Feedback Lever Set Spring Return Spring

891011-

T3-1-5

Spool Sleeve Outer Spring Inner Spring

12- Compensation Piston 13- Compensation Rod 14- Servo Piston

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Regulator Control Function

90TNED-03-01-26 Fc- Pump Flow Control Valve (In Multiple Control Valve) Tc- Pump Torque Control Valve Pn- Pump Flow Control Pressure

Pt- Pump Torque Control Pressure P1- Main Pump 1 P2- Main Pump 2 Pp1- Pump 1 Delivery Pressure

8-

14- Servo Piston

Servo Piston Control Spool

Pp2- Pump 2 Delivery Pressure Ps1- Servo Piston Control Pressure (To Increase Flow Rate)

Ps2- Servo Piston Control Pressure (To Decrease Flow Rate) SF- Spring Force SC- Spool (8) Control Force

The regulator has the following three control functions.

Flow Control by Pump Control Pressure The pump flow rate control valve (Fc) in multiple control valve sends oil from the main pumps (P1, P2) to the main pump regulators as pump control pressure (Pn) in response to the control lever stroke.

The oil flows in the center bypass circuit. When the control lever is operated, pump control pressure (Pn) decreases as more oil goes to the cylinder circuit.

When control pressure (Pn) decreases, servo piston control spool (8) moves left by spring force (SF), and the pressure (Ps1) applied to servo piston (14) is higher than pressure (Ps2). Then, the regulator increases the pump delivery flow rate as swash plate tilting angle becomes greater.

Thus, when the pump flow control pressure (Pn) decreases, the pump delivery flow rate increases, and vise versa (negative flow control).

(Refer to SYSTEM / Hydraulic System.)

Q

0 Q-

T3-1-6

Flow Rate

Pn Pn- Pump Flow Control Pressure

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Control by Pilot Pressure from Torque Control Solenoid Valve MC (Main Controller) calculates the operating conditions of the machine and, using the calculation, the MC sends the pump torque control solenoid the appropriate signal for correct valve.

The torque control solenoid valve (Tc) delivers torque control pressure (Pt) to the regulator in response to this signal.

When this pressure (Pt) increases, the flow rate decreases limiting spool (8) movement to the left, thus prevents the servo piston control pressure (Ps2) from lowering to the minimum level. Also servo piston (14) movement to Ps2 side is limited and the maximum pump delivery flow rate decreases. (Torque Shift Control)

Maximum Torque Control Servo piston control spool (8) is operated by the resultant pressure FC (Pp1 + Pp2). (See the previous page) When the main pump delivery flow (input torque) is below the specified maximum level, the spring force (SF) exceeds the pressure force (FC) to operate servo piston spool (8), and the pump delivery flow rate can keep at the maximum.

When the main pump delivery flow (input torque) reaches the specified maximum level or more, the pressure force (FC) exceeds the spring force (SF) and moves servo piston spool (8) right to decrease the pump delivery flow rate.

90Z7-03-01-05a Q-

Flow Rate

P-

Pressure

90Z7-03-01-05b Q-

Flow Rate

P-

Pump Delivery Pressure

f NOTE: According to the rise of pump delivery pressure,

the tilting angle of swash plate automatically decreases, and the pump torque is controlled at a constant level.

90Z7-03-01-06

T3-1-7

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Accessory Pump Accessory pump is an open circuit axial piston pump with load sensing control, and is connected to the transmission assembly. Accessory pump supplies pilot pressurized oil to the brake circuit, fan motor circuit, and optional ride control circuit.

(Refer to "Pilot Circuit" in SYSTEM, Group 4 Hydraulic System.)

B

3

2

L1 B

M4

1 M4 1 S

Machine Front

S

M2 L2

X

L1

115Z7-03-01-02

SBX-

Inlet Port (Suction Line) Outlet Port (Main Pressure Line) LS Signal Port

L1- Case Drain Port L2- Case Drain Port M2- System Pressure Gauge Port (for Port B)

12-

Load Sensing (LS) Controller LS Standby Pressure Adjustment

3-

Pressure Compensator (PC) Pressure Adjustment

T3-1-8

M4- Gauge Port (Servo Pressure)

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Accessory Pump Structure and Function Port X

Input pressure System pressure

Load sense pressure 115Z7-03-01-04

1234-

Valve Plate Cylinder Block Spring Tapered Roller Bearing Cylinder Block

5678-

Servo Piston Bias Spring Piston Slipper

9101112-

Accessory pump has a single servo piston (5) with a cradle-type swash plate (11) set in polymer-coated journal bearings.

Bias spring (6) and internal forces increase swash plate angle. Servo piston (5) decreases swash plate angle.

Nine reciprocating pistons (7) displace fluid from the pump inlet to the pump outlet as the cylinder block rotates on pump input shaft (10).

Block spring (2) holds piston slippers (8) to swash plate (11) via slipper retainer (15).

Cylinder block (4) rides on a bi-metal valve plate (1) optimized for high volumetric efficiency and low noise.

Tapered roller bearings (3) support input shaft (10) and a lip-seal (9) protects against shaft leaks.

An adjustable two spool (LS and PC)(13, 14) control senses system pressure and load pressure (LS controls).

The control ports system pressure to the servo piston to control pump output flow.

T3-1-9

Shaft Seal Input Shaft Swash Plate Load Sensing (LS) Control

13- LS Spool 14- Pressure Compensator (PC) Spool 15- Slipper Retainer

SECTION 3 COMPONENT OPERATION Group 1 Pump Device Pump Delivery Pressure Sensor This sensor detects the pump delivery pressures, which are used in order to control various operations. When oil pressure is applied to diaphragm (6), diaphragm (6) flexes slightly. The flexing of diaphragm (6) is detected as electrical signals in ohms.

3-

Ground

5-

Power Source (5V)

4-

Output

6-

Pressure Receiving Area (Diaphragm) 90T157-02-03-10

T3-1-10

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Outline The multiple control valve controls the oil pressure, flow rate, and flow direction in the hydraulic circuit.

The major parts are the main relief valve, overload relief/ make-up combination valve, flow rate control valve, pump control valve, and spools. The spools are operated by pilot oil pressure.

Multiple Control Valve Location 1 2

Front Chassis

115TNED-03-02-03

12-

Lift Arm (Boom) Spool Bucket Spool

T3-2-1

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Multiple Control Valve Hydraulic Circuit

95TNED-03-02-10

1234-

Pump Control Valve Lift Arm Spool Lift Arm Flow Rate Control Valve (Selector Valve) Lift Arm Flow Rate Control Valve (Poppet Valve)

7-

89-

Overload Relief / Make-up Combination Valve (Lift Arm: Rod Side) Bucket Spool Load Check Valve (Bucket Tandem Circuit)

12- Overload Relief / Make-up Combination Valve (Bucket: Bottom Side) 13- Overload Relief / Make-up Combination Valve (Bucket: Rod Side)

T3-2-2

14- Main Relief Valve 15- Bleed-Off Compensator 16- Ride Control Selector Valve (Option)

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Control Valve Overview

95Z7-03-02-01

1234-

Pump Control Valve Lift Arm Spool Lift Arm Flow Rate Control Valve (Selector Valve) Lift Arm Flow Rate Control Valve (Poppet Valve)

7-

8-

Overload Relief / Make-up Combination Valve (Lift Arm: Rod Side) Bucket Spool

12- Overload Relief / Make-up Combination Valve (Bucket: Bottom Side) 13- Overload Relief / Make-up Combination Valve (Bucket: Rod Side)

T3-2-3

14- Main Relief Valve 15- Bleed-Off Compensator 16- Ride Control Selector Valve (Option)

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Control Valve Cross Section Views

95Z7-03-02-03

128-

Pump Control Valve Lift Arm Spool Bucket Spool

14- Main Relief Valve 15- Bleed-Off Compensator 17- Negative Control Relief Valve

T3-2-4

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Control Valve Cross Section Views

95Z7-03-02-02

2348-

Lift Arm Spool Lift Arm Flow Rate Control Valve (Selector Valve) Lift Arm Flow Rate Control Valve (Poppet Valve) Bucket Spool

9-

Load Check Valve (Bucket Tandem Circuit) 12- Overload Relief / Make-up Combination Valve (Bucket: Bottom Side)

13- Overload Relief / Make-up Combination Valve (Bucket: Rod Side) 16- Ride Control Selector Valve (Option)

T3-2-5

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Hydraulic Circuit Main Circuit Pressurized oil from pump (8) flows to the hydraulic oil tank through neutral circuit (11).

Parallel circuit (10) is provided in the hydraulic loading valve main circuit and makes possible the simultaneous combining of lift arm and bucket operation.

Pump control valve (1) is provided in the farthest downstream side of neutral circuit (11). Pump control valve (1) delivers pump control pressure to the hydraulic piston pump regulator in response to operation of the loading main control valve, and controls pump delivery flow rate.

Main relief valve (9) is provided in the main circuit (between the pump and the actuator (cylinder) spools within the valve). Main relief valve (9) prevents the pressure in the main circuit from exceeding the set pressure when the spool is operated (or when the control lever is operated).

Overload relief valve (2) is provided in the actuator (cylinder) circuit (between the control valve and the actuator (cylinder)) of the lift arm cylinder base end, bucket, and auxiliary. Overload relief valve (2) prevents pressure spikes caused by external forces in the actuator circuit from exceeding the set pressure when the spool is in neutral (with the control lever set in neutral).

Make-up valves (4, 6, 7) are provided in overload relief valves (2), which are located in the bucket cylinder circuit on both the rod and bottom sides, and in the lift arm cylinder circuit on rod side. Make-up valves (4, 6, 7) draw in pressurized oil from the hydraulic tank and prevent cavitation from occurring when the pressure in the actuator circuit decreases due to fast lowering of the lift arms or quick dumping of the bucket. It can also prevent cavitation when there is an external force causing oil to be relieved over the overload relief valves, which results in the opposing end of the cylinder drawing in oil to fill that end of the cylinder with.

T3-2-6

SECTION 3 COMPONENT OPERATION Group 2 Control Valve

95TNED-03-02-11

123-

Pump Control Valve Overload Relief Valve Lift Arm Cylinder

456-

Make-Up Valve Bucket Cylinder Make-Up Valve

789-

T3-2-7

Make-Up Valve Pump Main Relief Valve

10- Parallel Circuit 11- Neutral Circuit

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Main Relief Valve The main relief valve is installed between the pump and the bleed-off compensation spool.

The main relief valve prevents the pressure in the main circuit from exceeding the set pressure by discharging the oil from pump into hydraulic tank.

Therefore, circuit components, such as hoses, pipes and breakage other parts are protected from overpressure damage.

Relief Operation When the oil pressure is at the set point or below: 1. Pressurized oil from the pump is routed to chamber (10) through orifice (2) in main plunger (1).

2. Main plunger (1) is pressed against seat A (3) by the spring B (6) force.

3. Oil in chamber (10) acts on relief poppet (8). The spring A (9) force to relief poppet (8) right side is stronger, so relief poppet (8) and plunger (1) remain closed preventing any oil from escaping to tank.

When the oil pressure exceeds the set point: 1. When pressure applied to poppet (8) reaches the set pressure of spring B (6), poppet (8) is moved to the right and opens the port.

2. The pressurized oil from passage A (5) flows along the external circumference of seat B (4), and flows to port T (hydraulic tank).

3. As a result, the pressure in chamber (10) rapidly lowers and plunger (1) is moved to the right.

4. Then plunger (1) opens port T to the tank and pressurized oil in pump port P escapes to tank via port T.

fNOTE: This is a pilot operated relief valve type, which has the characteristic of keeping consistent pressure levels at varied rates of flow.

T3-2-8

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Main Relief Valve Operation During Normal Operation:

95TNED-03-02-13

During Relief Operation:

95TNED-03-02-14

P-

From Pump

T-

To Hydraulic Tank

123-

Main Plunger Orifice Seat A

456-

Seat B Passage A Spring B

8- Poppet 9- Spring A 10- Chamber

T3-2-9

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Overload Relief Valve (with Make-Up Function) An overload relief valve is located on both the rod and bottom sides of the bucket circuit, and on the rod side of the lift arm (boom) circuits.

The overload relief valve is installed in the circuit between the cylinder and the control valve spool.

When the spool is in the neutral position, if external force on the cylinder becomes too high and the oil pressure will be greatly increased, the overload relief valve returns the oil to the hydraulic tank to protect the cylinders and pipes from breakage.

Relief Operation When the oil pressure is at the preset value or less: 1. Pressurized oil in the cylinder in port CL (actuator circuit) is routed to chamber (2) through hole (1) of piston (3).

2. Plunger (6) is pressed against the spool by the spring A (4) force. Seat (5) is pressed by the pressure area difference between the cylinder port and chamber (2), so as to prevent any oil from escaping to the hydraulic tank.

When the oil pressure exceeds the preset value: 1. When pressure in the cylinder line reaches the set pressure of spring A (4), poppet (8) is moved to the right and opens the port.

2. The pressurized oil in chamber (2) flows along the external circumference of seat (5) to port T (hydraulic tank).

3. As a result, the pressure in chamber (2) rapidly lowers and plunger (6) is moved to the right.

4. Plunger (6) opens port T to the tank and pressurized oil in the cylinder port CL escapes to tank via port T.

T3-2-10

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Overload Relief Valve Operation During Normal Operation:

90TNED-03-02-15

During Relief Operation:

90TNED-03-02-16

CL- Cylinder Circuit

T-

To Hydraulic Tank

123-

456-

Spring A Seat Plunger

Hole Chamber Piston

78-

T3-2-11

Spring B Poppet

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Overload Relief Valve Make-Up Operation 1. When pressure in cylinder port CL (actuator circuit) decreases lower than pressure in port T (hydraulic tank), seat (5) is moved to the right by the pressure area difference of seat (5) between the right and left (X-Y).

2. Seat (5) opens the port and the oil in port T flows to port CL preventing a vacuum (negative pressure) in the cylinder.

T3-2-12

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Make-up Valve Operation

90TNED-03-02-17

CL- Cylinder Circuit 5-

T-

To Hydraulic Tank

Seat

T3-2-13

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Bleed-Off Compensation Spool The bleed-off compensator is provided in the pilot circuit, and controls oil flow supplied to the loading circuit.

Operation 1. When spool (2) is in neutral, spool (2) closes the oil passage to the loading line by spring (4) force.

2. After starting the engine, when the oil pressure in the main pump circuit (via main relief valve (3)) rises above the pressure set by spring (4), spool (2) is shifted to the left and opens the port to the loading circuit.

3. When the oil pressure in the Pls port increases, spool (2) is moved to the position where the pressure in the main pump circuit balances with the Pls port pressure + spring (4) force.

The port to the loading circuit is narrowed and the flow rate of pressurized oil flowing to steering valve (6) from main pump (1) increases.

Loading Line

95Z7-03-02-04

1234-

Main Pump Bleed-Off Compensation Spool Main Relief Valve Spring

567-

Multiple Control Valve Steering Valve Hydraulic Tank

T3-2-14

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Bleed-Off Compensator Neutral:

95Z7-03-02-05

When Activated:

95Z7-03-02-06

12-

Main Pump Bleed-Off Compensation Spool

34-

Main Relief Valve Spring

T3-2-15

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Bucket Spool Bucket Roll Back Operation 1. When the control lever is set to the "Bucket Roll Back" position, the pilot pressure is applied on the right oil pack (a1), spool (1) moves to the left, and spool shoulder (C) closes center bypass line (3).

2. As a result, the oil from the pump opens load check valve (2), flows from the A11 and A12 ports into the bottom side of bucket cylinders (4), and finally rolls back the bucket.

3. On the other hand, the oil on the rod side of bucket cylinders (4) returns from the B11 and B12 ports to hydraulic tank (7).

T3-2-16

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Bucket Spool Roll Back Operation

95Z7-03-02-07

95Z7-03-02-08

123-

Bucket Spool Load Check Valve Center Bypass Circuit

45-

Bucket Cylinder Overload Relief Valve with Make-Up Function

6-

T3-2-17

Overload Relief Valve with Make-Up Function

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Bucket Dump Operation 1. When the control lever is set to the "Bucket Dump" position, the pilot pressure is applied on the left oil pack (b1), spool (1) moves to the right, and spool shoulder (C) closes center bypass line (3).

2. As a result, the oil from the pump opens load check valve (2), flows from the B11 and B12 ports into the rod side of bucket cylinders (4), and finally dumps the bucket.

3. On the other hand, the oil on the bottom side of bucket cylinders (4) returns from the A11 and A12 ports to hydraulic tank (7).

4. Extremely quick dumping generates negative pressure (or a void) on the rod side. To prevent generation of negative pressure (or a void), makeup valve (5) opens so that the oil in the tank port flows into the rod side of the cylinder.

T3-2-18

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Bucket Spool Dump Operation

95Z7-03-02-15

95Z7-03-02-09

123-

Bucket Spool Load Check Valve Center Bypass Circuit

45-

Bucket Cylinder Overload Relief Valve with Make-Up Function

6-

T3-2-19

Overload Relief Valve with Make-Up Function

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Lift Arm (Boom) Spool Lift Arm (Boom) Raise Operation 1. When the control lever is set to the "Boom Raise" position, the pilot pressure is applied on the right oil pack (a2), spool (1) moves to the left, and spool shoulder (C) closes center bypass line (3).

2. As a result, the oil from the pump opens flow control valve poppet (2), flows from the A21 and A22 ports into the bottom side of boom cylinder (4), and finally raises the boom.

3. On the other hand, the oil on the rod side of boom cylinder (4) returns from the B21 and B22 ports to hydraulic tank (7).

T3-2-20

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Lift Arm (Boom) Spool Raise Operation

95Z7-03-02-10

95Z7-03-02-11

12-

Lift Arm (Boom) Spool Flow Control Valve Poppet

34-

Center Bypass Circuit Lift Arm (Boom) Cylinder

6-

T3-2-21

Ride Control Selector Valve (Option)

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Lift Arm (Boom) Down Operation 1. When the control lever is set to the "Boom Down" position, the pilot pressure is applied on the left oil pack (b2), spool (1) moves to the right, and spool shoulder (C) closes center bypass line (3).

2. As a result, the oil from the pump opens flow control valve poppet (2), flows from the B21 and B22 ports into the rod side of boom cylinder, (4) and finally moves down the boom.

3. On the other hand, the oil on the bottom side of boom cylinder (4) returns from the A21 and A22 ports to hydraulic tank (7).

4. Extremely quick lowering of the boom while the engine (pump) revolution is low generates negative pressure (or a void) on the rod side of the cylinder.

To prevent generation of negative pressure (or a void), make-up valve (5) opens so that the oil in the hydraulic tank port flows into the rod side of the cylinder.

T3-2-22

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Lift Arm (Boom) Down Operation

95Z7-03-02-16

95Z7-03-02-12

12-

Lift Arm (Boom) Spool Flow Control Valve Poppet

34-

Center Bypass Circuit Lift Arm (Boom) Cylinder

6-

T3-2-23

Ride Control Selector Valve (Option)

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Lift Arm (Boom) Float Operation 1. When the control lever is pushed downward beyond the "Boom Down" position to the "Boom Float" position, spool (1) moves fully to the right by the pressure oil from the b2.

2. As a result of this, all ports (i.e., pump port, cylinder rod end port and cylinder bottom end port) are connected to the tank port.

3. Therefore, the boom cylinder piston is not held by the oil pressure force any more and can move freely up and down by external force, which is useful for leveling uneven ground.

T3-2-24

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Lift Arm (Boom) Spool Float Operation

95Z7-03-02-13

95Z7-03-02-14 12-

Lift Arm (Boom) Spool Flow Control Valve Poppet

34-

Center Bypass Circuit Lift Arm (Boom) Cylinder

6-

T3-2-25

Ride Control Selector Valve (Option)

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Lift Arm Flow Rate Control Valve The flow rate control valve is provided between the lift arm (boom) spool and the parallel circuit, restricts oil flow rate in the circuit during combined operation of lift arm raise and bucket, and gives priority to the bucket.

Flow Rate Control Operation 1. Selector valve (2) of the lift arm flow rate control valve is shifted by pilot pressure from the parallel/ tandem switching valve via port PL. Low load High load

2. When no pressure is applied to the port PL, spool (7) in selector valve (2) positions in the neutral position.

Chamber B and chamber C, which is connected to the spring chamber D in poppet valve (3), are connected.

The pressurized oil from pump (5) via parallel circuit (4) flows through poppet valve (3) and selector valve (2) to lift arm spool (6).

During high load operation, poppet valve (3) moves up and more oil from parallel circuit (4) flows to lift arm spool (6).

95Z7-03-02-17

3. When pilot pressure is applied to the port PL (P), spool (7) moves to closes the passage between chamber B and chamber C, then the flow between selector valve (2) and poppet valve (3) is blocked.

Poppet valve (3) does not move and the oil from parallel circuit (4) does not flow to lift arm spool (6).

95Z7-03-02-18

P-

Pilot Pressure from Parallel/ Tandem Switching Valve

123-

Lift Arm Cylinder Selector Valve Poppet Valve

T3-2-26

456-

Parallel Circuit Pump Lift Arm Spool

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Normal Operation: (During Low Load)

(During High Load)

95TDCD-03-03-13

When Pressure Is Applied to PL Port:

95TDCD-03-03-15

a-

Pressurized Oil from Pump via Parallel Circuit

2-

Selector Valve

3-

b-

Oil Flow To Lift Arm Spool

Poppet Valve

7-

T3-2-27

Spool

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Ride Control (Option) The ride control reduces fore and aft pitching of the machine by permitting the base end of the lift arm cylinders to work the oil against a piston inside a nitrogen gas oil accumulator. Therefore, operator fatigue is reduced. In addition, the material spillage from the bucket is reduced. (Refer to SYSTEM / Control System.)

When the conditions for ride control exist, the Main Controller (Sub) shifts ride control selector (1).

The ride control selector is a switching solenoid valve mounted on multiple control valve (2) on the rod end of lift arm cylinder (3).

Ride Control Valve Unit

When this valve is energized (ride control is activated), the ports B21 and B22 connect to the tank port.

The multiple control valve port A23 is connected to the ride control valve unit. Refer to Group 11 Others for the operation of the ride control valve.

95TNED-03-02-29

T3-2-28

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Ride Control Selector Valve

95TNED-03-02-27

4-

Solenoid Valve

5-

Logic Valve

6-

T3-2-29

Solenoid Coil

SECTION 3 COMPONENT OPERATION Group 2 Control Valve Pump Control Valve (Negative Control Relief Valve) The pump control valve is provided in the farthest downstream side of neutral circuit (3), which is an opencenter circuit. The pump control valve discharges the pressurized oil to the tank in response to the operation of the loading control valve, and controls pump delivery flow rate. (Refer to SYSTEM / Hydraulic System.)

Operation: When the pressure in chamber P is at the set pressure of spring (1) or lower, the pressurized oil from the pump in the neutral circuit (in chamber P) flows to the tank circuit (chamber T) through orifice (2).

95Z7-03-02-19

When pressure in chamber P reaches the set pressure of spring (1), poppet (3) moves to the left, and the oil in chamber P flows to chamber T through the external circumference of poppet (3). The discharged oil amount to the tank increases, meanwhile the pump delivery flow rate is decreased.

95TNED-03-02-18

12-

T3-2-30

Spring Orifice

3-

Poppet

SECTION 3 COMPONENT OPERATION Group 2 Control Valve

95TNED-03-02-30

a-

To Main Pump Regulator

12-

Orifice Poppet

34-

Neutral Circuit Multiple Control Valve

56-

T3-2-31

Main Pump Hydraulic Tank

SECTION 3 COMPONENT OPERATION Group 2 Control Valve (Blank)

T3-2-32

SECTION 3 COMPONENT OPERATION Group 3 Cooling Fan System Cooling Fan System Layout 2

6 1

2

A-A 5

3

1

4

115Z7-03-03-01

12-

Fan Motor Fan Control Valve

34-

Priority Valve Drain Block

56-

Fan Pump (Accessory Pump) The accessory pump, a piston pump, supplies pressurized oil to the fan motor and fan valve.

Refer to "Accessory Pump" in Group 1 Pump Device.)

T3-3-1

Radiator Assembly To Oil Cooler

SECTION 3 COMPONENT OPERATION Group 3 Cooling Fan System Fan Motor The fan motor is a fixed displacement swash plate type axial piston motor.

Pressurized oil is supplied from the accessory pump into cylinder block (1) through valve plate (2). This pushes pistons (3) and generates the force to push plate (4) fixed at a certain angle for drive shaft (5). The end of shaft (5) is connected to the fan so the rotation of shaft (5) is transmitted to the fan.

95TDAB-03-07-01

12-

Cylinder Block Valve Plate

34-

Piston Cam Plate

56-

T3-3-2

Drive Shaft Retainer

SECTION 3 COMPONENT OPERATION Group 3 Cooling Fan System Fan Control Valve The fan control valve consists of fan reverse rotation control solenoid valve (1), fan reverse rotation spool (2), anti-void valve (3), and fan speed control relief valve (4).

Fan speed control solenoid valve (4) is shifted by the signals from the Main Controller (MC) (Sub) according to various sensor signals to rotate the fan at the best speed.

(Refer to SYSTEM / Control System / Fan Speed Control.)

Fan speed is load-sensing controlled. The accessory pump regulator detects the difference between the pump delivery pressure and the LS control pressure from the fan valve, and controls the delivery amount of pressurized oil according to this pressure difference. This enables to supply an appropriate amount of pressurized oil for each fan motor operation and minimize power losses.

The fan can rotate at the best speed matching the load requirements.

When the fan reverse rotation switch is turned ON, fan reverse rotation control solenoid valve (1) is shifted by the signals from MC (Sub). Fan reverse rotation spool (2) is shifted and the fan rotates in reverse.

(Refer to SYSTEM / Control System / Fan Reverse Rotation Control, SYSTEM / Hydraulic System / Fan Circuit.)

95TNED-03-03-01 PT

Pump Port Tank Port

P'

Pump Pressure Test Port

LS

Load-Sensing Pressure Test Port

1-

Fan Reverse Rotation Control Solenoid Valve

23-

Fan Reverse Rotation Spool Anti-Void Valve

4-

Fan Speed Control Solenoid Valve

T3-3-3

5-

Air Bleeder Plug

SECTION 3 COMPONENT OPERATION Group 3 Cooling Fan System Normal Rotation 1. Pressurized oil from unloader valve (8) is supplied to fan reverse rotation spool (4) in fan control valve (1).

2. As fan reverse rotation control solenoid valve (5) is not energized, fan reverse rotation spool (4) is pushed by the spring force. (Spool (4) is in the neutral position.)

3. Pressurized oil flows to the port A side of fan motor (2) from the B1 port of fan control valve (1) as shown.

4. Therefore, the fan rotates in normal direction.

T3-3-4

SECTION 3 COMPONENT OPERATION Group 3 Cooling Fan System Fan Control Valve (Normal Rotation)

95TNED-02-04-035

95TNED-03-03-05

b-

Fan Speed Control Solenoid Valve Control Signal (From MC Sub)

P- From Pump T- To Tank A1- To Fan Motor B Port

B1- To Fan Motor A Port LS- To LS Port

1234-

Fan Control Valve Fan Motor Anti-Void Valve Fan Reverse Rotation Spool

5-

78910-

6-

Fan Reverse Rotation Control Solenoid Valve Fan Speed Control Solenoid Valve

T3-3-5

Orifice Unloader Valve Hydraulic Tank Accessory Pump

11- Return Spring

SECTION 3 COMPONENT OPERATION Group 3 Cooling Fan System Reverse Rotation 1. When the fan reverse rotation switch is turned ON, fan reverse rotation control solenoid valve (5) is shifted by the signal (a) from the Main Controller (MC) (Sub). (Refer to SYSTEM / Control System.)

2. Pressurized oil from unloader valve (8) is routed to the end of fan reverse rotation spool (4) to shift spool (4). (Spool (4) is fully stroked.)

3. Pressurized oil flows to the port B side of fan motor (2) from the A1 port of fan control valve (1) as shown.

4. Therefore, the fan rotates in reverse direction.

T3-3-6

SECTION 3 COMPONENT OPERATION Group 3 Cooling Fan System Fan Control Valve (Reverse Rotation)

95TNED-02-04-052

95TNED-03-03-06

b-

Fan Speed Control Solenoid Valve Control Signal (From MC Sub)

P- From Pump T- To Tank A1- To Fan Motor B Port

B1- To Fan Motor A Port LS- To LS Port

1234-

Fan Control Valve Fan Motor Anti-Void Valve Fan Reverse Rotation Spool

5-

78910-

6-

Fan Reverse Rotation Control Solenoid Valve Fan Speed Control Solenoid Valve

T3-3-7

Orifice Unloader Valve Hydraulic Tank Accessory Pump

11- Return Spring

SECTION 3 COMPONENT OPERATION Group 3 Cooling Fan System Switching from Normal to Reverse Rotation Fan reverse rotation control solenoid valve (5) acts to send pressurized oil into the pilot chamber and moves fan reverse rotation spool (4),

95Z7-03-03-02

Pilot Chamber

95Z7-03-03-03

123-

Fan Control Valve Fan Motor Anti-Void Valve

45-

Fan Reverse Rotation Spool Fan Reverse Rotation Control Solenoid Valve

67-

T3-3-8

Fan Speed Control Solenoid Valve Orifice

11- Return Spring

SECTION 3 COMPONENT OPERATION Group 3 Cooling Fan System Fan Speed Control 1. The Main Controller (MC) (Sub) activates fan speed control solenoid valve (6) according to coolant temperature, torque converter oil temperature, hydraulic oil temperature, etc. (Refer to SYSTEM / Control System.)

2. Fan speed control solenoid valve (6) controls the pressure in chamber A (LS control pressure) so that the difference between this LS control pressure and the pump delivery pressure becomes constant.

95TNED-03-03-07

PT-

From Pilot Pump To Hydraulic Tank

LS- To LS Port A- LS Control Pressure Chamber

67-

Fan Speed Control Solenoid Valve Orifice

T3-3-9

SECTION 3 COMPONENT OPERATION Group 3 Cooling Fan System Make-Up Function The make-up valve keeps the hydraulic fan drive from developing what are known as cavitation ("voids" or vacuum pockets) when slowing down or while reversing the fan rotation. Sudden decreases in rpm’s (min-1) can cause voids (cavitation) to occur, and these voids would produce a symptom of delays in response to directional changes or delays in changes in fan speed.

If a make-up valve sticks closed, these delays can occur. If it were to stick in the open position, the speed in a given direction would be affected, making the fan rotate much more slowly than normal when that direction is selected.

The following explains the make up function.

1. When pressure at port A1 or port B1 is lower than pressure at port T (hydraulic tank), anti-void valve (3) moves.

2. Hydraulic oil in port T flows to port A1 or port B1 and cavitation is prevented.

3. When pressure at the port A1 or port B1 side rises to the specified pressure, check valve (3) is closed by the spring (12) force.

95TNED-03-03-08

T-

To Hydraulic Tank

A1- To Fan Motor (Reverse Rotation Side)

3-

Anti-Void Valve (Poppet)

12- Spring

B1- To Fan Motor (Normal Rotation Side)

T3-3-10

SECTION 3 COMPONENT OPERATION Group 4 Steering Pilot Valve Steering Pilot Line Pressurized oil from accessory pump (2) or main pump is sent to reducing valve (4), where the oil is regulated to the specific pressure, and supplied to steering pilot valve (1).

Steering pilot valve (1) supplies the regulated pressurized oil to steering valve (3) through joystick steering control valve (7) in proportion to the operating angle of joystick steering lever (8), thereby carrying out remote control of the spool of the main steering valve.

(Refer to SYSTEM / Hydraulic System / Steering Operation Control Circuit.)

T3-4-1

SECTION 3 COMPONENT OPERATION Group 4 Steering Pilot Valve Unit Location

115Z7-03-04-01

12-

Steering Pilot Valve Accessory Pump

34-

Steering Valve Reducing Valve

56-

T3-4-2

Stop Valve Drain Block

78-

Joystick Steering Control Valve Joystick Steering Lever

SECTION 3 COMPONENT OPERATION Group 4 Steering Pilot Valve

115T4GB03-04-09

123-

Steering Pilot Valve Accessory Pump Steering Valve

456-

Reducing Valve Stop Valve Drain Block

789-

T3-4-3

Joystick Steering Control Valve Joystick Steering Lever Steering Cylinder

10- Steering Accumulator 11- Main Pump

SECTION 3 COMPONENT OPERATION Group 4 Steering Pilot Valve Steering Pilot Valve Operation

Pressure at the output port also works on the bottom of spool (7), pushing up spool (7).

When the joystick steering lever is located in the neutral position, it is held by springs (3)(4). Spool (7) closes the pump port and opens the tank port.

When the joystick steering lever is shifted from the neutral position, cam (12) moves to push down spool (7) via push rod (13), spring seat (2) and return spring (3).

When the joystick steering lever is further shifted, the hole of spool (7) is connected with the notch (A).

Pressurized oil from port P flows to the output port 1 or 2 through the notch (A). The pressure at the output port is increased.

This supplies pilot oil to the joystick steering control valve, accordingly supplies pilot pressure to steering valve to move the plunger of the steering valve.

While the pressure to push up spool (7) is smaller than the spring force of balance spring (4), balance spring (4) is not compressed. Therefore, port P and the output port remain connected, and the pressure at the output port keeps increasing.

When the pressure at the output port increases to be larger than the force of balance spring (4), spool (7) moves upwards, compressing balance spring (4).

When spool (7) moves upward, the notch part closes, and pressure oil stops flowing from port P to the output port.

And pressure increase at the output port is stopped.

By the operating angle of the joystick steering lever, that is, the stroke of push rod (13), spool (7) is balanced in proportion to the spring force of balance spring (4) and the oil pressure reaction of the corresponding port. Then, the oil pressure of the corresponding port is determined.

When the oil pack pressure of the steering valve decreases, spool (7) is pushed down again to close the tank port and open the pump port so that the oil pack pressure rises.

As described above, the oil pack pressure of the steering valve is always kept at a constant pressure in accordance with the lever operating angle.

T3-4-4

SECTION 3 COMPONENT OPERATION Group 4 Steering Pilot Valve Structure Steering lever movable range 1

8

12.4

12.4

9 10 11 12

13

2 3 4 5

T Hole Notch A

6

P

7 Port 1

Port 2 115Z7-03-04-02

Port 1Port 21234-

For Steering (Right) For Steering (Left)

Boot Spring Seat Return Spring Balance Spring

P-

Port P (from Accessory Pump or Main Pump)

T-

Port T (to Hydraulic Tank)

5678-

Shim Washer Spool Set Screw

9101112-

Camshaft Bush Ball Cam

T3-4-5

13- Push Rod

SECTION 3 COMPONENT OPERATION Group 4 Steering Pilot Valve Joystick Steering Control Valve The joystick steering control valve has two spools.

Main spool (1) is movable and controls the pilot oil flow and selects the appropriate oil passage to A2 or B2 port for the designated steering direction.

The other one (2) is a fixed spool, and forms the oil passages to A2 and B2.

When main spool (1) is in the neutral position, both pilot ports (Pia, Pib) are connected to the hydraulic tank. Main spool (1) is balanced by return spring (3). All oil passages to A2 and B2 ports are closed.

Arrow View Y 115Z7-03-04-06

T3-4-6

SECTION 3 COMPONENT OPERATION Group 4 Steering Pilot Valve

Pia 1

3

T

Circuit Diagram

B2 P

A2 1 2

3

LS

Pib

Cross Section Z

12-

Main Spool Spool

3-

115Z7-03-04-03

Return Spring

T3-4-7

SECTION 3 COMPONENT OPERATION Group 4 Steering Pilot Valve Joystick Steering Control Valve Operation Right Turn When the joystick steering lever is shifted to the right, pressurized oil is sent to Pib port via the steering pilot valve.

The main spool moves to connect A2 port with pump port (P) and B2 port with tank port (T). The oil amount is controlled by the spool openings.

Pia

B2

T

P A2

Main spool

Pib

T3-4-8

115Z7-03-04-04

SECTION 3 COMPONENT OPERATION Group 4 Steering Pilot Valve Left Turn When the joystick steering lever is shifted to the left, pressurized oil is sent to Pia port via the steering pilot valve.

The main spool moves to connect B2 port with pump port (P) and A2 port with tank port (T). The oil amount is controlled by the spool openings.

Pia

B2

P A2

T

Main spool

Pib

T3-4-9

115Z7-03-04-05

SECTION 3 COMPONENT OPERATION Group 4 Steering Pilot Valve (Blank)

T3-4-10

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Outline The steering valve is located between the main pump and the steering cylinders.

The steering valve supplies pressurized oil from the main pump to the steering cylinders in response to pilot pressure of the steering pilot valve.

Steering cylinders are protected with the overload relief valve.

Steering Valve Overview

90TNED-03-05-01

T3-5-1

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Steering Valve Main Component 1. Steering spool

4. Load check valve

The movement of the steering spool is controlled by the oil pressure supplied from the joystick steering control valve to the main steering valve oil pack. At the center of the spool, there is a variable orifice with chamfers (throttle grooves). This orifice controls the oil flow rate.

Applies a positive back pressure to oil returning from the cylinders.

8. Main relief valve The main relief valve controls the maximum operating pressure when shifting the joystick steering lever.

2,3. Overload relief valves with make-up function

9. Meter-In compensation spool

These valves prevent excessive high pressure caused by external force and a vacuum (negative pressure) in the steering oil line.

This is the flow control spool sending oil to the steering line depending on the displacement of the steering spool. The excess oil goes to the loading line.

115TNED-03-05-05

AB-

Port A: Pressure for Steering (Left) Port B: Pressure for Steering (Right)

PT-

Port P: From Main Pump Port T: Return to Hydraulic Tank

Pa- Port Pa: Pilot Pressure for Steering (Left) Pb- Port Pb: Pilot Pressure for Steering (Right)

123-

Steering Spool Overload Relief Valve Overload Relief Valve

456-

Load Check Valve Variable Orifice Fixed Orifice

89-

T3-5-2

Main Relief Valve Meter-In Compensation Spool

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Steering Valve Cross Section View

90TNED-03-05-03

Section A-A 90TNED-03-05-04

Section B-B 90T4GB-03-04-06 123-

Steering Spool Overload Relief Valve Overload Relief Valve

456-

Load Check Valve Variable Orifice Fixed Orifice (with Filter)

8- Main Relief Valve 9- Meter-In Compensation Spool 10- Poppet

T3-5-3

11- Spring

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Operation Neutral Position When steering spool (1) is in the neutral position, variable orifice (5) in steering spool (1) closes to stop flow of the pressurized oil from the steering pump, and the oil will not be supplied to the steering cylinders.

T3-5-4

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve

90Z7-03-05-01

1-

Steering Spool

5-

Variable Orifice

T3-5-5

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Steering (Left Turn Position) When the joystick steering lever is tilted to the left, pilot pressure oil from the joystick steering control valve flows to port Pa and spool (1) moves left.

Pressurized oil from the main (steering) pump flows to the steering cylinders through port P and variable orifice (5) and load check valve.

The pressurized oil moves the cylinder rods and the machine turns to the left.

During low-speed turning: 1. Displacement of steering spool (1) is small. However, since the oil flow rate to the steering cylinder is reduced at variable orifice (5) at the spool center, the pressure difference between the front and rear of the orifice is increased.

2. When the pressure difference is increased to a specified value, meter-in compensation spool (2) is opened to discharge excess oil to the loading line.

3. In this way, extreme increase in the amount of the oil from the main pump to the cylinder is prevented.

During high-speed turning: 1. Steering spool (1) is pushed all the way to the left, and variable orifice (5) is fully opened. Under such a condition, all the oil is used for steering to enable high-speed turning.

2. At a low engine speed, the oil flow rate from the main pump is low, therefore the pressure difference between the front and rear of variable orifice (5) is small, and meter-in compensation spool (2) opens the passage to steering spool (1).

3. At a high engine speed, oil flow rate to variable orifice (5) is increased, therefore the pressure difference between the front and rear of variable orifice (5) is increased. Meter-in compensation spool (2) moves to close the passage to steering spool (1).

4. Thus, oil flow to the steering cylinder is controlled, and the excess oil is sent to the loading line.

T3-5-6

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve

90Z7-03-05-02

1-

Steering Spool

5-

Variable Orifice

9-

T3-5-7

Meter-In Compensation Spool

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Steering Valve Meter-In Compensator When the pump discharge amount is small, the pressure difference between the chambers A and B is small (pressure PA in chamber A nearly equals to pressure PB in chamber B), and meter-in compensation spool (2) is being pushed to the left by spring (3).

Accordingly, the oil sent from the pump flows to the steering circuit.

When the pump discharge amount is increased and the pressure difference (PA-PB) is increased to a specified value or more, meter-in compensation spool (2) starts to be shifted to the right and the excessive oil is bypassed to the loading circuit.

As described above, the steering circuit is given priority in receiving the pressurized oil from the pump.

However, when the number of rotations of the engine becomes larger and the oil flow rate exceeds the preset value, the meter-in compensation spool (2) bypasses the excessive oil to the loading circuit. This keeps the oil flow rate constant in the steering circuit.

T3-5-8

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Meter-in Compensation Spool Operation When the pump discharge amount is small:

90Z7-03-05-04

When the pump discharge amount is increased:

90Z7-03-05-05

a-

From Pump

b-

To Steering Circuit

1-

Steering Spool

2-

Meter-In Compensation Spool

3-

T3-5-9

Spring

4-

Variable Orifice

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Steering Main Relief Valve Normal Operation: When the pressure is at the preset value or less, steering spool (1) is open. The chambers A and B are filled with oil, and meter-in compensation spool (2) is balanced in the position shown in the figure to the right.

Relief Operation: When the pressure in the cylinder circuit exceeds the preset value (and the oil pressure rises naturally in both the chambers A and B), main relief valve (3) opens and the oil in the chamber B escapes into the tank circuit.

As a result, the pressure in the chamber A becomes relatively high, meter-in compensation spool (2) is shifted to the right, and the oil sent from the pump flows into the loading circuit.

T3-5-10

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Main Relief Valve Operation Normal Operation:

90Z7-03-05-06

Relief Operation:

90Z7-03-05-07

a-

From Pump

b-

To Tank

c-

To Steering Cylinder

1-

Steering Spool

2-

Meter-In Compensation Spool

3-

Main Relief Valve

T3-5-11

d-

From Steering Cylinder

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Steering Overload Relief Valve Overload relief valves with makeup valve are located in the circuit between the steering cylinder and the steering spool on the both sides of the steering cylinder.

While the steering spool is located in the neutral position, the steering cylinder circuits are closed.

Overload Relief Function In this situation, if an external shock (force) is applied to one side of the cylinder (the bottom side in the figure to the right) causing abnormally high pressure to build up in the circuit, the oil escapes through the valve on side A, in order to prevent damage to the piping and the cylinder.

Makeup Function On the other side of the cylinder (the rod side in the figure to the right), the oil is allowed to enter from the drain to tank circuit as is required from the oil that escaped from the bottom side of the cylinder, in order to prevent vacuum (negative pressure (or void)) from developing in the circuit.

T3-5-12

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve

90Z7-03-05-08

a-

External Force

b-

To Tank

1-

Overload Relief Valve (Overload Relief Function)

2-

Overload Relief Valve (MakeUp Function)

T3-5-13

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Overload Relief Valve Operation When the oil pressure is at the preset valve or less, the pressurized oil from the cylinder is sent to the chamber B through the hole A of piston (1), but poppet (2) does not move.

Plunger (4) is pressed against sleeve (3) by the spring force.

Also sleeve (3) completely closes the cylinder port by the pressure area difference of the sleeve between the cylinder port side and the chamber B side.

When the oil pressure in the cylinder line rises above the pressure set by the spring, poppet (2) is moved to the right and opens the port.

Then the oil in the chamber B flows to the tank through clearance between the body and sleeve (3).

As a result, the pressure in the chamber B rapidly lowers and plunger (4) is moved right.

Then plunger (4) opens the port to the tank port and the pressurized oil in the cylinder port escapes to the tank port.

T3-5-14

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Overload Relief Valve Operation When the oil pressure is at the preset value or less:

90T107-02-05-19

When the oil pressure exceeds the preset value:

90T178-03-03-49

A-

Orifice

a-

From Cylinder

b-

To Tank

1-

Piston

2-

Poppet

3-

Sleeve

T3-5-15

4-

Plunger

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Make-Up Valve Operation When the pressure is reduced below the tank pressure, the make-up valve is opened.

When the pressure at the cylinder port becomes less than tank pressure, sleeve (3) is moved to the right by the pressure area difference of the sleeve between the right and left (Y-X). Sleeve (3) opens the port and the oil flows to the cylinder port. It prevents a vacuum (negative pressure) in the cylinder.

90T178-03-03-50

a-

To Cylinder

3-

Sleeve

b-

From Tank

T3-5-16

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Steering Spool Variable Orifice When the steering spool is pushed in, variable orifice (5) is opened, and the pressurized oil from the pump goes through variable orifice (5).

The pressure generated before and after variable orifice (5) leads to the chambers A and B.

The pressure difference varies depending on the opening area of variable orifice (5) and the passing oil flow rate, and the control pressure is set to 0.6 MPa (6.1 kgf/cm2) (87 psi).

90Z7-03-05-03

T3-5-17

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Steering Pilot Circuit and Its Operation 1. The pilot oil from steering pilot valve (1) flows to joystick steering control valve (7) and moves the main spool. The oil amount in proportion to the spool stroke is supplied to the steering valve.

2. This pilot oil from joystick steering control valve (7) first enters end cover (2) of the steering valve, then passes through steering spool flow amplifier notch (4) and pilot orifice (5), and flows to end cover (2) on the opposite side, returning to the tank through joystick steering control valve (7).

3. As the amount of oil flowing through amplifier notch (4) and pilot orifice (5) increases, the pressure of the oil inside end cover (2) increases, pushing in steering spool (3).

4. The variable orifice opens, regulating the amount of oil flowing to the cylinder circuit, depending on flow volume, and thus the distance the spool is pushed in.

T3-5-18

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Steering Pilot Circuit

115Z7-03-05-09

Port A:

123-

To Steering Cylinder

Steering Pilot Valve End Cover Steering Spool

Port B:

45-

From Steering Cylinder

Flow Amplifier Notch Pilot Orifice

Port P:

67-

T3-5-19

From Pump

Meter-In Compensation Spool (Steering Valve) Joystick Steering Control Valve

Port T:

To Tank

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve Flow Amplifier Notch and Pilot Orifice 1. If no oil is sent from the joystick steering control valve, the spool is held in the neutral position by return spring (6) and flow amplifier notch (4) is closed.

2. When pilot oil is sent from the joystick steering control valve, the oil flows through pilot orifice (5), the pressure of the oil inside end cover (2) rises, pushing the spool and opening flow amplifier notch (4).

90Z7-03-05-10

3. Then, the oil flows through flow amplifier notch (4) and pilot orifice (5).

P-

Pilot Oil

24-

End Cover Flow Amplifier Notch

T3-5-20

56-

Pilot Orifice Return Spring

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve When pilot flow is low: When the spool is pushed in a little, opening the flow amplifier notch (1) a little, the pilot oil easily flows out, and the spool will not be pushed in any further.

(The hydraulic force applied at the end of the spool (H) is in balance with the force of the return spring (S).)

90Z7-03-05-11

When pilot flow rises: As the opening of the flow amplifier notch (1) is narrow, the pressure inside the end cover is raised higher, pushing the spool in.

When the spool is pushed in, the opening of the flow amplifier notch (1) becomes larger, making it easier for pilot oil to flow out; thus, the rise in pressure stops and the spool is stopped at a position where the hydraulic force applied to the end of the spool (H) is in balance with the force of the return spring (S).

90Z7-03-05-12

PH-

Pilot Pressure Hydraulic Force

S-

Return Spring Force

1-

Flow Amplifier Notch Opening

2-

Pilot Orifice

T3-5-21

SECTION 3 COMPONENT OPERATION Group 5 Steering Valve (Blank)

T3-5-22

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve Outline (Fingertip Control Type Pilot Valve for Front Attachment) The pilot valve controls pilot pressure oil in order to move the spool in the control valve.

The pilot valve delivers pilot pressure oil in proportion to the control lever stroke. This is done by using a Pressure Proportional Control (PPC) Valve which moves the spool in the control valve.

Port No. 1 2 3 4

Bucket Dump Bucket Roll Back Lift Arm Lower Lift Arm Raise

Hydraulic Symbol

P T 2

1

4

3 T4GB-03-05-001

90T4GB-03-05-02

PT-

T3-6-1

Port P (Pressure Oil from Pilot Pump) Port T (To Hydraulic Oil Tank)

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve Operation Neutral (Output Curve: A to B) 1. At the neutral position of the control lever, spool (7) is completely blocking the pressurized oil from port P. Also, output port (Y) is connected to tank port (T) through notch part (Z) of spool (7), and the pressurized oil in output port (Y) is equal to the pressure in the hydraulic tank.

F

D

2. When the control lever is moved slightly, lever (1) is tilted, and push rod (2) and push rod (3) are pushed in. Push rod (3) and spring guide (4) remain mutually connected, and move downward, compressing return spring (6).

3. At this time, spool (7) is pushed by balance spring (5), and moves downward until the clearance (X) becomes zero.

E

a

C

A

b

B

T523-02-05-001 a-

4. During this movement, output port (Y) remains connected with tank port (T), and pressurized oil is not supplied to output port (Y).

fNOTE: Lever stroke during the period when the

clearance (X) becomes zero is the play of the control lever.

T3-6-2

Pilot Pressure

b-

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve

1 2

3

4 5 6 T X

X Z

P

7 Y

T4GB-03-05-004

T4GB-03-05-003

P-

Pilot Pressure Port

T-

Tank Port

X-

Clearance

Z-

Notch Part

12-

Lever Push Rod

34-

Push Rod Spring Guide

Y-

Output Port

56-

Balance Spring Return Spring

T3-6-3

7-

Spool

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve While Metering Pilot Oil (Output Curve: C to D)

Full Stroke (Output Curve: E to F)

1. When the control lever is further tilted, output port (Y) is connected with pilot pressure port (P) through spool (7).

1. When the control lever is fully stroked, push rod (3) moves downward until spring guide (4) contacts the shoulder part of the casing.

2. Pressurized oil from Port P flows into output port (Y) through spool (7), and the pressure in output port (Y) is raised.

2. At this time, spool (7) is directly pushed by the bottom of push rod (3). Therefore, output port (Y) remains connected to the port P through notch part (Z) of spool (7) because even if the pressure at the output port is raised, spool (7) does not move upward.

3. Pressure in output port (Y) works spool (7), and tends to push up spool (7).

4. In case the force to push up spool (7) is less than the balance spring (5) force, balance spring (5) does not compress. The port P and output port (Y) remain connected, and the pressure in output port (Y) keeps rising.

3. As a result, the pressure at the output port end is equal to the pressure at port P. Stroke amount C of the stem determines the total stroke of the lever.

5. When the pressure in output port (Y) rises the force to push spool (7) up increases. If this force overcomes the balance spring (5) force, spool (7) moves upwards, compressing balance spring (5).

E

a

F

D

6. When spool (7) moves upward, output port (Y) is not connected any longer, and pressurized oil stops flowing from port P to output port (Y). And pressure in output port (Y) stops increasing.

C

7. In this way, balance spring (5) is compressed in proportion to the amount spool (7) is pushed down, and the pressure in output port (Y) is the balanced pressure working on the spring force and spool (7).

A

b

B

T523-02-05-001 a-

T3-6-4

Pilot Pressure

b-

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve

3

5

C

T

4 Z P

P

7

Y

P-

Pilot Pressure Port

Z-

Notch Part

3-

Push Rod

7

Y

T4GB-03-05-005

T-

Tank Port

Y-

Output Port

4-

Spring Guide

5-

Balance Spring

T3-6-5

7-

Spool

T4GB-03-05-006

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve Electromagnetic Detent 1. Coil for detent is installed at the push rod part of the pilot valve.

2. When one of the control levers is tilted, push rod (2) and plate (8) of the opposite side are pushed upwards by the spring force.

3. If the control lever is fully stroked, plate (8) of the opposite side (forced up side) is held by electromagnetic coil assembly (10). This holds the control lever at it’s position.

4. This electromagnetic attraction between coil assembly (10) and plate (8) continues until coil assembly (10) is deenergized or until the magnetic force is forcibly separated by operating the control lever toward the neutral direction with enough force to overcome the power of detent.

2

10

8

90T4GB-03-05-07

2-

Push Rod

8-

Plate

10 - Coil Assembly

T3-6-6

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve Outline (Joystick Type Pilot Valve for Front Attachment) The pilot valve controls pilot pressure oil in order to move the spool in the control valve.

The pilot valve delivers pilot pressure oil in proportion to the control lever stroke. This is done by using a Pressure Proportional Control (PPC) Valve which moves the spool in the control valve.

Port No. 1 2 3 4

Lift Arm Lower Bucket Dump Lift Arm Raise Bucket Roll Back

Hydraulic Symbol

P T 2

1

3

4 T4GB-03-05-001

P

3

4

2

T

PT-

T3-6-7

Port P (Pressure Oil from Pilot Pump) Port T (To Hydraulic Oil Tank)

1

TNED-03-06-002

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve (Blank)

T3-6-8

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve Operation The spool (7) head comes in contact with the upper surface of spring guide (4). Spring guide (4) is kept raised by return spring (6).

1

fNOTE: Total lever stroke is determined by stroke dimension (X) of stem (2).

X

2 4 7

5

6 8 3 TNED-03-06-003

12-

Cam Stem

34-

Case Spring Guide

56-

T3-6-9

Balance Spring Return Spring

78-

Spool Hole

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve Neutral (Output Curve: A to B) 1. When in neutral, spool (7) completely blocks pressurized oil from port P (pilot pump). In addition, output port (Y) is opened to the tank port (T) (hydraulic tank) through the inner passage in the lower part of spool (7).

E

a

F

D

2. Therefore, pressure in output port (Y) is equal to the pressure of the tank port (T).

3. When the control lever is slightly tilted, cam (1) is tilted and stem (2) is pushed downward. Stem (2) compresses return spring (6) along with spring guide (4) together.

C

A

4. At this time, as pressure in output port (Y) is equal to that in the tank port T, spool (7) moves downward due to the balance spring (5) force that is caged between spring guide (4) and spool (7). Note that the lower surface of the upper head of spool (7) remains in contact with spring guide (4).

b

B

T523-02-05-001 a-

5. This downward movement of spool (7) and port alignment continue until hole (8) on spool (7) is connected to port P.

T3-6-10

Pilot Pressure

b-

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve

7

1

1

2

2

4

4 7

5

T

T

6

P

Y

5

6

8

8

3

3 P

TNED-03-06-003

P-

Pilot Pressure Port

T-

Tank Port

Y-

Output Port

12-

Cam Stem

34-

Case Spring Guide

56-

Balance Spring Return Spring

T3-6-11

Y

78-

TNED-03-06-004

Spool Hole

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve While Metering Pilot Oil (Output Curve: C to D) 1. When the control lever is further tilted and stem (2) is moved further downward, hole (8) on spool (7) is connected to port P and pressurized oil in port P flows to output port (Y).

E

a

D

2. Pressure in output port (Y) is routed to the bottom surface of spool (7) so that spool (7) is pushed upward. This upward force is seen by the operator as lever feedback pressure, and contributes to operational feel and hydraulic pilot modulation.

C

3. When the force to move spool (7) upward is less than the balance spring (5) force, balance spring (5) does not compress. The result is that spool (7) does not raise and pressure in output port (Y) increases.

4. As pressure in output port (Y) increases the force to move spool (7) upward increases. When this force overcomes the balance spring (5) force, spool (7) compresses balance spring (5) and moves upward.

F

A

b

B

T523-02-05-001 a-

5. As spool (7) moves upward, hole (8) is closed so that pressurized oil from port P stops flowing to output port (Y) and pressure in output port (Y) stops increasing.

6. As spool (7) moves downward and balance spring (5) is compressed, pressure routed to the bottom surface of spool (7) increases until pressure balances with the increasing spring force. This increasing pressure is equal to the pressure in output port (Y).

T3-6-12

Pilot Pressure

b-

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve

7

1

1

2

2

4

4 7

5

T

T

6

P

Y

5

6

8

8

3

3 P

TNED-03-06-005

P-

Pilot Pressure Port

T-

Tank Port

Y-

Output Port

12-

Cam Stem

34-

Case Spring Guide

56-

Balance Spring Return Spring

T3-6-13

Y

78-

TNED-03-06-006

Spool Hole

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve Full Stroke (Output Curve: E to F) 1. When the control lever is fully stroked, the balance spring (5) force (force to push spool (7) downward) is greater than pressure in output port (Y) (force to push spool (7) upward).

E

a

F

D

2. Therefore, even if pressure in output port (Y) increases further, hole (8) on spool (7) remains open.

3. Consequently, pressure in output port (Y) is equal to that in port P.

C

A

b

B

T523-02-05-001 a-

T3-6-14

Pilot Pressure

b-

Control Lever Stroke

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve

1

2 4 7

5 T

6 8 3 P

Y

TNED-03-06-007

P-

Pilot Pressure Port

T-

Tank Port

Y-

Output Port

12-

Cam Stem

34-

Case Spring Guide

56-

Balance Spring Return Spring

T3-6-15

78-

Spool Hole

SECTION 3 COMPONENT OPERATION Group 6 Pilot Valve Electromagnetic Detent 1. The coil for detent is installed inside the pilot valve.

2. If the control lever is fully stroked, plate (9) is held by electromagnetic coil assembly (10).

3. This electromagnetic attraction between coil assembly (10) and plate (9) continues until coil assembly (10) is deenergized or until the magnetic force is forcibly separated by the operator by means of physically overpowering the magnetic force on the control lever.

9

10

TNED-03-06-007

9-

Plate

10- Coil Assembly

T3-6-16

SECTION 3 COMPONENT OPERATION Group 7 Charging Circuit Outline The charging circuit block consists of unloader valve (brake charge valve) (4), and combination valves (1, 2).

Unloader valve (4) supplies pressurized oil from the accessory pump, with priority to service brake accumulators (5), brake valve (6), and the fan motor circuit. Unloader valve (4) also supplies pressurized oil to combination valves.

The combination valve consists of manifold block (1), solenoid valve block (2), and reducing valves (3).

Manifold block (1) supplies pressurized oil from unloader valve (4) to the torque control solenoid and parking brake.

Manifold block (1) also supplies pressurized oil to solenoid valve block (2), which has auto brake solenoid valve and loading circuit control solenoid valve.

When the front control lever lock solenoid valve is shifted, manifold block (1) also supplies pressurized oil to the pilot valve.

Pressurized oil to the optional ride control circuit is also supplied via manifold block (1).

115TNED-03-07-14

1234-

Combination Valve (Manifold Block) Combination Valve (Solenoid Valve Block) Reducing Valves Unloader (Brake Charge) Valve

567-

Service Brake Accumulators Brake Valve Pressure Sensor (Service Brake Primary Pressure)

T3-7-1

89-

Pressure Sensor (Loading Primary Pilot Pressure) Pressure Sensor (Parking Brake)

SECTION 3 COMPONENT OPERATION Group 7 Charging Circuit Brake Charge Valve (Unloader Valve) The unloader valve controls the flow rate and the pressure of the pressurized oil from the accessory pump to the service brake accumulators.

Spool (2) opens and closes the port to the fan motor.

Orifice (7) regulates the flow rate to the accumulator port with high priority.

The pressure governor mechanism controls the pressure on the accumulator port side.

Operation 1. While the unloader valve is not operating, spool (2) is pushed back by spring (1) and the pump port to the fan motor port is closed. Oil flowing from pump port (P) is sent to accumulator port (AC) through orifice (7), and the pressure at the accumulator port increases accordingly.

95TNED-03-07-15

2. When an excess flow rate is generated, spool (2) moves to the fan motor port side and the excess flow rate flows out to the port to the fan motor.

3. The pressure at accumulator port (AC) is transferred to the inside of the pressure governor through orifice (8).

4. When the pressure at accumulator port (AC) increases and exceeds the load of springs (5, 6) applied on pilot valve (4), pilot valve (4) opens to send the oil to tank port (T) and increase of the pressure at accumulator port (AC) stops (cut-out pressure).

To fan circuit

P- From Pump T- To Hydraulic Tank AC- To Accumulators (Via Reducing Valve Block)

PP- Pilot Port (Accumulator Feedback Port) LS- Load-Sensing Port

237-

8- Orifice 12- Filter

5. At this time, the pressure in the accumulator connected to the pilot port pushes governor plunger (3), and continuously releases pilot valve (4).

5. When the pressure in the accumulator decreases and the spring attached to pilot valve (4) pushes back governor plunger (3), pilot valve (4) is closed and the pressure at accumulator port (AC) starts to increase again (cut-in pressure).

T3-7-2

Spool Governor (Plunger) Orifice

SECTION 3 COMPONENT OPERATION Group 7 Charging Circuit

95TNED-03-07-17 PT-

From Pump To Hydraulic Tank

AC- To Accumulators (Via Reducing Valve Block)

PP- Pilot Port (Accumulator Feedback Port)

LS- Load-Sensing Port)

123-

Spring Spool Governor Plunger

456-

789-

10- Adjusting Screw 11- Lock Nut 12- Filter

Valve Pilot Spring Spring

T3-7-3

Orifice Orifice Test Port

SECTION 3 COMPONENT OPERATION Group 7 Charging Circuit Combination Valve (Manifold Block) The manifold valve of combination valve supplies pressurized oil from the unloader valve (brake charge valve), decontaminated by line filter (7) and regulated by reducing valve (8), to the main pump (torque control solenoid valve), loading circuit control solenoid valve unit, and auto brake solenoid valve.

(g) (a) (g)

Reducing valves (1)(8), parking brake solenoid valve (2), and loading pilot control lever lock solenoid valve (3) are equipped within the manifold valve.

(b) (d) (c)

Reducing valve (1) keeps the pilot pump pressure to the specified set pressure, while reducing valve (8) lowers the pressure to the specified level to protect the brake accumulators and the brake valve from high pressure.

(e)

Parking brake solenoid valve (2) is an ON/OFF solenoid valve. It is shifted by the signals from the parking brake switch and controls the oil supply to the parking brake.

(f) 115TNED-03-07-16

Loading pilot control lever lock solenoid valve (3) is also an ON/OFF solenoid valve. It is shifted by the front loading pilot control lever lock switch and supplies pilot pressurized oil to the pilot valve.

abcde-

From Unloader Valve To Unloader Valve To Pilot Valve To Parking Brake To Solenoid Valve Unit

f-

123-

Reducing Valve Parking Brake Solenoid Valve Loading Pilot Control Lever Lock Solenoid Valve Pressure Sensor (Loading Pilot Primary Pressure) Pressure Sensor (Parking Brake)

678910-

45-

T3-7-4

g-

To Main Pump (Torque Control Solenoid Valve), To Ride Control Accumulator (Opt) To Brake Valve

Parking Brake Line Filter Reducing Valve Check Valve Pressure Sensor (Service Brake Pressure Alarm)

SECTION 3 COMPONENT OPERATION Group 7 Charging Circuit

(c) (b)

(d)

(f)

(e)

(g)

(a) (f)

(c)

(b)

115TNED-03-07-07

abc-

From Unloader Valve To Unloader Valve To Pilot Valve

de-

123-

Reducing Valve Parking Brake Solenoid Valve Loading Pilot Control Lever Lock Solenoid Valve

4-

To Parking Brake To Solenoid Valve Unit

fg-

57-

Pressure Sensor (Loading Pilot Primary Pressure) Pressure Sensor (Parking Brake) Line Filter

T3-7-5

To Main Pump (Torque Control Solenoid Valve), To Ride Control Accumulator (Opt) To Brake Valve

8- Reducing Valve 9- Check Valve 10- Pressure Sensor (Service Brake Pressure Alarm)

SECTION 3 COMPONENT OPERATION Group 7 Charging Circuit Reducing Valve Reducing valve (1) keeps the pilot pump pressure to operate the parking brake and loader pilot valve functions.

Reducing valve (8) regulates the pressurized oil from the accessory pump via the unloader valve down to the specified level to protect the brake accumulators and the brake valve from the high-pressure oil, which may rise beyond the acceptable limit of these hydraulic parts.

The operation of reducing valve (1) is explained below.

1. Pressurized oil from the unloader valve via port A flows into the pilot oil circuit by way of passage Z. The oil pressure is applied also on chamber C byway of orifice 1 (2).

2. When the pressure in the pilot oil circuit is at or above the set pressure, the oil in chamber C unseats ball (3) by way of orifice 2 (4), and escapes to the tank by way of passage Y. 3. As a result, the pressure in chamber C decreases.

Then plunger (5) moves up and closes passage Z so that the pressure on the pilot oil circuit side does not exceed the set pressure.

4. When the oil pressure on the pilot oil circuit side becomes less than the set pressure, ball (3) is moved down and the pressure at chamber C becomes equivalent to the pressure on the pilot oil circuit side (B).

5. Therefore, plunger (5) moves down by a spring, opens the passage Z, then introduces the accumulator pressure to the pilot oil circuit side so that the pressure is maintained at the specified value.

115TNED-03-07-18

123-

T3-7-6

Reducing Valve Orifice1 Ball

45-

Orifice 2 Plunger

SECTION 3 COMPONENT OPERATION Group 7 Charging Circuit Combination Valve (Solenoid Valve Block) Parallel/tandem switching solenoid valve (1) is a proportional solenoid valves, shifted by the signals from MC (Sub) and controls the flow rate of the parallel circuit according to work load. (Refer to SYSTEM 2 / Parallel Circuit Flow Rate Control.)

Auto Brake solenoid valve (2) is also a proportional solenoid valves, shifted by the signals from MC (Main).

This applies service brake automatically. (Refer to SYSTEM 2 / Group 2 / Auto Brake Control, SYSTEM 2 / Group 4 / Auto Brake Circuit.)

Combination Valve (Manifold Block)

2

1

115Z7-01-02-07

115Z7-03-07-01

12-

T3-7-7

Parallel/Tandem Switching Solenoid Valve Auto Brake Solenoid Valve

SECTION 3 COMPONENT OPERATION Group 7 Charging Circuit Proportional Solenoid Valve The proportional solenoid valve is controlled by an electric current signal from MC (main controller) and provides output pressure in proportion to the electric current.

When in neutral 1. Spring (2) pushes spool (1) to the right and output port S is connected to tank port T.

When energized 1. Solenoid (3) pushes spool (1) to the left in proportion to the electrical current flowing through solenoid (3).

2. Pilot pressure oil from port P flows to output port S and pressure at output port S increases.

3. This pressure at output port S is routed to stepped part a of spool (1). Spool (1) is pushed to the right due to surface area differences at the spool surfaces indicated in illustration call out "a".

4. When pressure at output port S increases and the force to push spool (1) to the right overcomes the force to push spool (1) to the left by solenoid (3), spool (1) is moved back to the right and the passage between output port S and port P is closed. Therefore, pressure at output port S stops increasing, and oil flow is stopped.

T

1

P

S

2

3

a

a TDAA-03-07-013

1-

Spool

2-

Spring

3-

T3-7-8

Solenoid

SECTION 3 COMPONENT OPERATION Group 7 Charging Circuit Service Brake Accumulator The service brake accumulators are installed in the accumulator oil circuit of the unloader valve (brake charge valve).

High-pressure nitrogen gas is contained in the accumulator, and pressurized oil from the accessory pump compresses the nitrogen gas through the piston.

The brake circuit oil pressure is stored by compression of the nitrogen gas.

95ZV52058

1234-

Body Hydraulic Cap Gas Cap Piston

5678-

V-O-Ring Backup Ring Wear Ring O-Ring

9101112-

T3-7-9

Backup Ring Gas Valve Gas Valve O-ring Gas Valve Guard

13- Bolt

SECTION 3 COMPONENT OPERATION Group 7 Charging Circuit (Blank)

T3-7-10

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Outline The selectable range drive unit consists of transmission (2) and torque converter (1).

The selectable range drive unit is connected with the engine. The output power from the engine is transmitted to transmission (2) through the engine flywheel, torque converter (1) and first propeller shaft (3).

a

3

1 b

c

2

115T4GB-03-09-02

ab-

Engine Side 2nd Propeller Shaft (Front Axle) Side

c-

3rd Propeller Shaft (Rear Axle) Side

1-

Torque Converter

2-

Transmission

3-

T3-8-1

1st Propeller Shaft

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Transmission and Torque Converter Assy LU 5 4

1

19 2 20

6 7 View A

4 8

A 9 3

11 12

1 13

H 14

3 15

16 R

17 L

18 2

10

115Z7-03-08-01 123456-

Torque Converter First Propeller Shaft (Main) Transmission Air Breather Proportional Solenoid Valve (For Lock-Up Clutch) Torque Converter Oil Temperature Sensor

789-

Modulator Valve Mount Direct Charge Valve Transmission Oil Temperature Sensor 10- Speed Sensor (Switch Proximity) 11- T/M Control Valve (Clutch Solenoid Valve)

12- T/M Control Valve (Clutch Valve) 13- Proportional Solenoid Valve (For 1st Speed Clutch) 14- Proportional Solenoid Valve (For High Clutch) 15- Proportional Solenoid Valve (For 3rd Speed Clutch)

T3-8-2

16- Proportional Solenoid Valve (For Reverse Clutch) 17- Proportional Solenoid Valve (For Low Clutch) 18- Proportional Solenoid Valve (For 2nd Speed Clutch) 19- Accumulator (1, R) 20- Accumulator (2, 3, L, H)

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Drive Unit Hydraulic Circuit Diagram Neutral Position

Limit Switch

Clutch Valve Assembly

Modulator Valve Unit

Clutch Solenoid Valve Assembly

fNOTE: The orifice in the clutch valve 17, 19 and 23 is to reduce shock at clutch engagement.

115Z7-03-08-02

12345-

Transmission Oil Pan Strainer Torque Converter Gear Pump Line Filter with Bypass Valve Clutch Pressure Regulator Valve 6- Proportional Relief Valve 7- Priority Valve 8- T/C Inlet Relief Valve 9- Check Valve (1) 10- Check Valve (2) 11- Torque Converter 12- T/C Outlet Relief Valve

13- Oil Cooler 14- High Range Clutch Solenoid Valve 15- High Range Clutch Valve 16- Reverse Clutch Solenoid valve 17- Reverse Clutch Valve 18- Low Range Clutch Solenoid Valve 19- Low Range Clutch Valve 20- 1st Speed Clutch Solenoid Valve 21- 1st Speed Clutch Valve

22- 2nd Speed Clutch Solenoid Valve 23- 2nd Speed Clutch Valve 24- 3rd Speed Clutch Solenoid Valve 25- 3rd Speed Clutch Valve 26- High Range clutch 27- Reverse Clutch 28- Low Range Clutch 29- 1st Speed Clutch 30- 2nd Speed Clutch 31- 3rd Speed Clutch

T3-8-3

32- Accumulator (for Reverse, 1st Clutch Valve) 33- Accumulator (for High, Low, 2nd, 3rd Clutch Valve) 34- Direct Charge Valve 35- Lock-Up Clutch Solenoid Valve 36- Torque Converter (Lock-Up Clutch)

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Torque Converter (Lock-Up) The torque converter is equipped with the lock-up device.

The torque converter is located between the engine and transmission, and consists of three impellers as shown in the figure. The three impellers are pump (P), turbine (T), and stator (S) impellers.

When the lock-up clutch is engaged, the power from the engine is directly transmitted to the turbine. As a result, slip between the pump and the turbine is eliminated.

This is an advantage during high speed travel and in "load and carry" operations. Less fuel is used, higher ground speed can be reached, and less heat is generated.

The pump is connected to the engine flywheel, and rotates together with the engine.

The turbine is connected to the torque converter output shaft to transmit the power to the transmission.

The stator is fixed to the torque converter case.

The area of the impellers is filled with oil.

When the engine is started, the pump impeller rotates, therefore the oil will circulate to rotate the turbine impeller (circulation order: pump --> turbine --> stator --> pump). Oil is redirected by the fixed stator impeller back to the pump impeller. When the turbine impeller rotates, the power will be transmitted to the output shaft.

Lock-Up Clutch

Output

Input

95V2E32030

T3-8-4

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Cross Section View of Torque Converter

1

2

10 11 7

4

12 3 8 8

a b

5

9

6

115T4GB-03-09-01 a-

Input (Engine) Side

b-

Output (Propeller Shaft) Side

1234-

Turbine impeller Assy Pump Impeller Stator Lock-Up Piston

567-

Drive Cover P.T.O. Drive Gear Torque Converter Output Flange

891011-

T3-8-5

Turbine Shaft Stator Shaft Lock-Up Clutch Gear Friction Disc

12- Lock-Up Clutch Control Pressure Input Port

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Transmission Structure

1

7

4

6

2

3

5

115Z7-03-08-03

123-

Clutch Assembly Output Shaft Output Gear

456-

Output Flange (2nd Propeller Shaft Side) Output Flange (3rd Propeller Shaft Side) Output Flange (1st Propeller Shaft Side)

T3-8-6

7-

Transmission Input Gear

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Cross Section View of Transmission

115T4GB-03-09-04

12345-

Input Flange Low Range Clutch High Range Clutch Reverse Clutch 1st Speed Clutch

678910-

2nd Speed Clutch 3rd Speed Clutch Output Gear Output Shaft Output Flange (3rd Propeller Shaft Side)

T3-8-7

11121314-

Output Flange (2nd Propeller Shaft Side) Modulator Valve Unit Clutch Solenoid Valve Assembly Clutch Valve Assembly

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Clutch and Gear Train

1st Propeller Shaft

2nd Propeller Shaft

3rd Propeller Shaft

115V2E32008

RLH-

Reverse Clutch Low Range Clutch High Range Clutch

123-

First Speed Clutch Second Speed Clutch Third Speed Clutch

fNOTE: The number shows the number of gear teeth.

T3-8-8

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Operation of Transmission The transmission is powered hydraulically by hydraulic engagement of speed and directional ranges.

Clutch Combination The transmission is equipped with seven clutches.

Forward low range, forward high range, reverse, 1st, 2nd and 3rd speeds, and lock-up.

Combining the clutches as shown in the table here provides seven forward speeds, and three reverse speeds for a total of ten speeds.

Two or three clutches must be engaged at the same time to move the machine.

Speed Range F1 F2 F2L F3 F3L F4 F4L R1 R2 R3 N

L X X X X X

H

R

Engaged Clutch 1 X

2

3

X X

X X X

X X

X X X X X

X *

*: Either clutch is engaged.

T3-8-9

X X

X

*

LU

X *

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Shift Pattern and Shift Position Automatic or manual speed change is available depending on the selected shift position, as shown in the table.

Automatic speed change refers to one where the best speed range is determined by a controller according to the engine speed and the detected machine speed.

Drive Mode AUTO1

AUTO2

MANUAL

Shift Position 1st 2nd 3rd 4th 1st 2nd 3rd 4th 1st 2nd 3rd 4th

1 A B B B A

2

2L

Shift Range 3

3L

4

4L

A A A

C C C

B B

C C

B

B

A A A

C C C

B B

C C

B

B

A A A A

Shift pattern is applicable when A: Start position and shift down B: Shift up and shift down C: Shift up only (may not applicable depending on the condition)

NOTE:

x Lock-up function works during forward movement only. x Fourth speed range is available during forward movement only. x Fourth speed range is available over the specified speed in Manual Mode.

T3-8-10

B

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Clutch Pack Inlets of 2nd and 3rd Speed Clutch Oil

Inlets of Reverse and Low Range Clutch Oil

Inlet of 1st Speed Clutch Oil

Inlet of High Range Clutch Oil

Inlet of Lubricant and Cooler Oil

115Z7-03-08-04

123456789101112131415-

Clutch Input Shaft High Range Clutch Drum High Range Clutch Piston High Range Clutch Piston Return Spring Spider Friction Plate Steel Plate Reverse Clutch Piston Reverse Planetary Gear carrier Reverse Planetary Gear Reverse Ring Gear Reverse Sun Gear Friction Plate Steel Plate Anchor Pin

1617181920212223242526-

Piston Return Spring Low Range Clutch Piston Low Range Planetary Gear Low Range Ring Gear Low Range Sun Gear 3rd Speed Clutch Piston 3rd Speed Planetary Gear 3rd Speed Ring Gear 3rd Speed Sun Gear 2nd Speed Clutch Piston 2nd Speed Planetary Gear carrier / 1st Speed Clutch Gear 27- 2nd Speed Planetary Gear 28- 2nd Speed Ring Gear 29- 2nd Speed Sun Gear

T3-8-11

303132333435-

1st Speed Clutch Drum 1st Speed Clutch Piston Drop Gear 1st Speed Clutch Piston Return Spring Clutch Output Shaft Low/3rd Speed Planetary Gear Carrier

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Power Flow Path in the Transmission Forward First Speed Power Flow Path When first speed forward is selected by the operator or the computer, oil is sent from the modulator valve to the low range clutch and the 1st speed clutch.

19

When the clutch plates are pressed by the low range clutch piston, low range ring gear (19) is locked to the housing by the anchor pins (15). The torque converter rotates low range sun gear (20) via clutch input shaft (1).

This causes low range planetary gears (18) to rotate around sun gear (20) while rotating on their own axis.

This forces the carrier to rotate. Since the low range planetary carrier and 3rd speed planetary carrier are one piece, the 3rd speed planetary gears (22) also rotate around sun gear.

20

18 95ZV32006

22

When the 1st speed clutch is engaged, drop gear (32), 1st speed clutch gear (26), 3rd speed ring gear (23) and 3rd speed sun gear (24), 2nd speed sun gear (29), clutch output shaft (34) form one unit.

As a result, the rotation of 3rd speed planetary gear (22) around sun gear (24) is output as the rotation of drop gear (32).

The low range planetary decreases the speed of the input shaft but increases torque. The first speed clutch is used to directly transmit this high torque-low speed to the output shaft.

34

23 95ZV32007

fNOTE:

T3-8-12

Planetary gear (22) does not rotate on its own axis.

Ring gear (23) and output shaft (34) form one unit.

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Forward First Speed Power Flow Path Low range clutch and 1st speed clutch are engaged.

Low Range Clutch

Inlet of Low Range Clutch Oil

1st Speed Clutch Input Power Inlet of 1st Speed Clutch Oil

Output Power

115Z7-03-08-05

11517181920-

Clutch Input Shaft Anchor Pin Low Range Clutch Piston Low Range Planetary Gear Low Range Ring Gear Low Range Sun Gear

222324262931-

3rd Speed Planetary Gear 3rd Speed Ring Gear 3rd Speed Sun Gear 1st Speed Clutch Gear 2nd Speed Sun Gear 1st Speed Clutch Piston

T3-8-13

32333435-

Drop Gear 1st Speed Clutch Piston Return Spring Clutch Output Shaft Low/3rd Speed Planetary Gear Carrier

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Forward Second Speed Power Flow Path Low range clutch and 2nd speed clutch are engaged.

2nd Speed Clutch

Inlet of 2nd Speed Clutch Oil

Low Range Clutch Inlet of Low Range Clutch Oil

Input Power

Output Power 115Z7-03-08-06

Forward Third Speed Power Flow Path Low range clutch and 3rd speed clutch are engaged.

Low Range Clutch Inlet of 3rd Speed Clutch Oil

Inlet of Low Range Clutch Oil

3rd Speed Clutch Input Power

Output Power 115Z7-03-08-07

T3-8-14

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Forward Fourth Speed Power Flow Path High range clutch and 2nd speed clutch are engaged.

2nd Speed Clutch

Inlet of 2nd Speed Clutch Oil

High Range Clutch

Input Power

Inlet of High Range Clutch Oil

Output Power 115Z7-03-08-08

T3-8-15

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Reverse First Speed Power Flow Path Reverse clutch and 1st speed clutch are engaged.

Reverse Clutch Inlet of Reverse Clutch Oil

1st Speed Clutch

Input Power Inlet of 1st Speed Clutch Oil

Output Power 115Z7-03-08-09

Reverse Second Speed Power Flow Path Reverse clutch and 2nd speed clutch are engaged.

2nd Speed Clutch

Inlet of 2nd Speed Clutch Oil

Inlet of Reverse Clutch Oil

Reverse Clutch

Input Power

Output Power 115Z7-03-08-10

T3-8-16

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Reverse Third Speed Power Flow Path Reverse clutch and 2nd speed clutch are engaged.

3rd Speed Clutch Inlet of 3rd Speed Clutch Oil

Reverse Clutch

Inlet of Reverse Clutch Oil

Input Power

Output Power 115Z7-03-08-11

T3-8-17

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Transmission Control Valve The transmission control units consist of clutch solenoid valve assembly and clutch valve assembly.

These units send variable electric signals to seven proportional solenoid valves, which direct oil to the respective clutch packs, and select or shift speed shift and forward/reverse travel direction.

fNOTE: See page T3-8-2 for the valve location.

Clutch Solenoid Valve Assembly

K115V2U32001

123-

High Range Clutch Solenoid Valve Low Range Clutch Solenoid Valve Reverse Clutch Solenoid Valve

456-

1st Speed Clutch Solenoid Valve 2nd Speed Clutch Solenoid Valve 3rd Speed Clutch Solenoid Valve

T3-8-18

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Clutch Valve Assembly From clutch solenoid valve (P3, PH, P1)

From clutch solenoid valve (P2, PL, PR)

Orifice

A-A

B-B

Hydraulic Diagram K115V2J32013

123-

High Range Clutch Solenoid Valve Low Range Clutch Solenoid Valve Reverse Clutch Solenoid Valve

456-

1st Speed Clutch Solenoid Valve 2nd Speed Clutch Solenoid Valve 3rd Speed Clutch Solenoid Valve

T3-8-19

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Modulator Valve Unit When changing direction or speed, the modulation mechanism works to reduce the time required for clutch engagement (time lag).

This prevents the shock at clutch engagement, improves the work efficiency and durability of the power system, and to ensures the operator's comfort.

The modulation mechanism controls the clutch oil pressure rising time 2

To T/C

5

6

1

To T/C return line

4

7

To T/M lubrication line

3

To T/M solenoid valve (Control valve pilot) 1234-

Clutch Pressure Regulator Valve Proportional Relief Valve Priority Valve T/C Inlet Relief Valve

567-

From T/C gear pump (via line filter)

Check Valve (1) Check Valve (2) Direct Charge Valve

T3-8-20

115Z7-03-08-12

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit

5

6 2

1

3

4

7

3 4

115Z7-03-08-13

1234-

Clutch Pressure Regulator Valve Proportional Relief Valve Priority Valve T/C Inlet Relief Valve

567-

Check Valve (1) Check Valve (2) Direct Charge Valve

T3-8-21

SECTION 3 COMPONENT OPERATION Group 8 Drive Unit Accumulator Two accumulators are installed between the proportional relief valve and the clutch valve assembly.

One is for the reverse clutch and the 1st speed clutch. The other is for the high range clutch, low range clutch, 2nd speed clutch and 3rd clutch.

Limit switch Limit switch (9) is built-in the accumulators, and is turned ON when the accumulator is fully filled up with the pressurized oil.

When limit switch (9) is turned ON, the MC determines the pressurization and starts gradually increasing the pressurizing current to proportional relief valve.

Initial Oil Charging into Clutch Piston Chamber In order to make the initial oil charging into the clutch piston chamber quickly, the accumulated oil (0.58 MPa (5.9 kgf/cm2) (84 psi)) in the accumulator is supplied to the clutch piston chamber first.

Accumulator Filling The torque converter gear pump supplies the oil to the clutch piston chamber and the accumulator simultaneously.

The torque converter gear pump continues to fill the oil into the accumulators and it also increases the oil pressure in the clutch piston chamber gradually.

115V2E32030

123-

Tube Piston Rod Cover

456-

Spring U-Packing O-Ring

789-

T3-8-22

Wear Ring Socket Bolt Limit Switch

SECTION 3 COMPONENT OPERATION Group 9 Axle Outline Axle consists of differential (3), final drive (2), axle shaft (1), service brake (4), and other driveline parts.

2

Power from the transmission is transmitted to the front axle and the rear axle through the propeller shaft. Inside the axle, power is transmitted to differential (3), and divided to the left and right sides, and drives axle shaft (1) and the wheels through final drive planetary (2).

1

3 115Z7-03-09-01

1-

Axle Shaft

2-

Final Drive (Planetary)

3-

T3-9-1

Differential

SECTION 3 COMPONENT OPERATION Group 9 Axle Front Axle Assembly Front Axle Disassembled View - 1 Refer to the following sections for the differential.

A

Front Differential (A side only)

115Z7-03-09-02

123456789101112131415-

Differential Assembly (Front) Plane Washer Bolt Plug Seal Washer Magnet Plug Screw Bleed Axle Housing Axle Housing Extension Sensor Temperature Bolt Plug O-Ring Seal Washer Spring Pin

161718192021222324252627282930-

Ring O-Ring Floating Seal Axle Shaft Taper Roller Bearing Wheel Hub Taper Roller Bearing O-Ring U-Nut Plane Washer Spring Internal Gear Hub D-Ring D-Ring Axle Nut

T3-9-2

3132333435363738394041-

Axle Washer Flanged Bolt Piston Socket Bolt Snap Ring Spring Pin Internal Gear Socket Bolt Bushing Spring Sleeve

SECTION 3 COMPONENT OPERATION Group 9 Axle Front Axle Disassembled View - 2 Refer to the following section for the planetary drive and service brake.

Planetary Drive

Service Brake

115Z7-03-09-03

54243444546474849-

Seal Washer Separation Disc Friction Disc Separation Disc Wear Ring Gear Spring Pin Brake Backing Plate O-Ring

505152535455565758-

Socket Bolt Housing Magnet Plug Planet Pin Plate Wear Ring Needle Cage Planet Gear Bolt

59606162636465-

T3-9-3

Sun Gear Snap Ring Bushing Cover Assy O-Ring Seal Washer Bolt

SECTION 3 COMPONENT OPERATION Group 9 Axle Rear Axle Assembly Refer to the Front Axle Assembly for the components of axle assembly (9).

115Z7-03-09-05

12345678910-

Flanged Bolt Ring Packing Bushing Bolt Set Elbow Fitting (for Bleeding) Axle Support (Front) Differential Assembly (Rear) Axle Assembly (Rear) Flanged Bolt

11121314151617181920-

Shaft Plane Washer Bolt Snap Ring Packing Head Pin Axle Support (Rear) Bushing Wear Ring Plate

T3-9-4

21- Plate 22- Bolt

SECTION 3 COMPONENT OPERATION Group 9 Axle Planetary Drive The power from the differential gears is transmitted through the axles to the planetary gears, and tires to move the machine.

Planetary Gear Carrier

Internal Ring Gear

The planetary gear set consists of sun gear (59) at the center, four planet gears (57) located around it, a carrier (housing (51)) supporting the planet gears, and internal ring gear (37) around them.

This final planetary drive is used for gear reduction, to increase of drive output torque to the wheels in the power transmission.

Sun Gear Planet Gear 115Z7-03-09-04

T3-9-5

SECTION 3 COMPONENT OPERATION Group 9 Axle Differential Gear (Conventional Type) The differential enables the left and right drive wheels to rotate at different speeds while steering and traveling on uneven surfaces.

Front Differential Disassembled View - 1 (For jacking)

115Z7-03-09-06

1234567-

Taper Roller Bearing Spiral Bevel Gear Set Housing Assy Stud Bolt Straight Pin Nut Taper Roller Bearing

891011121314-

Bolt Plane Washer Straight Pin Bushing Bevel Gear Wear Ring Bevel Gear

15161718192021-

T3-9-6

Spider O-Ring Snap Ring Roller Bearing Spring Washer Bolt Plane Washer

22232425262728-

Bolt Plate Bolt Self-Locking Nut Housing Assy O-Ring Plug

SECTION 3 COMPONENT OPERATION Group 9 Axle Front Differential Disassembled View - 2 Refer to the following section for the parking brake.

Parking Brake

115Z7-03-09-07 123456789101112131415-

Bleed Screw Housing D-Ring D-Ring Piston O-Ring Straight Pin Rod O-Ring Back-Up Ring O-Ring Sleeve O-Ring Oil Seal Oil Seal

161718192021222324252627282930-

Spring Spring Housing Breather O-Ring Plug Housing Hose Band Cap Flange Yoke Nut Seal Washer Plug Bolt Socket Grease Nipple

313233343536373839404142434445-

T3-9-7

Bolt Flanged Bolt Flanged Spring Washer Nut Flanged Plane Washer Bolt O-Ring Shim Plug Seal Washer Housing Magnet Plug Ring Taper Roller Bearing O-Ring

4647484950515253545556-

Brake Backing Plate Spring Pin Plane Washer Bolt Bolt Socket Friction Disc Separation Disc Spring Pin Gear O-Ring

SECTION 3 COMPONENT OPERATION Group 9 Axle Rear Differential Disassembled View

(For jacking)

115Z7-03-09-08 1234567891011-

Taper Roller Bearing Spiral Bevel Gear Set Housing Assy Stud Bolt Straight Pin Nut Taper Roller Bearing Bolt Plane Washer Straight Pin Bushing

1213141516171819202122-

Bevel Gear Wear Ring Bevel Gear Spider O-Ring Snap Ring Roller Bearing Spring Washer Bolt Plane Washer Bolt

2324252627282930313233-

T3-9-8

Plate Bolt Self-Locking Nut Housing Assy O-Ring Plug Plane Washer Nut O-Ring Flange Yoke Bolt

34353637383940414243-

Breather Grease Nipple Trunnion Oil Seal Oil Seal O-Ring Sleeve Housing O-Ring Shim

SECTION 3 COMPONENT OPERATION Group 9 Axle Purpose of Differential 1. When the machine is steered, the inner wheel turns with a smaller radius, so the outer wheel needs to rotate faster for smooth steering.

2. Suppose driving the rear wheel by directly installing the gear to the propeller shaft with a shaft having no differential.

3. In this case, the outer wheel and the inner wheel rotate at the same rate. Therefore, when the machine is steered, the outer wheel cannot rotate more than the inner wheel. Consequently, axle strain, tire scuffing and wear takes place. In addition, due to axle shaft torsional stress and unstable transmission of drive force take place.

4. On the other hand, with a differential installed, the inner and the outer wheels can rotate at different speeds, and the problem mentioned above is eliminated.

a

b c T202-03-05-005 a-

Extension Line of Rear Wheel Centers

b-

While Turning the Machine

c-

T3-9-9

Traveling on Rough Surfaces

SECTION 3 COMPONENT OPERATION Group 9 Axle Function of Differential Gear 1. The power output from the engine is transmitted to the front and rear axle through the torque converter and the transmission.

2. The power is transmitted from pinion gear (1) to axle shaft (2) through bevel gear (5) and differential (4) in the axle housing.

3. Finally the power is transmitted to the planetary gears and tires to move the machine.

115K22005

T3-9-10

SECTION 3 COMPONENT OPERATION Group 9 Axle Operation of Differential Gear Straight When moving in a straight direction, each wheel holds the same amount of torque.

Therefore, pinion gears (4) in the differential assy do not turn.

Torque from carrier (6) is transmitted to each wheel equally through pinion gears (4), side gears (3) and axle shafts (2).

115ZV22013

Turn When turning, the inside wheel needs more torque than the outside wheel because of the resistance on it.

The outside wheel rotates faster than the inside wheel.

Then, pinions (4) turn on side gears (3) and torque from carrier (6) is transmitted to each wheel through pinion gears (4), side gears (3) and axle shafts (2)..

115ZV22014

T3-9-11

SECTION 3 COMPONENT OPERATION Group 9 Axle Limited Slip Differential (LSD) (Option) LSD (Limited-Slip Differential) is installed between side gear (1) and differential cage (2), and increases tractive effort.

If the surface traction of the right and left tires differ from each other during operation, LSD clutch (3) engages and prevents traction loss.

The performance of LSD is shown by using the bias ratio.

The bias ratio is the ratio between the driving force of the right and left tires while differential pinion (4) is turned.

When the bias ratio is larger, it is easier to gain traction on the ground surface with less resistance.

Side gear (1) moves to the left and pushes LSD clutch (3).

95V2E22014.

12-

Side Gear Differential Cage

34-

LSD Clutch Assembly Differential Pinion

T3-9-12

5-

Axle Shaft

SECTION 3 COMPONENT OPERATION Group 9 Axle Operation of LSD The following shows operation for the left tire.

1. A rotating driving force is transmitted from the differential cage via spider (cross shaft) to the differential pinion and the side gear.

2. When the ground surface resistance for the left tire lessens, the tapered interface between the differential pinion and the left side gear induces a side force.

3. It pushes the left side gear to the left resulting in frictional engagement with the differential cage, thus impeding free left side gear rotation and gaining traction.

Performance Comparison Between LSD and Conventional Differential

LSD differential point 0.5 (Bias ratio 2.0)

Torque

LSD

e On

ns spi tire

ge ran he t in tire One

Limited Slip Diff.

Conventional Diff. ange ting r opera

e ang he r t n si spin

TPD differential point 1.0 (Bias ratio 1.0)

Friction Ration Between Right and Left Tires

Torque is transferred to the right and left tires evenly until the friction ratio between the right and left tires comes to 0.5:1.

The result is that the LSD adds tractive effort.

A - Detail K115V2U22010

T3-9-13

SECTION 3 COMPONENT OPERATION Group 9 Axle Service Brake The type of service brake used is a enclosed wet-type multi-plate hydraulic brake and is assembled in the differential housing of the axle. All four wheels are equipped with this wet disc brakes.

When brake is applied 1. Oil from the pump is regulated in a range from 6.9~11.8 MPa (70~120 kgf/cm2) (995~1,706 psi) by the unloader valve, and accumulated in the accumulator provided for the front and rear wheels.

2. When the brake valves are depressed, the pressure oil in the accumulator enters the disc brake piston chamber for the front and rear wheels, pushes brake piston (1) that compresses brake friction plate (5), which is splined to axle shaft (7) via disc gear (6), and steel plate (4), which is fixed to the brake housing.

3. Thus the compressed plates slows rotation of the wheel by the friction (braking power).

When brake is released 1. While the brake pedal is not pressed, pressure from the brake valve is reduced, and brake piston (1) is returned by return spring (3).

2. Brake friction plates (5) are released to apply no braking.

Service Brake Pedal Stroke Adjustment Mechanism Even if the brake disc is worn, the integrated adjustment mechanism always adjusts for a constant pedal stroke.

1. When the brake discs (5) wear and brake piston (2) is shifted, sleeve (15) is gradually pushed out by socket bolt (13) by the amount corresponding to the wear.

2. When the brake pedal is released and the hydraulic pressure is not applied on brake piston(2), brake piston (2) is pulled back by return spring (3) and stopped by sleeve (15). Thus, the brake piston return amount is kept constant.

fNOTE: Sleeve (15) movement is regulated by tolerance ring (spring) (14) and is not moved by piston return spring (3) force.

T3-9-14

SECTION 3 COMPONENT OPERATION Group 9 Axle

Piston Stroke Adjuster

Brake Oil Inlet Port

Axle Housing Wheel Hub

115Z7-03-09-09 123456-

Internal Gear Hub Brake Piston Piston Return Spring Steel Plate Friction Plate Disc Gear

789101112-

Axle Shaft O-Ring (for Brake Piston) O-Ring (for Brake Piston) O-Ring (for Gear Hub) O-Ring (for Gear Hub) Air Bleeder Nipple

T3-9-15

13141516-

Socket Bolt Tolerance Ring Sleeve Bushing

SECTION 3 COMPONENT OPERATION Group 9 Axle Parking Brake The parking brake is the spring applied oil pressure released type.

Turning on the parking switch turns off the solenoid valve for parking, returns the oil in the brake piston chamber to the tank, pushes piston (1) with springs (2, 3), and makes the brake effective.

Turning off the parking switch turns on the solenoid valve for parking, oil flows into the piston chamber, pushes piston (1) to the upward overcoming spring force (2, 3), and release the brake.

2 3

4 5 Brake Oil

1

115Z7-03-09-10 123-

Piston Spring Spring

45-

Friction Disc Separation Disc

T3-9-16

SECTION 3 COMPONENT OPERATION Group 9 Axle Parking Brake Manual Release If the park brake cannot be released due to an electrical problem, such as a failed park brake solenoid valve coil or electrical circuit, perform the following operation.

fNOTE: After contacting with housing (9), approximately

1. Remove the lock bolt on the front differential and remove the flange nuts from both parts (A).

3 or 4 additional turns of the flange nuts will release the parking brake.

2. Loosen hose band (6) and remove rubber cap (7) from manual release bolt (8).

3. Install the flange nuts, which were removed at step 1, to manual release bolt (8).

4. Tighten the flange nuts alternately and evenly until contacting with housing (9).

5. Then, tighten the flange nuts until you feel the nuts are rather tight; the brake is released.

Top

6

7

9 8 A

A

Lock Bolt Flange Nut

Detail of A 67-

Hose Bank Rubber Cap

89-

Parking Brake Manual Release Bolt Housing

T3-9-17

115Z7-03-09-10

SECTION 3 COMPONENT OPERATION Group 9 Axle (Blank)

T3-9-18

SECTION 3 COMPONENT OPERATION Group 10 Brake Valve Outline Brake valve (3) supplies pressurized oil stored in the brake accumulators to apply brake pressure in proportion to the position of brake pedals (1, 2).

The oil is supplied to the front and rear axle service brakes.

(Refer to SYSTEM / Hydraulic System.)

The brake valve consists of two independent systems.

When the right side pedal is depressed, the movement of right side pedal is transmitted to the left side pedal by the linkage and brake is applied. But the left side pedal is depressed, only left pedal works.

fNOTE: When the declutch position switch is

ON, depressing the left side pedal disengages the transmission while applying the service brake. Refer to the Operation and Maintenance Manual for the declutch position switch.

95TNED-03-09-01

1-

Brake Pedal

2-

Brake and Declutch Pedal

3-

T3-10-1

Brake Valve

SECTION 3 COMPONENT OPERATION Group 10 Brake Valve Brake Valve Component Layout

115TNED-03-09-04

T- Tank Port (To Hydraulic Tank) PR- Accumulator Port (From Unloader Valve via Reducing Valve Block ACC2 Port) PF- Accumulator Port (From Unloader Valve via Reducing Valve Block ACC1 Port)

Pi- Pilot Port (For Auto Brake) AR- Rear Brake Port (To Rear Axle) AF- Front Brake Port (To Front Axle)

12345678910-

111213141516171819-

115TNED-03-09-06

T3-10-2

Brake Pedal Seat Pedal Stopper Push Rod Pilot Piston Retainer Piston Return Spring Rod Control Spring Control Spring

Spool Spool Return Spring Plunger Retainer Balance Spring Spool Plunger Spool Return Spring Retainer

SECTION 3 COMPONENT OPERATION Group 10 Brake Valve (Blank)

T3-10-3

SECTION 3 COMPONENT OPERATION Group 10 Brake Valve Service Brake Operation While the Valve Is Not Operating 1. Oil sent from the pump is stored in the accumulators, and sent to the in-ports A1 and A2.

2. Piston (5) is pushed up to the non-operation position by springs (7, 9) via retainer (6).

3. The passages (b) and (d) (out-ports AR and AF) are closed by spools (11, 16), and pressurized oil from the accumulators via ports PR and PF are blocked.

4. Now oil in the brake piston chamber is sent into the inside of the valve, and returned to the tank from the tank port T. 5. As a result, the pressure inside the brake piston chamber becomes equivalent to the pressure in the tank.

115Z7-03-10-01

T3-10-4

SECTION 3 COMPONENT OPERATION Group 10 Brake Valve While the Valve Is Operating 1. When brake pedal (1) is pressed, push rod (4) and pilot piston (5) are pushed by seat (2).

2. Spools (11, 16) are pushed down by way of the spring pack via rod (8).

3. As a result, passages (a) and (c) and tank port T are closed.

4. When the spools (11, 16) are pushed down further, passages (b) and (d) are opened and pressure oil from the accumulator is sent to the brake piston chamber to apply the brake.

5. At this time, the brake line pressure acts on the reaction chamber inside the spools (11, 16) through the orifices (X, Y). As a result, the pressure in the reaction chamber works as a force to return the spools (11, 16) upward.

6. When the pressure in the reaction chamber becomes balanced with the spring load, it returns the spools (11, 16) to close the passages PR-AR and PF-AF to hold the pressure. By this operation, the brake pressure in proportion to the pedal pressing force is obtained, and the spring load by deflection are transmitted to the operator as pedal pressing force.

115Z7-03-10-02

T3-10-5

SECTION 3 COMPONENT OPERATION Group 10 Brake Valve Auto Brake Operation 1. When the conditions to activate the auto brake are satisfied, pressurized oil is supplied into the pilot chamber.

2. Piston (5) is pushed down in proportion to the pilot pressure, which generates the secondary pressure to apply brake (auto brake).

3. When the pressure in the pilot chamber decreases, piston (5) is pushed back by the spring.

4. Then, the secondary pressure is released to the tank port T, and auto brake is released.

Pilot Chamber

Pilot Pressure

115Z7-03-10-03

T3-10-6

SECTION 3 COMPONENT OPERATION Group 11 Others Propeller Shaft The engine power is transmitted to the torque converter, the first propeller shaft, the transmission, and is then transmitted to the second and third propeller shafts to the front and the rear axle.

The second propeller shaft uses a universal joint and slip joint type spline shaft for smooth power transmission at any steering angle or change in propeller shaft length.

The first and third propeller shafts are the fixed type with universal joints.

Transmission

Torque Converter

1

Front Differential

2

4

5

Rear Differential

3

115Z7-03-11-02

12-

First Propeller Shaft Second Propeller Shaft

34-

Third Propeller Shaft Pillow Block

T3-11-1

5-

Slip Joint

SECTION 3 COMPONENT OPERATION Group 11 Others 1st Propeller Shaft (Between Torque Converter and Transmission)

1

2

1

Grease nipple (a, b) installation angle

45°

Z View Z

Torque Converter

2

1 a 1

b

Transmission 95V2U22003-Z7

12-

Journal Spider Assembly Coupling Yoke

T3-11-2

SECTION 3 COMPONENT OPERATION Group 11 Others 2nd Propeller Shaft (Between Front Axle and Transmission)

2

1

1

5

Grease nipple (a, b, c, d) installation angle

1

45° Z

View Z 1

d

3

4 4

3 2 b

Front Differential

Transmission

5

1

c a 1 123-

Journal Spider Assembly Propeller Shaft Assembly Pillow Block

45-

Spline Yoke Sleeve Yoke Assembly

T3-11-3

115V2U22003-Z7

SECTION 3 COMPONENT OPERATION Group 11 Others 3rd Propeller Shaft (Between Transmission and Rear Axle)

1

2

Grease nipple (a, b) installation angle

1

45°

View Z

2

1 1

Rear Differential

b

Transmission 115V2U22004-Z7

a 1-

Journal Spider Assembly

2-

Propeller Shaft

T3-11-4

SECTION 3 COMPONENT OPERATION Group 11 Others Secondary Steering Pump (Option) The secondary steering pump is used when the oil from the main pump is suddenly stopped.

The secondary steering pump supplies pressure to the steering valve to permit the machine to move to a safe place.

The secondary steering pump consists of gear pump (2), electric motor (3), magnetic switch (4), and relief valve (1).

85V2E42052-Z7

1-

Relief Valve

2-

Gear Pump

3-

T3-11-5

Electric Motor

4-

Magnetic Switch

SECTION 3 COMPONENT OPERATION Group 11 Others Flow Regulator Valve

fNOTE: Refer to SYSTEM, Group 4 Hydraulic System for

The flow regulator valve is provided in the lift arm circuit and operated when the lift arm control lever is suddenly returned. This serves to modulate and buffer the rate of return to neutral of the lift arm spool, so that there is no perceived hydraulic shock on the machine.

Lift Arm/Bucket Control Circuit (page T2-4-18).

2

3

4 Multiple Control Valve

1

Front Chassis

115Z7-03-11-01

1-

Flow Regulator Valve

2-

Boom Raise Pilot Pressure Sensor (LU)

3-

T3-11-6

Bucket Roll Back Pilot Pressure Sensor (BT)

4-

Bucket Dump Pilot Pressure Sensor (BD)

SECTION 3 COMPONENT OPERATION Group 11 Others Operation

4. As pressure difference between front and rear of orifice (6) occurs, spool (5) moves to the left by pressure routed to the spring (3) side. Therefore, passage (2) in spool (5) is closed and pressurized oil from port A is blocked.

1. When the lift arm control lever is returned to neutral, returning oil from the spool in control valve is routed to port A. 2. Oil in port A flows to chamber (1) through orifice (6).

5. When passage (2) is closed, pressure in chamber (1) increases and spool (5) moves to the right. Passage (2) is open again and pressurized oil flows to port B.

3. Pressure in chamber (1) is routed to port B through passage (2) in spool (5), so that pressure in chamber (1) decreases.

6. By repeating step 3 to step 5, pressurized oil returns to the port B side gradually, and this regulates this spool return oil flow so that the spool in control valve is slowly returned.

B A4

A3

A2

A1

4

3

2 1

X

B2

B1

6 B4

5

B3

X A

A-

Port A

B-

Port B

12-

Chamber Passage

34-

Spring Housing

56-

T3-11-7

Spool Orifice

115Z7-03-11-03

SECTION 3 COMPONENT OPERATION Group 11 Others Ride Control Valve (Option)

fNOTE: Refer to pages T2-2-62 and T2-4-48 for the ride

The ride control valve consists of pressure reducing valve spool (1), plunger (2), and switching valve spool (3) controlled by proportional solenoid valve (4).

control system operation.

fNOTE: Ride control selector valve is mounted on the multiple control valve (Refer to page T3-2-28).

90Z7-03-11-02 1-

Pressure Reducing Valve Spool

2-

Plunger

3-

T3-11-8

Switching Valve Spool

4-

Proportional Solenoid Valve

SECTION 3 COMPONENT OPERATION Group 11 Others Ride Control Circuit Diagram

Multiple Control Valve

Ride Control Valve

95Z7-03-11-03

a-

From Main Pump

b-

From Accessory Pump

13-

Pressure Reducing Valve Spool Switching Valve Spool

45-

Proportional Solenoid Valve Ride Control Accumulator

67-

T3-11-9

Ride Control Selector Valve Lift Arm (Boom) Cylinders

SECTION 3 COMPONENT OPERATION Group 11 Others Operation When Ride Control Is Not Working 1. Pressurized oil from the main pump flows to reducing valve spool (1). When the circuit pressure in the accumulator side is lower than the reducing valve set pressure, the oil flows to ride control accumulator charging port (ACC) through reducing valve spool (1).

2. When pushing down the lift arm due to machine vibration, the bottom side circuit pressure of the lift arm cylinder increases.

3. When the pressure in the lift arm cylinder bottom side circuit becomes higher than the reducing valve set pressure, the pressurized oil is blocked by the check valve.

fNOTE: If proportional solenoid valve (4) is energized,

pressure oil in the bottom side circuit of the lift arm cylinder flows through spool (3) and is accumulated in the ride control accumulator.

When Ride Control Is Working 1. When proportional solenoid valve (4) is energized while pressurized oil is being supplied to the PL port, reducing valve spool (1) is shifted to the left and closes the accumulator charging circuit.

2. Switching valve spool (3) moves left, and the passage between the ride control accumulator and the lift arm cylinder is connected. Pressurized oil is supplied to the base end of lift arm cylinder circuit.

T3-11-10

SECTION 3 COMPONENT OPERATION Group 11 Others When Ride Control Is Not Working

90Z7-03-11-04

When Ride Control Is Working

90Z7-03-11-05 1-

Pressure Reducing Valve Spool

2-

Plunger

3-

Switching Valve Spool

T3-11-11

4-

Proportional Solenoid Valve

SECTION 3 COMPONENT OPERATION Group 11 Others Ride Control Accumulator The ride control accumulator is installed in the ride control accumulation circuit.

High-pressure nitrogen gas is contained in the accumulator, and pressurized oil compresses the nitrogen gas through the piston.

The ride control system permits the base end of the lift arm cylinders to work the oil against the piston inside the nitrogen gas oil accumulator.

This reduces fore and aft pitching of the machine.

T4GB-03-08-009

T3-11-12

SECTION 3 COMPONENT OPERATION Group 11 Others (Blank)

T3-11-13

SECTION 3 COMPONENT OPERATION Group 11 Others Priority Hammer Valve Priority hammer valve is a 3-way flow control valve, with two outlet ports (A, B).

When demanded by energizing the solenoid cartridge, the "A" port supplies a priority pressure-compensated/ constant flow, while the "B" port releases all additional flow required through the LS system for activation of the other functions.

From the "A" line, an LS pressure signal is delivered to the load-sensing circuit to increase the pump flow in order to match the requirement.

An incorporated relief cartridge turns OFF the priority flow when the preset maximum priority pressure is exceeded.

All actuators powered by the "A" and "B" outlets can operate simultaneously, independently from the respective working pressures.

95Z7-03-11-04

PTAB-

From Unloader Valve To Tank To Loading Circuit To Fan Motor Circuit

LS- To Shuttle Valve (High Pressure Switching Valve for Accessory Pump Control)

12-

Relief Valve Check Valve

3-

T3-11-14

Solenoid Cartridge

SECTION 3 COMPONENT OPERATION Group 11 Others

3

LS

T

2 1 A

B

P Shuttle Valve

View Z

Z

Rear Chassis

115Z7-03-11-05

PT-

From Unloader Valve To Tank

AB-

To Loading Circuit To Fan Motor Circuit

12-

Relief Valve Check Valve

3-

Solenoid Cartridge

T3-11-15

LS- To Shuttle Valve (High Pressure Switching Valve for Accessory Pump Control)

SECTION 3 COMPONENT OPERATION Group 11 Others Priority Hammer Valve Operation Pressurized oil from the accessory pump supplied to the priority hammer valve is used to operate the loading circuit (via port A) and the fan circuit (via port B).

The priority flow from port A can be switched on and off by energizing or de-energizing solenoid cartridge (2).

When Solenoid Is Not Energized 1. Normally, chamber (3) of compensating spool (4) is drained to tank through solenoid cartridge (2), and, consequently, spool (4) is fully piloted to the left, against spring (7).

2. In this position, the spool blocks the flow to port A, all the oil is directed to port B.

When Solenoid Is Energized 1. The priority flow is activated when solenoid cartridge (2) is energized.

2. The priority pressure downstream restrictor (1) builds up in compensation chamber (3) and adds to the force of spring (7).

3. They push spool (4) into an intermediate position in order to deliver the requested priority flow to port A. 4. Spool (4), which is exposed to the inlet pressure at one end and to the priority pressure plus spring force at the opposite end, will position itself so that the pressure difference (equal to the DELTA P across restrictor (1)) balances exactly the force of spring (7), which is constant.

5. This provides a constant DELTA P across restrictor (1) and, consequently, the priority flow remains constant for a given restrictor opening, independently forms the working pressure.

fNOTE: Refer to page T2-2-26 "Lift Arm Multiplication Control".

T3-11-16

SECTION 3 COMPONENT OPERATION Group 11 Others When Solenoid Is Not Energized: All Oil Flow To Port B

95Z7-03-11-06

When Solenoid Is Energized: Oil Flow To Ports "A" and "B"

95Z7-03-11-07

12-

Restrictor Solenoid Cartridge

34-

Chamber Compensation Spool

56-

Adjusting Screw Relief Cartridge

T3-11-17

7-

Spring

SECTION 3 COMPONENT OPERATION Group 11 Others (Blank)

T3-11-18

INDEX 1st Propeller Shaft..................................... T3-11-2

Clutch Pack .............................................. T3-8-11

2nd Propeller Shaft.................................... T3-11-3

Clutch Solenoid Valve Assembly ............... T3-8-18

3rd Propeller Shaft .................................... T3-11-4

Clutch Valve Assembly.............................. T3-8-19 Clutch and Gear Train................................. T3-8-8

A

Combination Valve

Accelerator Pedal Failure Control ............... T2-2-6

(Brake Manifold Valve) .......................... T1-2-22

Accessory Circuit ......................................T2-5-53

(Manifold Block) ...................................... T3-7-4

Accessory Circuit (Key Switch: ACC) .......... T2-5-8

(Solenoid Valve Block)............................. T3-7-7

Accessory Pump .......................... T1-2-19, T3-1-8

Combined Electric and

Accessory Pump Structure and Function .... T3-1-9

Hydraulic Control Circuit........................ T2-2-85

Accumulator ..............................................T3-8-22

Combined Operation Circuit...................... T2-4-42

Air Conditioner Circuit ...............................T2-5-28

Combined Operation of Lift Arm Raise /

Alternator Operation ................................T2-5-16

Bucket Dump......................................... T2-4-42

Auto Brake Circuit .....................................T2-4-14

Combined Operation of Steering (Right) /

Auto Brake Control ....................................T2-2-48

Lift Arm Raise........................................ T2-4-44

Auto Brake Operation ................................T3-10-6

Control System, Outline .............................. T2-2-1

Auto Idling Stop Circuit ..............................T2-5-22

Control Valve Cross Section Views ............. T3-2-4

Auto Idling Stop Control.............................T2-2-80

Control Valve Overview............................... T3-2-3

Auto-Warm Up Control ............................... T2-2-8

Control Valve, Outline ................................. T3-2-1

Automatic Speed Shift Control ...................T2-2-36

Controller and Relays ................................. T1-2-7

Axle, Outline............................................... T3-9-1

Controller, Outline....................................... T2-1-1 Cooling Fan System Layout ........................ T3-3-1

B

Cross Section View of Transmission ......... T3-8-7

Base Torque Control..................................T2-2-22 Bleed-Off Compensation Spool..................T3-2-14

D

Brake Charge Valve (Unloader Valve)......... T3-7-2

Declutch Control ....................................... T2-2-42

Brake Light Circuit.....................................T2-5-46

Differential Gear (Conventional Type) ......... T3-9-6

Brake Priority Circuit .................................. T2-4-4

Downshift Control ..................................... T2-2-38

Brake Valve Component Layout.................T3-10-2

Drive Unit Hydraulic Circuit Diagram ........... T3-8-3

Brake Valve, Outline ..................................T3-10-1

Drive Unit, Outline ...................................... T3-8-1

Bucket Auto Leveler Control ......................T2-2-86 Bucket Dump Operation ............................T3-2-18

E

Bucket Roll Back Operation ........ T2-4-40, T3-2-16

ECM System, Outline.................................. T2-3-1

Bucket Spool .............................................T3-2-16

EGR Control ............................................. T2-3-10 Electric Component Layout

C

(Front Chassis) ....................................... T1-2-4

Cab Light Circuit........................................T2-5-62

(Rear Grill) .............................................. T1-2-5

CAN Circuit .................................... T2-1-2, T2-5-6

Electric Power Circuit (Key Switch: OFF) .... T2-5-4

Charging Circuit (Key Switch: ON).............T2-5-14

Electrical Component, Specifications ........ T1-3-11

Charging Circuit, Outline ............................ T3-7-1

Electrical Main Circuit ................................. T2-5-2

Clutch Combination .................................... T3-8-9

(i)

115Z7 F&S

INDEX Front Axle Assembly ................................... T3-9-2

Electrical System (Around Battery Box) .............................T1-2-12

Front Axle Disassembled View .................. T3-9-2

(Around Fuel Tank) ................................T1-2-14

Front Differential Disassembled View.......... T3-9-6

(Around Hydraulic Tank).........................T1-2-13

Front Wiper Circuit.................................... T2-5-56

(Cab) ...................................................... T1-2-6

Fuel Injection Control.................................. T2-3-2

Outline .................................................... T2-5-1

Fuel Injection Pressure Control ................... T2-3-6

(Rear Chassis Center Frame) ................T1-2-15

Fuel Injection Rate and Frequency Control . T2-3-8

Engine.......................................................T1-2-16

Fuel Injection Timing Control ...................... T2-3-8

Specifications.......................................... T1-3-1

Fuel Injection Volume Control ..................... T2-3-4

Engine Accessories, Specifications............. T1-3-4

Function of Differential Gear ..................... T3-9-10

Engine Control ........................................... T2-2-4 H

Engine Protection Control..........................T2-2-18

Hazard Light Circuit (Key Switch: OFF)..... T2-5-38

Engine Speed Regulator For Digging.........T2-2-10

Head Light Circuit ....................... T2-5-32, T2-5-34

Engine Stop Circuit....................................T2-5-24

High-Beam Circuit .................................... T2-5-36

Exhaust Filter ............................. T1-2-17, T2-3-14

Horn Circuit (Key Switch: OFF) ................. T2-5-42

Exhaust Filter Auto Regeneration Control ..T2-2-60

Hydraulic Circuit ......................................... T3-2-6

Exhaust Filter

Hydraulic Component, Specifications .......... T1-3-6

Manual Regeneration Control.................T2-2-58

Hydraulic Main Circuit, Outline.................. T2-4-22

Exhaust Filter Regeneration Control ..........T2-3-16

Hydraulic Pump ........................................ T1-2-18

Exhaust Filter

Hydraulic Pump, Outline ............................. T3-1-1

Regeneration Control Circuit ..................T2-4-46

Hydraulic System, Outline........................... T2-4-1 F I Increasing and Decreasing Flow Rate ............. T3-1-4

Fan Circuit ................................................T2-4-20 Fan Control Valve....................................... T3-3-3 Fan Control, Valve Control.........................T2-2-51

J

Fan Motor................................................... T3-3-2

Joystick Steering Control Valve ................... T3-4-6

Fan Pump (Accessory Pump) ..................... T3-3-1

Joystick Steering Control Valve Operation... T3-4-8

Fan Reverse Rotation Control ...................T2-2-54

Joystick Steering Controls......................... T1-2-11

Fan Speed Control ....................... T2-2-52, T3-3-9

Joystick Type Pilot Valve

Fingertip Control Type Pilot Valve

Electromagnetic Detent ......................... T3-6-16

Electromagnetic Detent ........................... T3-6-6

Operation ................................................ T3-6-9

Operation................................................ T3-6-2

Outline .................................................... T3-6-7

Outline .................................................... T3-6-1 Flow Amplifier Notch and Pilot Orifice ........T3-5-20

L

Flow Rate Control Circuit...........................T2-4-34

Lift Arm (Boom) / Bucket Operation Control Circuit ....................................... T2-4-16

Flow Rate Control Operation .....................T3-2-26

Lift Arm (Boom) Auto Leveler

Flow Regualtor Valve...................T1-2-23, T3-11-6 Operation............................................... T3-11-7

Height Kickout Control........................... T2-2-74

Forward/Reverse Switch Activation Control ...........

Lower Kickout Control ........................... T2-2-76

T2-2-32 (ii)

115Z7 F&S

INDEX Lift Arm (Boom) Down Operation ...............T3-2-22

Multiple Control Valve ............................... T1-2-21

Lift Arm (Boom) Float Operation ................T3-2-24

Multiple Control Valve Hydraulic Circuit....... T3-2-2

Lift Arm (Boom) Raise Operation ...............T3-2-20

Multiple Control Valve Location ................... T3-2-1

Lift Arm (Boom) Spool................................T3-2-20 N

Lift Arm Float Control.................................T2-2-88

Neutral Circuit........................................... T2-4-34

Lift Arm Flow Rate Control Valve ...............T3-2-26

Neutral Control ......................................... T2-2-30

Lift Arm Speed Multiplication Control .........T2-2-26

Neutral Engine Start Circuit....................... T2-5-12

Lift Arm and Bucket Selection

Normal Rotation, Fan.................................. T3-3-4

Circuit Control ........................................T2-2-56 Light Switch: Tail ( | ) Position....................T2-5-32

O

Limit switch, Accumulator ..........................T3-8-22

Operation of Differential Gear ................... T3-9-11

Limited Slip Differential (LSD) (Option) ......T3-9-12

Operation of LSD ...................................... T3-9-13

Load-Free Engine High Idle Limiter ...........T2-2-16

Operation of Transmission .......................... T3-8-9

Lock Up Control ........................................T2-2-46

Other Circuits ........................................... T2-4-34

Low Brake Oil Pressure Indicator Control ..T2-2-70

Other Control............................................ T2-2-65

Low Steering Oil Pressure Indicator Control

Overload Relief Valve

(Option) .................................................T2-2-72

(with Make-Up Function) ....................... T3-2-10

M

P

Main Component

Parallel Circuit Flow Rate Control ............. T2-4-38

(Hydraulic System).................................. T1-2-3

Parking Brake ........................................... T3-9-16

(Overview) .............................................. T1-2-1

Parking Brake Circuit .................. T2-4-12, T2-5-48

(Power System) ...................................... T1-2-2

Parking Brake Manual Release ................. T3-9-17

Main Hydraulic Pump ................................. T3-1-2

Parking Brake Operation Indicator Control

Main Pump ................................................T1-2-18

............................................................. T2-2-68

Main Pump Cross Section .......................... T3-1-3

Pilot Circuit, Outline .................................... T2-4-2

Main Pump Hydraulic Diagram ................... T3-1-2

Pilot Shut-Off Circuit (Key Switch: ON) ..... T2-5-20

Main Relief Valve ....................................... T3-2-8

Planetary Drive ......................................... T3-9-5

Make-Up Function, Fan Circuit ..................T3-3-10

Power Flow Path in the Transmission ....... T3-8-12

Make-Up Operation, Overload Relief Valve

Preheating Control.................................... T2-3-12

..............................................................T3-2-12

Priority Hammer Valve .............................T3-11-14

Make-Up Valve Operation..........................T3-5-16

Operation .............................................T3-11-16

Manual Speed Shift Control .......................T2-2-34

Propeller Shaft.......................................... T3-11-1

Meter-in Compensation Spool Operation .... T3-5-9

Proportional Solenoid Valve ........................ T3-7-8

Modulator Valve Unit ...............................T3-8-20

Pump Control ........................................... T2-2-21

Monitor Circuit ...........................................T2-5-27

Pump Control Circuit................................. T2-4-36

Monitor Panel ............................................T1-2-10

Pump Control Valve

Monitor and Switches ................................. T1-2-9

(Negative Control Relief Valve).............. T3-2-30

Multi-Function Monitor /

Pump Delivery Pressure Sensor ............... T3-1-10

Air Conditioner Switch Panel .................. T1-2-11

Purpose of Differential ................................ T3-9-9

(iii)

115Z7 F&S

INDEX Q Quick Power Mode Control............................. T2-2-78

Speed Limit Control with Power Mode OFF

R

Speed Shift Delay Control ......................... T2-2-40

Rear Axle Assembly ................................... T3-9-3

Starting Circuit (Key Switch: START) ........ T2-5-10

Rear Differential Disassembled View .......... T3-9-8

Steering (Left Turn Position) ....................... T3-5-6

Rear Wiper Circuit .....................................T2-5-58

Steering (Right) Operation ........................ T2-4-30

Reducing Valve .......................................... T3-7-6

Steering Column Monitor Circuit ............... T2-5-31

Regulator ................................................... T3-1-5

Steering Main Relief Valve, Operation ....... T3-5-10

Regulator Control Function......................... T3-1-6

Steering Operation Control Circuit ............ T2-4-28

Relief Circuit .............................................T2-4-34

Steering Overload Relief Valve

............................................................. T2-2-12

Relief Operation, Main Relief Valve ............ T3-2-8

Function ................................................ T3-5-12

Relief Operation, Overload Relief Valve.....T3-2-10

Operation .............................................. T3-5-14

Reverse Light / Buzzer Circuit ...................T2-5-44

Steering Pilot Circuit and Its Operation ..... T3-5-18

Reverse Rotation, Fan................................ T3-3-6

Steering Pilot Line ...................................... T3-4-1

Ride Control (Option) ................. T2-2-62, T3-2-28

Steering Pilot Valve..................................... T3-4-4

Ride Control Accumulator ........................ T3-11-12

Operation ................................................ T3-4-4

Ride Control Circuit (Option)......................T2-4-48

Structure ................................................. T3-4-5

Ride Control Circuit Diagram ..................... T3-11-9

Steering Priority Circuit ............................. T2-4-24

Ride Control Selector Valve .....................T3-2-29

Steering Spool Variable Orifice.................. T3-5-17

Ride Control Valve (Option) .........T1-2-23, T3-11-8

Steering Stop Operation

Operation............................................. T3-11-10

(When Fully Turned Right)..................... T2-4-32

Right Console............................................. T1-2-8

Steering Valve .......................................... T1-2-22 Neutral Position....................................... T3-5-4

S

Outline .................................................... T3-5-1

Secondary Steering Circuit (Option)...........T2-4-50

Overview ................................................. T3-5-1

Secondary Steering Control (Option) .........T2-2-82

Steering Valve Cross Section View ............. T3-5-3

Secondary Steering Pump (Option)

Steering Valve Main Component ................. T3-5-2

................................................T1-2-23, T3-11-5

Steering Valve Meter-In Compensator......... T3-5-8

Service Brake............................................T3-9-14

Surge Voltage Prevention Circuit .............. T2-5-18

Service Brake Accumulator......................... T3-7-9

Switching from Normal to Reverse Rotation

Service Brake Circuit.................................T2-4-10

............................................................... T3-3-8

Service Brake Operation ...........................T3-10-4 T

Service Brake Pedal Stroke Adjustment Mechanism ..........................T3-9-14

Torque Converter (Lock-Up)........................ T3-8-4

Shift Holding Control .................................T2-2-44

Torque Decrease Control While Digging.... T2-2-24

Shift Pattern and Shift Position ..................T3-8-10

Traction Control ........................................ T2-2-14

Shock Dampening Function

Transmission Alarm Control ...................... T2-2-66

When Stopping Lift Arm Operation ........T2-4-18

Transmission Control ................................ T2-2-28

Single Operation Circuit.............................T2-4-40

Transmission Control Valve....................... T3-8-18

Specifications ............................................. T1-1-1

Transmission and Torque Converter Assembly ................................................. T1-2-20, T3-8-2 (iv)

115Z7 F&S

INDEX Transmission, Structure .............................. T3-8-6 Turn Signal Light Circuit ............................T2-5-40 U Unit Location, Steering Pilot ....................... T3-4-2 Unloader Valve (Brake Charge Valve)........T1-2-22 V Variable Turbocharger Control ...................T2-3-13 W Washer Circuit ...........................................T2-5-60 Wiper Circuit..............................................T2-5-56 Work Light Circuit ......................................T2-5-54

(v)

115Z7 F&S