Page 1

99739-66100

Service Manual GP40K, GP40KL, GP45K, GP50K; DP40K, DP40KL, DP45K, DP50K Chassis & Mast GP40K GP40KL GP45K GP50K

ET29B-00011-up ET29B-50001-up ET29B-80001-up ET33A-50001-up

DP40K DP40KL DP45K DP50K

ET19C-00011-up ET19C-50001-up ET19C-80001-up ET28B-50001-up

For use with GM4.3L, S6S Engine Service Manual


FOREWORD

This service manual is a guide to servicing of CaterpillarŽ Lift Trucks. The instructions are grouped by systems to serve the convenience of your ready reference. Long productive life of your lift trucks depends to a great extent on correct servicing – the servicing consistent with what you will learn from this service manual. We hope you read the respective sections of this manual carefully and know all the components you will work on before attempting to start a test, repair or rebuild job. The descriptions, illustrations and specifications contained in this manual were of the trucks of serial numbers in effect at the time it was approved for printing. Caterpillar reserves the right to change specifications or design without notice and without incurring obligation. GP40K, GP40KL, GP45K, and GP50K are powered by GM4.3L gasoline engine. DP40K, DP40KL, DP45K, and DP50K are powered by Mitsubishi S6S diesel engine.

Safety Related Signs The following safety related signs are used in this service manual to emphasize important and critical instructions: WARNING

Indicates a specific potential hazard resulting in serious bodily injury or death.

CAUTION

Indicates a specific potential hazard resulting in bodily injury, or damage to, or destruction of, the machine.

NOTE

Indicates a condition that can cause damage to, or shorten service life of, the machine.

Pub. No. 99739-66100


HOW TO READ THIS MANUAL Disassembly diagram (example)

Each disassembly diagram is followed by Disassembly sequence and Suggestions for disassembly.

Disassembly sequence Sequence 1. Cover, Bolt, Washer (part name) 2. Output shaft (part name)

Suggestion for disassembly (1) Output shaft removal Unit: mm (in.) A

0.020 to 0.105 (0.00079 to 0.00413)

B

0.15 (0.0059)

Clearance between cylinder and piston

A: Standard value

Symbols or abbreviations OP ...................Option R1/4.................Taper pipe thread (external) 1/4 inch (formerly PT1/4) Rc1/8 ...............Taper pipe thread (internal) 1/8 inch (formerly PT1/8) G1/4A..............Straight pipe thread (external) 1/4 inch (formerly PF1/4-A) Rp1/8...............Straight pipe thread (internal) 1/8 inch (formerly PS1/8)

B: Repair or service limit


WARNING

SAFETY WARNING

WARNING

The proper and safe lubrication and maintenance for this lift truck, recommended by Caterpillar, are outlined in the OPERATION & MAINTENANCE MANUAL for these trucks.

Do not operate this truck unless you have read and understand the instructions in the OPERATION & MAINTENANCE MANUAL. Improper truck operation is dangerous and could result in injury or death.

Improper performance of lubrication or maintenance procedures is dangerous and could result in injury or death. Read and understand the OPERATION & MAINTENANCE MANUAL before performing any lubrication or maintenance.

4. Lower the forks or other implements to the ground before performing any work on the truck. If this cannot be done, make sure the forks or other implements are blocked correctly to prevent them from dropping unexpectedly.

The serviceman or mechanic may be unfamiliar with many of the systems on this truck. This makes it important to use caution when performing service work. A knowledge of the system and/or components is important before the removal or disassembly of any component.

5. Use steps and grab handles (if applicable) when mounting or dismounting a truck. Clean any mud or debris from steps, walkways or work platforms before using. Always face truck when using steps, ladders and walkways. When it is not possible to use the designed access system, provide ladders, scaffolds, or work platforms to perform safe repair operations.

Because of the size of some of the truck components, the serviceman or mechanic should check the weights noted in this Manual. Use proper lifting procedures when removing any components. Following is a list of basic precautions that should always be observed. 1. Read and understand all warning plates and decals on the truck before operating, lubricating or repairing the product. 2. Always wear protective glasses and protective shoes when working around trucks. In particular, wear protective glasses when pounding on any part of the truck or its attachments with a hammer or sledge. Use welders gloves, hood/goggles, apron and other protective clothing appropriate to the welding job being performed. Do not wear loose-fitting or torn clothing. Remove all rings from fingers when working on machinery. 3. Do not work on any truck that is supported only by lift jacks or a hoist. Always use blocks or jack stands to support the truck before performing any disassembly.

6. To avoid back injury, use a hoist when lifting components which weigh 23 kg (50 lb.) or more. Make sure all chains, hooks, slings, etc., are in good condition and are of the correct capacity. Be sure hooks are positioned correctly. Lifting eyes are not to be side loaded during a lifting operation. 7. To avoid burns, be alert for hot parts on trucks which have just been stopped and hot fluids in lines, tubes and compartments. 8. Be careful when removing cover plates. Gradually back off the last two bolts or nuts located at opposite ends of the cover or device and pry cover loose to relieve any spring or other pressure, before removing the last two bolts or nuts completely. 9. Be careful when removing filler caps, breathers and plugs on the truck. Hold a rag over the cap or plug to prevent being sprayed or splashed by liquids under pressure. The danger is even greater if the truck has just been stopped because fluids can be hot.


10. Always use tools that are in good condition and be sure you understand how to use them before performing any service work. 11. Reinstall all fasteners with same part number. Do not use a lesser quality fastener if replacements are necessary. Do not mix metric fasteners with standard nuts and bolts. 12. If possible, make all repairs with the truck parked on a level, hard surface. Block truck so it does not roll while working on or under truck. 13. Disconnect battery and discharge any capacitors (electric trucks) before starting to work on truck. Hang “Do not Operate� tag in the Operator’s Compartment. 14. Repairs, which require welding, should be performed only with the benefit of the appropriate reference information and by personnel adequately trained and knowledgeable in welding procedures. Determine type of metal being welded and select correct welding procedure and electrodes, rods or wire to provide a weld metal strength equivalent at least to that of parent metal. 15. Do not damage wiring during removal operations. Reinstall the wiring so it is not damaged nor will it be damaged in operation by contacting sharp corners, or by rubbing against some object or hot surface. Do not connect wiring to a line containing fluid. 16. Be sure all protective devices including guards and shields are properly installed and functioning correctly before starting a repair. If a guard or shield must be removed to perform the repair work, use extra caution. 17. Always support the mast and carriage to keep carriage or attachments raised when maintenance or repair work is performed, which requires the mast in the raised position.

18. Loose or damaged fuel, lubricant and hydraulic lines, tubes and hoses can cause fires. Do not bend or strike high pressure lines or install ones which have been bent or damaged. Inspect lines, tubes and hoses carefully. Do not check for leaks with your hands. Pin hole (very small) leaks can result in a high velocity oil stream that will be invisible close to the hose. This oil can penetrate the skin and cause personal injury. Use cardboard or paper to locate pin hole leaks. 19. Tighten connections to the correct torque. Make sure that all heat shields, clamps and guards are installed correctly to avoid excessive heat, vibration or rubbing against other parts during operation. Shields that protect against oil spray onto hot exhaust components in event of a line, tube or seal failure, must be installed correctly. 20. Relieve all pressure in air, oil or water systems before any lines, fittings or related items are disconnected or removed. Always make sure all raised components are blocked correctly and be alert for possible pressure when disconnecting any device from a system that utilizes pressure. 21. Do not operate a truck if any rotating part is damaged or contacts any other part during operation. Any high speed rotating component that has been damaged or altered should be checked for balance before reusing.


GENERAL INFORMATION

Model View

103235

Truck Models Covered This Service Manual furnishes servicing and maintenance information for the following trucks: Truck model

Model code – Serial number

Engine mounted

GP40K

ET29B – 00011- up

GM4.3L gasoline engine

GP40KL

ET29B – 50001- up

GM4.3L gasoline engine

GP45K

ET29B – 80001- up

GM4.3L gasoline engine

GP50K

ET33A – 50001- up

GM4.3L gasoline engine

DP40K

ET19C – 00011- up

Mitsubishi S6S diesel engine

DP40KL

ET19C – 50001- up

Mitsubishi S6S diesel engine

DP45K

ET19C – 80001- up

Mitsubishi S6S diesel engine

DP50K

ET28B – 50001- up

Mitsubishi S6S diesel engine

1-1


GENERAL INFORMATION

Serial Number Locations

Chassis serial number Name plate

(Gasoline- and LP-Gasengine models)

(Diesel-engine models)

(Gasoline- and LP-Gas-engine models)

Mast serial number

Transmission serial number

(Diesel-engine models)

Engine serial number

208804

1-2


GENERAL INFORMATION

Chassis and Mast Model Identification

[Chassis] GP

40

K

Generation designator

Maximum capacity/Load center 40: 4000 kg (8000 lb)/500 mm (20 in.) 40L: 4000 kg (8000 lb)/600 mm (24 in.) 45: 4500 kg (10000 lb)/600 mm (24 in.) 50: 5000 kg (11000lb)/600 mm (24 in.) Engine type GP: gasoline engine type DP: diesel engine type [Mast] 4

V

40

A

33

Maximum lifting height [“33” stands for 3300 mm (130 in.)] Order of the minor change (“A” for the original, “B” for the first change, “C” for the second change, and so on) Applicable truck model designation 40: 4 ton class 40L: 4 ton class 45: 4.5 ton class 50: 5 ton class Kind of mast V: simplex mast F: duplex mast M: triplex mast Major change (“2” for the original, “3” for the first change, and so on up to “9”) 1-3


GENERAL INFORMATION

Dimensions

G

K

C

L

E J

A

I

H B

P

D

N

M

O

F

202762A

1-4


GENERAL INFORMATION

Unit: mm (in.) Ref. No. Item

Truck Model

A

Maximum lift

B

Free lift

C

Fork spread (outside)

D

Fork length

E

Tilt angle (forward – backward)

F

Overall length

G

Overall width (outside of tires)

GP40K DP40K

150 (5.9)

6° – 10° 4290 (168.9)

Overall height (to top of mast lowered)

I

Overall height (to top of overhead guard)

J

Overall height (mast extended)

K

Tread (front)

Wheelbase

N

Front overhang

O

Rear overhang

P

Underclearance (at frame)

160 (6.5)

1220 (48)

H

M

GP50K DP50K

300 to 1190 (12 to 47)

4340 (170.9)

1415 (55.7)

Dual tire

Tread (rear)

GP45K DP45K

3300 (130)

Single tire

L

GP40KL DP40KL

4395 (173.0)

4525 (178.2)

1460 (57.5) 1780 (70.1)

1965 (77.4)

2320 (91.5)

2400 (94.5) 2250 (88.6)

4430 (174.4)

4580 (180.5)

Single tire

1175 (46.5)

Dual tire

1310 (51.5) 1180 (46.5) 2000 (78.5) 557 (21.9) 513 (20.6)

563 (22.6)

2150 (84.5) 562 (22.1)

582 (22.9)

613 (24.4)

573 (22.6)

252 (9.9)

1-5


GENERAL INFORMATION

Technical Data Truck Model Item

GP40K DP40K

GP40KL DP40KL

Model code

GP45K DP45K

GP: ET29B DP: ET19C

Type

General

Maximum lift

4000/500 (8000/20)

4000/600 (8000/24)

mm (in.)

Lift speed (rate load) mm/sec (fpm)

GP: 510 (100) DP: 500 (98)

GP: 440 (87) DP: 430 (85) 500 (100)

Tilt angle (forward – backward)

6° – 10°

mm (in.)

Minimum turning radius mm (in.)

5000/600 (11000/24)

3300 (130)

Travel speed of Forward powershift transmission models km/h (mph) Reverse Performance

4500/600 (10000/24)

Lowering speed (rate load) mm/sec (fpm)

Free lift

2735 (107.7)

GP: 430 (85) DP: 420 (83)

150 (5.9)

160 (6.5)

19.5 (12)

23.5 (15)

19.5 (12)

23.5 (15)

2775 (109.3)

Inside

2820 (111)

2965 (116.7)

83°

Steering angle Outside Minimum Single tire intersecting aisle mm (in.) Dual tire Front tires (size and inflation pressure)

Tires

GP: ET33A DP: ET28B Standard

Capacity/load center kgf/mm (lbf/in.)

kPa (kgf/cm2) [psi]

Single tire

56°33’ 2390 (94.1)

2430 (95.7)

2450 (96.5)

2510 (98.8)

2570 (101)

2590 (102)

2620 (103)

2670 (105)

8.25-15-14PR (I) 785 (8.0) [114]

300-15-18PR (I) 785 (8.0) [114] 7.50-16-12PR (I) 686 (7.0) [99.5]

Dual tire

Rear tires (size and inflation pressure) kPa (kgf/cm2) [psi] Truck weight

GP50K DP50K

7.00-12-14PR (I) 686 (7.0) [99.5]

834 (8.5) [121]

Single drive tire (unloaded) GP: 5630 (12400) kg (lb) DP: 5710 (12600)

GP: 6030 (13300) DP: 6120 (13500)

GP: 6600 (14500) DP: 6680 (14700)

GP: 7080 (15600) DP: 7160 (15800)

Dual drive tire (unloaded) GP: 5810 (12800) kg (lb) DP: 5900 (13000)

GP: 6160 (13600) DP: 6250 (13800)

GP: 6730 (14800) DP: 6820 (15000)

GP: 7250 (15900) DP: 7320 (16100)

1-6


GENERAL INFORMATION

Truck Model GP40K

GP40KL

GP45K

Item Engine model

GM4.3L

Manufacturer

General Motors

Type

Gasoline

Cooling system

Water cooled

No. of cylinders – arrangement

6 – 90° V

No. of strokes

4

Type of combustion chamber

Semi -spherical

Valve arrangement

Overhead

Type of cylinder liners

Integral

Engine (gasoline and LP-gas)

Cylinder bore × stroke

Displacement

mm (in.)

101.6 × 88.39 (4.00 × 3.48)

cc (cu in.)

4293 (262)

Compression ratio Rated output

9.2 : 1 kW/rpm

69.5/2450

Maximum torque N·m (kgf·m) [lbf·ft]/rpm

305 (31.0) [224]/1200

Low idle engine speed

rpm

750

High idle engine speed

rpm

2450

Dimensions (L × W × H) mm (in.) Weight

710 × 620 × 740 (28.0 × 24.4 × 29.1)

kg (lb)

260 (573)

Installation position

Rear

Ignition

Spark

Firing order

1–6–5–4–3–2

Initial ignition timing BTDC deg

0° Gasoline/ 8° L.P.G.

Fuel tank capacity liter (U.S. gal)

115 (30)

1-7

GP50K


GENERAL INFORMATION

Truck Model GP40K

GP40KL

GP45K

Item

Ignition system

Ignition coil

Distributor

Type

Mold

Manufacturer

AC Delco

Type

Pointless

Manufacturer

AC Delco

Type of spark advance control

Internal solid state circuit

Model

#41-932

Manufacturer

AC Delco

Size

mm (in.)

14 (0.55)

Gap

mm (in.)

1.24 (0.0488)

Spark plug

Fuel system

Type

1FZ

Carburetor Manufacturer

AISAN Kogyo Co.

Type

Electromagnetic

Fuel pump

Air cleaner

Manufacturer

Jidosha Kiki

Type Ă— Number

Cyclone with paper element Ă— 1

Manufacturer

Nippon Rokaki

Engine lubrication system

Type

Pressure feed

Oil pump

Gear pump

Oil filter

Paper element

Oil cooler

Oil to water type

Refill capacities

Oil pan liter (U.S. gal)

4.2 (1.1)

Oil filter & cooler liter (U.S. gal)

0.8 (0.2)

Total liter (U.S. gal)

5.0 (1.3)

1-8

GP50K


GENERAL INFORMATION

Truck Model GP40K

GP40KL

GP45K

Item

Battery

Cooling system

Type

Forced circulation

Radiator Refill capacity

Corrugated fin with pressure type liter (U.S. gal)

17.2 (4.5)

Water pump

Centrifugal type driven by V-belt

Thermostat

Wax type

Type × number

48D26L

Voltage Capacity

V

12

AH (5 Hr)

50

Starter

Alternator

Type

3-phase AC

Manufacturer Rated output

MANDO V–A

12 – 50

Regulator

Built-in IC type

Type

Electromagnetic

Manufacturer Voltage – output

Delco Remy V – kW

12 – 0.75

1-9

GP50K


GENERAL INFORMATION

Truck Model DP40K

DP40KL

DP45K

Item Engine model

S6S

Manufacturer

Mitsubishi Heavy Industries, Ltd.

Type

Water-cooled, 4-stroke cycle

No. of cylinders – arrangement

6 – in-line

Type of combustion chambers

Swirl

Valve arrangement

Overhead

Type of cylinder liners

Dry

Bore × stroke

mm (in.)

94 × 120 (3.70 × 4.72)

Displacement

cc (cu in.)

4996 (305)

Compression ratio

Engine (diesel)

Rated output

22 : 1 kW/rpm

62.5/2450

Maximum torque N·m (kgf·m) [lbf·ft]/rpm

250 (25.5) [184]/1600

Dimensions (L × W × H) mm (in.)

907.5 × 639 × 801 (35.7 × 25.2 × 31.5)

Weight (service)

kg (lb)

350 (771)

Installation position Intake valves

Exhaust valves

Valve clearance (at cold)

Open

Rear BTDC deg

30°

Close ABDC deg

50°

Open

BBDC deg

74°

Close ATDC deg

30°

Intake valves mm (in.) 0.25 (0.0098) Exhaust valves mm (in.)

Ignition

Compression

Firing order

1–5–3–6–2–4

Ignition or injection timing BTDC deg

19°

1-10

DP50K


GENERAL INFORMATION

Truck Model DP40K

DP40KL

DP45K

Engine (diesel)

Item Fuel tank capacity

115 (30)

liter (U.S.gal) No-load minimum speed

rpm

650

No-load maximum speed

rpm

2450

Type

Bosch

Manufacturer

Fuel system

Fuel injection pump

Fuel injection nozzles

Glow plugs

Nippon Denso

Plunger diam. mm (in.)

6.5 (0.256)

Cam lift (one side) mm (in.)

6 (0.24)

Type

Throttle

Spray holes diam. mm (in.)

1.0 (0.04)

Injection pressure kPa (kg/cm2) [psi]

1372 (140) [1992]

Type

Sheathed

Voltage – current V– A

22 – 4.4

Type

Plunger

Fuel pump Manufacturer

Nippon Denso

Type × number

Cyclone with paper element × 1

Air cleaner

Lubrication system

Manufacturer

Nippon Rokaki

Type

Pressure feed

Oil pump

Trochoid type

Oil filter

Paper element type

Oil pan Refill capacities Oil filter liter (U.S. gal) Total

11 (2.9) 1 (0.3) 12 (3.2)

1-11

DP50K


GENERAL INFORMATION

Truck Model DP40K

DP40KL

DP45K

DP50K

Item

Cooling system

Type

Forced circulation

Radiator

Corrugated fin with pressure cap

Refill capacity

14.7 (3.9)

liter (U.S. gal) Water pump

Centrifugal type driven by V-belt

Thermostat

Wax type

Alternator and regulator

Battery

Type × number

48D26R × 2

Voltage

V

24

Capacity

Ah

50

Alternator type

3-phase AC Transmission cooling

Capacity

Water cooling

V–A

24 – 35

Starter

Voltage/current regulator IC type

Built-

Type

Voltage – output

Engine stop device

Stop solenoid

Mitsubishi Electric Corporation V – kW

24 – 5

Manufacturer Setting

Shin Dengen Kogyo sec

5 to 7

Operating voltage V Rated current (at 24 V)

16 to 30

11.3

V

Mitsubishi Electric Corparation

Manufacturer Detector (magnetic

Oil cooling

Electromagnetic

Manufacturer

Control timer

Manufacturer Mitsubishi Electric Corporation

Output

mA

180 minimum

1-12


GENERAL INFORMATION

Truck Model Item

GP40K DP40K

GP40KL DP40KL

GP45K DP45K

Type

Dry, single disc (OP: wet type)

Clutch Facing (OD × ID), (DP40K thru mm (in.) DP45K)

325 × 210 (12.8 × 8.3) [wet: 325 × 225 (12.8 × 8.9)]

Material

DR-8 (wet: cork)

Type Torque converter

3-element, 1-stage, 2-phase

Manufacturer’s model

Okamura M15

Stall torque ratio

3.2

Control and shift Powershift transmission

GP50K DP50K

Hydraulic and column shift

Forward

4.044

F1: 5.735 F2: 3.239

Reverse

4.057

R1: 5.735 R2: 3.239

Power train

Ratios

Manual transmission (DP40K thru DP45K)

Type

Synchro-mesh

Shift

Floor-shift

Forward ratio

Reverse ratio

1st

8.462

2nd

4.145

1st

8.489

2nd

4.159

Type of gear

Spiral bevel

Reduction gear

Differential

Gear ratio

4.857

Housing

Banjo

Type of gear – number

Straight bevel – 2

Type of pinion – number

Straight bevel – 4

1-13


GENERAL INFORMATION

Truck Model Item

GP40K DP40K

GP40KL DP40KL

Type

GP45K DP45K

Recirculating ball-and-nut

Gear ratio

20.0

Steering system

Steering wheel diameter mm (in.)

380 (15)

Type

Power steering

Semi-integral

Power cylinder ID × rod diam. mm (in.)

55 × 25 (2.17 × 0.98)

Effective stroke mm (in.)

275 (10.8)

Relief pressure kPa (kgf/cm2) [psi]

8336

Traveling system

Flow rate liter (U.S. gal)/min

+ 490 0

(85

) [1209

+ 71 0

Full-floating tubular type

Rear axle

Elliott type

Suspension Front system Rear

Fixed type

Toe-in

Center-pivot type mm (in.)

0

Camber

1.0°

Caster

0° 5.0°

Type

Self-adjusting, duo-servo

Drum diameter mm (in.) Wheel brakes

Parking brake

]

17.5 ± 0.5 (4.6 ± 0.13)

Kingpin inclination

Brake system

+5 0

Front axle

Wheel alignment

GP50K DP50K

317.5 (12.50)

Lining (length × width × thickness − number) mm (in.)

351 × 60 × 6 − 2 (13.8 × 2.4 × 0.2 − 2)

332 × 63 × 10 − 2 (13.1 × 2.5 × 0.4 − 2)

Master cylinder ID mm (in.)

22.22 (0.8748)

25.4 (1.000)

Wheel cylinder ID mm (in.)

28.58 (1.1252)

31.75 (1.2500)

Type

Mechanical, mounted on wheels

Brake booster

Mastervac (vacuum suspended)

Body

Assembled-frame type

1-14


GENERAL INFORMATION

Truck Model Item

GP40K DP40K

GP40KL DP40KL

Type

Shimazu

Hydraulic Manufacturer’s type pump Rated discharge liter (U.S. gal)/rpm

Hydraulic system

SGP2B50L979 110 (29.0)/2450

Drive line

Universal joint

Type

KVS-120VPF-2

Manufacturer

Kayaba

Relief pressure MPa (kgf/cm2) [psi] Flow regulator valve

Lift cylinders

Tilt cylinders

GP50K DP50K

Gear

Manufacturer

Control valve

GP45K DP45K

19.1 (195) [2773]

Type

Variable (Adjustable)

Regulated flow rate liter (U.S. gal)/min ID

mm (in.)

Stroke

mm (in.)

ID

mm (in.)

Stroke

mm (in.)

100 (26.4) 65 (2.56

115 (30.4)

+ 0.1 0 + 0.004 0

70 (2.76

)

+ 0.1 0 + 0.004 0

)

1500 (59.06) 80 + 00.1 + 0.004 (3.15 0 )

90 + 00.1 + 0.004 (3.54 0 ) 185 (7.28) L: 56.5 (14.9) N: 58.7 (15.5) H: 64.4 (17.0)

Hydraulic tank capacity liter (U.S. gal)

1-15


COOLING SYSTEM

Structure

1 6 5 8 5 4

10

1

2 3 2

3 207009

208411 8

Transmission cooling

Water cooling

9 Oil cooling

7

6 9 208413

1 2 3 4 5

Engine Universal joint Gear pump Fan belt Cooling fan

6 7 8 9 10

2-1

Upper hose Lower hose Radiator Oil cooler hoses Tension pulley


COOLING SYSTEM

Removal and Installation Fan Belt Removal

3 1 2 (Only loosen.)

208414

Sequence 1 2 3

Universal joint Tension pulley assembly, Bolt Fan belt

Start by:

Remove the radiator cover.

Suggestion for removal

Tension pulley assembly

(1) Using a ratcheting wrench inserted in the gap between the weight and frame, loosen the tension pulley lock bolt by three or four turns. If the bolt is loosened insufficiently, the tension pulley will not be moved.

A

A

NOTE Do not loosen the lock bolt to such an extent that the tension pulley would be removed. (2) Move the tension pulley fully toward the fan, then remove the belt. 2-2

Tension pulley lock bolt

Section A–A

208415


COOLING SYSTEM

Installation Perform installation by following the removal sequence in reverse. Also follow the instructions given below. (1) Before installing the belt, turn the fan to check for smooth rotation. Replace the bearing if it generates abnormal sound. (2) After installing the belt, push it at a point midway between the driven and drive pulleys to make sure that the tension pulley moves, then tighten the pulley lock bolt firmly.

Fan Assembly Removal

1 3 2

208416

Sequence 1 2 3

Fan cover Fan assembly Tension pulley assembly

Start by:

Remove the radiator cover.

Suggestion for removal Remove the fan support bolts, detach the belt from the driven pulley, and then remove the fan assembly. Place the fan assembly with the fan support facing down and turn the fan to check for smooth rotation. Replace the bearing if it generates abnormal sound.

2-3


COOLING SYSTEM

Installation Perform installation by following the removal sequence in reverse. Also follow the instruction given below. (1) With the tension pulley lock bolt loosened, attach the belt to the driven pulley (fan assembly pulley), then screw in the bolt at the bottom of the fan support; do not tighten the bolt yet. Holding the fan support by its top, move the support until it reaches the boss (frame), then tighten all the fan support bolts. (2) Adjust the tension of the fan belt.

2-4


COOLING SYSTEM

Inspection and Adjustment Fan belt condition (1) Check the belt for contamination with oil, grease and/or dust. If the contamination is slight, remove it clean with rag or wiping paper. Do not use gasoline, oil or any other solvent to clean the belt. (2) During engine overhaul or belt tension adjustment, closely check the belt for condition. Replace the belt with a new one if it has any sort of damage.

Fan belt tension Apply a force of 98 N (10 kgf) [22 lbf] perpendicularly to the belt at a point midway between the fan pulley and tension pulley. If necessary, adjust the tension by moving the tension pulley assembly such that the belt deflects 16 mm (0.63 in) when pressed with the above force. After adjustment, tighten the tension pulley assembly lock bolt firmly.

Connecting Radiator Hoses When connecting the hoses to the radiator, fit their ends fully on the fittings and secure them with clamps. Tighten the clamp bolts to the torques indicated below. Make sure that each hose is correctly retained and prevented from disconnection by the flare of the fitting.

Clamp bolt tightening torques

Upper and lower hoses

Cooler hose

3.92 to 5.88 N·m (0.4 to 0.59 kgf·cm) [2.9 to 4.3 lbf·ft] 2.94 to 4.9 N (0.3 to 0.5 kgf) [2.2 to 3.6 lbf]

2-5


COOLING SYSTEM

Coolant Fill the radiator with coolant containing antifreeze. Start and operate the engine to let it warm up while checking for abnormal noise. Make sure that the quantity of coolant is as specified by checking the level in the reserve tank.

Quantity of coolant

Unit: liter (U.S. gal) Truck Model

GP40K, GP40KL, GP45K, GP50K Powershift transmission models

DP40K, DP40KL, DP45K, DP50K Powershift transmission models

Engine

11 (2.9)

7.1 (1.9)

Radiator

4.3 (1.1)

4.7 (1.2)

Reserve tank (FULL level)

0.65 (0.17)

0.65 (0.17)

Total quantity of coolant (including coolant in hoses)

17.2 (4.5)

14.7 (3.9)

Oil cooler

0.62 (0.16)

0.31 (0.08)

Item

Radiator Cap Opening pressure

Vacuum valve

90 ± 15 kPa (0.92 ± 0.15 kgf/cm2) [13.1 ± 2.2 psi] 0 to 5 kPa (0 to 0.05 kgf/cm2) [0 to 0.73 psi]

2-6


ELECTRICAL SYSTEM

Structure and Functions Console Box 1 2 3 4 5 6 7 8 9

Engine coolant temperature gauge Travel speed select switch Fuel gauge (for diesel-engine models) Service hourmeter OK monitor Starter switch Lighting switch Fuse box Auto-light switch (for FC models)

103249

3-1


ELECTRICAL SYSTEM

OK Monitor

103239

Function

No.

Indicator light

OFF

ON or flickering

Remarks

1

Powershift transmission oil temp. indicator light

Normal

Overheating

2

Air cleaner element indicator light

Normal

Clogged

3

Brake fluid level indicator light

Normal

Low

4

Engine oil pressure indicator light

Normal

Low

5

Alternator not charging indicator light

Normal

Abnormal

6

Heater plug indicator

Normal

7

LP-Gas residual pressure alarm lamp

Normal

Drain water

Option

8

System indicator light

Normal

Abnormal

FC models

9

Engine coolant level indicator light

Normal

Low

Option

Option

Diesel-engine models

How to check indicator light bulbs

The bulbs are normal if all the indicator lights come ON when the starter switch key is turned to the position. (The indicator lights will go OFF when the engine starts.)

Truck Model

Indicator light No.

MC diesel-engine model

1, 2, 3, 4, 5, 6

MC LPG-engine model

1, 2, 3, 4, 5

FC diesel-engine model

1, 2, 3, 4, 5, 6, 8

FC LPG-engine model

1, 3, 4, 5, 8

3-2

(ON)


ELECTRICAL SYSTEM

Electrical Components Mounted on Body

208773

1 2 3 4 5 6

Main harness Fusible link (R.H.) Fusible link (L.H.) Fuse Fuse Power relay (FC model)

7 8 A: B:

3-3

System harness Harness (tilt earth) To forward/reverse lever To turn signal switch


ELECTRICAL SYSTEM

Disassembly and Reassembly Console Box

208774

Disassembly

Reassembly

1. Disconnect the electrical wires at connectors 1.

To reassemble the console box, follow the reverse of disassembly procedure.

(Disconnect the choke cable on the engine side.) 2. Remove four screws 2 securing the cover. 3. Remove six screws 3 and separate the front and rear panels. 4. Remove four screws 4 securing the instrument panel.

NOTE To replace the instrument panel bulbs, remove screws 3 and 4.

3-4


ELECTRICAL SYSTEM

Console Box

208789

Disassembly

Reassembly

1. Remove two screws 1 securing the cover. (Use a flat-tip screwdriver)

To reassemble the console box, follow the reverse of disassembly sequence.

2. Remove six screws 2 and separate the front and rear panels. 3. Remove four screws 3 securing the instrument panel.

NOTE To replace the instrument panel bulbs, remove screws 2 and 3.

3-5


ELECTRICAL SYSTEM

Components in Console Box

9 6 5

4 3 2 7

1

8

208556

1 2 3 4 5

Power relay Power relay (diesel-engine models) Turn signal relay Glow plug relay (diesel-engine models) Glow plug timer (diesel-engine models)

6 7 8 9

3-6

Lighting switch Starter switch Fuses Travel speed select switch


ELECTRICAL SYSTEM

Combination Meter Disassembly

1

2 3 4

5

6

7 8 9 206480

Sequence 1 2 3 4 5

Instrument panel Dial Engine coolant temperature gauge Service hourmeter Fuel gauge (diesel-engine models)

6 7 8 9

Meter case Printed circuit plate Bulb Socket

CAUTION Be careful not to damage the printed circuit plate when disassembling the combination meter.

Reassembly

Bulb replacement

To reassemble the combination meter, follow the reverse of disassembly sequence.

For bulb replacement, remove the socket from the printed circuit plate by turning it to the left. For configuration of the indicator lights, refer to the preceding section “OK Monitor�. 3-7


ELECTRICAL SYSTEM

Major Electrical Components Starter Switch (with Anti-Restart Lock) engine models use the same starter switch. In the diesel-engine models, (ON) position of the switch is for energizing the glow plugs.

This switch has a built-in anti-restart lock, so the key cannot be turned from (ON) to (START) position while the engine is running. The LPG- and diesel(OFF) (ON)

(START)

G1

M

B2

G2 B1

S 203561A

Connection chart LPG-engine models (12 V)

Terminal Component Key position

B1, B2

G1

G2

Fuse box, battery, alternator

(OFF)



(ON)



(START)



M

S

Fuse box

 





G2

M

S

Fuse box

Glow plug timer

Diesel-engine models (24 V)

Terminal Component Key position

B1, B2

G1

Fuse box, glow plug relay, battery, alternator

(OFF)



(ON)



(START)



 





NOTE The starter switches for both LPG and diesel engines are same in design. With a LPG engine, therefore, turning the key to a position on the left of the OFF position is possible but does not cause any effect as there is no electric circuit connected there. 3-8


ELECTRICAL SYSTEM

Lighting Switch OFF 1st 2nd 8 8 (0.3) (0.3)

Knob position Stroke [Unit: mm (in.)]

206481

Connection chart

B

Terminal Component

Battery (fuse)

Knob position

T Tail lamps, instrument panel lamp

H

P

Head lamps

Clearance lamps

(OFF) 1st position





2nd position





 



If the insulation resistance between any two terminals is not up to the specification indicated below when the knob is in the OFF position, the lighting switch must be replaced with a new one. Insulation resistance

1 M ohm or higher (as measured by a 500 V megger)

Turn Signal Switch Connection chart

Terminal

L N

RF LF

R

Lever Component position R (Right)

F

RF

Turn signal Turn signal relay (L) (RH)

LF Turn signal (LH)











Green

Yellow

Black

N (Straight) F

L (Left) 203573

Cord color

If the insulation resistance between any two terminals is not up to the specification indicated below when the lever is in the N position, the turn signal switch must be replaced with a new one. Insulation resistance

1 M ohm or higher (as measured by a 500 V megger) 3-9


ELECTRICAL SYSTEM

Fuel Tank Unit

212.4 mm (8.36 in.)

141.4 mm (5.57 in.)

F To fuel gauge 3/4

To ground

Indication accuracy

1/2

Terminal Item

E

1/4

1/2

3/4

F

80

49.5

32

19

10

+ 12 +2

±3

+ 1.0 − 0.5

1/4

Standard resistance (ohm) Tolerance

E

(ohm)

203574

3-10


ELECTRICAL SYSTEM

Fuse Box A B C D E F G H J

103240

MC Model

FC Model

Gasoline-engine models Code

Capacity

Circuit

A

10 A

B

15 A

C

15 A

D

15 A

E

15 A

Directon lever, delay timer Instrument panel, stop lamp switch, T/M controller Spare power source Head, working (opt) lamps Spare fuse

F

10 A

Spare fuse

Diesel-engine models Capacity 10 A

Gasoline-engine models Code

Circuit

Capacity

Circuit

Directon lever, delay timer Instrument panel, turn signal lamps

A

10 A

B

15 A

C

15 A

D

15 A

10 A

Spare power source Head, working (opt) lamps Horn

E

15 A

Directon lever, delay timer Instrument panel, stop lamp switch, T/M controller Spare power source Auto light switch, working (opt) lamps Head lamps

10 A

Spare fuse F

10 A

G

10 A

10 A 15 A

G

10 A

Horn

10 A

Stop lamps

H

15 A

Spare fuse

10 A

Backup lamps

J

10 A

Spare fuse

15 A

Spare fuse

Diesel-engine models Capacity 10 A

Circuit

15 A

Directon lever, delay timer Instrument panel, stop lamp switch, T/M controller Spare power source Auto light switch, working (opt) lamps Head lamps

FC controller

10 A

FC controller

10 A

Horn

10 A

Horn

H

15 A

Spare fuse

15 A

Backup lamps

J

10 A

Emergency switch

10 A

Emergency switch

15 A

15 A 15 A

Spare Terminals The spare terminal cord extends from the fuse box in the console box. (Another spare terminal is located on the chassis-side main harness.)

Cord color

Lg (light green)

Removing the console box rear panel will expose this spare terminal which is fastened to the harness protector with vinyl tape.

Spare terminal 207209

3-11


ELECTRICAL SYSTEM

Lamp Bulb Specifications Item Type of lamp Head lamps

No. of bulbs

Color of lens

Watts 12 volt 24 volt

2

Colorless

45

60

Turn signals

2

Amber

27

25

Clearance lamps

2

Amber

10

12

Turn signals

2

Amber

27

25

Tail/stop lamps

2

Red

8/23

10/25

Backup lamps

2

Colorless

10

12

2

Colorless

45

60

3 (14 volt)

3

Shape

Remarks

Standard: Installed on overhead guard

Combination lamps (front)

Combination lamps (rear)

Working lamps (front and rear)

OK monitor indicator lamps and instrument panel lamp

8 (Diesel) or Colorless 7 (LPG)

Option

200016A

3-12


ELECTRICAL SYSTEM

Battery Maintenance 1. State of charge and electrolyte specific gravity (S.G.) adjustment

Specific gravity reading at 20°C (68°F)

State of charge

Adjustment

1.280 to 1.265

Fully charged

If difference in S.G. between any two cells is 0.040 or more, effect a high current discharge to minimize the difference and then recharge battery. Adjust S.G. during recharging.

1.260 to 1.225

One-half charged

Recharge battery and adjust electrolyte S.G. Make sure there is neither faulty components, loosely connected cord nor corroded connection.

1.220 or below

Discharged

Recharge battery. If difference in S.G. is large, adjust it during recharging.

If difference in S.G. is more than 0.040

A cell with a low S.G. is in shorted condition. Recharge until voltage and S.G. stabilize and have remained constant for more than 2 hours.

During recharging, adjust S.G. to 1.280 to 1.265. If difference in S.G. is more than 0.040 and a low S.G. is found in certain cells only, replace battery. After leaving battery for 12 to 96 hours, conduct a high current discharge test.

(4) When connecting the cables to the battery, begin with the cable for the positive (+) terminal. When disconnecting them from the battery, begin with the cable for the negative (−) terminal.

2. Specific gravity reading and state of charge

To check the battery for state of charge, take hydrometer readings on its electrolyte. The battery may be fully charged if the S.G. reading is 1.280 to 1.265 at 20°C (68°F). The state of charge can be told from the way the electrolyte level goes down to expose the cell plates. If addition of distilled water is necessary every month or so, the battery is overcharged. If addition is not required for more than 3 months, it is likely that the battery is inadequately charged.

CAUTION Be sure to turn OFF the starter switch and lighting switch before disconnecting or connecting the battery cables to prevent the IC regulator from suffering damage.

3. Charging precautions

(1) In slow charging, the charging current should be about 1/10 the capacity of the battery to be charged. (2) In quick charging, the battery capacity in ampere should not be exceeded. (3) During charging, adjust the charging current to prevent the electrolyte temperature from rising beyond 45°C (113°F).

3-13


ELECTRICAL SYSTEM Precautions for servicing charging system (with alternator)

The alternator is equipped with a built-in IC (integrated circuit) voltage regulator. When servicing the charging system, pay attention to the following precautions: (1) Do not reverse the polarity of the battery. (2) Do not disconnect the battery terminal while the engine is running.

Terminal L

(3) Do not ground the terminal L. Terminal R

(4) Do not short the terminals L and R. (5) Do not direct a blast of steam cleaner to the alternator. Remember, a blast of steam will damage the IC regulator.

3-14

Terminal B

202772


ELECTRICAL SYSTEM

FC (Finger-Tip-Control System) Nomenclature 5

1

6

2

3 7 8 9 4

103237

1 2 3 4 5

Light sensor Auto-light switch Flow regulator valve Solenoid control valve Seat switch

6 7 8 9

3-15

Lowering speed selector switch Safety switch Joystick levers (finger-tip-control system) Controller


ELECTRICAL SYSTEM

Maintenance Precautions The FC model contains a microcomputer. Following are the precautions to be observed in performing any maintenance on the FC model. (1) When removing the controller cover, make proper provisions to keep out rain, washing water splashes and the like. (2) After using the controller setting switch, check to make sure the control system is in keeping with the truck specifications.

NOTE

208775

Improper setting of the system will result in inability to lower the forks in an inching manner. (See “How to Set Controller�.)

(3) Before performing repairs which require welding, be sure to disconnect the cable from the battery positive (+) terminal and the controller from the system at its connectors. (4) When handling the controller by hand, never touch its electrical terminals, or your body charge will rupture some of the electronic elements in the internal controller circuits.

3-16

208776


ELECTRICAL SYSTEM

Description 1. Finger-tip-control system

This system, unlike the conventional mechanical control, is electronically actuated to help reduce the effort required of the operator in moving the control levers for lift, tilt and attachment functions.

101466B

[Features]

(1) The lowering speed selector switch insures smooth fork and mast movement no matter how abruptly the operator may move the control levers. This switch is ideal for handling of fragile loads.

ON: 350 mm/s (69 fpm) OFF: 500 mm/s (98 fpm) 204992B

(2) This system provides the following safety functions: (a) The lift, tilt and attachment functions are not performed even if the control levers are moved when the engine is not running.

(d) The system indicator light in the OK monitor alerts the operator to problems occurring in the electrical system and, at the same time, stops function. (If any problem occurs in the lift system, for example, the system becomes inoperative.)

(b) The lift, tilt and attachment functions are not performed even if the control levers are moved when the safety switch is in ON (pushed) position. (c) The lift, tilt and attachment functions are not performed even if the control levers are moved when the seat switch is not ON (the operator is not seated).

3-17


ELECTRICAL SYSTEM 2. Auto-light system

The head lamps are under the control of switch and sensor. With the auto-light switch ON, the head lamps turns ON automatically as the truck is driven into a dark area. The head lamps can be turned ON or OFF manually.

101489

Operating Principles 1. Finger-tip-control system

(1) The system is activated by turning ON the safety switch when the engine is running and the seat switch is ON (when the operator is seated). (2) As the control levers (joysticks) are moved to operate the equipment (mast and forks), the amount of lever movement will be translated into an electrical signal: this signal goes into the controller, in which it is converted to and output signal. At this point the controller issues and ON signal to the unload solenoid, thereby turning ON this solenoid to introduce hydraulic pressure into the control valve. The system is now ready to actuate the equipment. The output signal applies to the proportioning solenoid selected by the direction of the joystick movement. Inside the control valve of that solenoid, its spool is forced to slide, altering the internal oil passage to direct the oil to the corresponding cylinders. The spool keeps on sliding until it comes to the position at which the pressure of its pilot chamber becomes equal to the force of its centering spring. In the meantime, the cylinder extends or retracts against its load. As the joystick is moved back to its neutral position, the signal to the proportioning solenoid dies to lower the pilot chamber pressure and allow the centering spring to push the spool to its neutral position, whereby the line to the cylinder becomes shut off: the pressure in the line is now trapped, holding the cylinder there. At the same time, the ON signal to the unload solenoid goes OFF, so that the part of the system actuating the equipment goes into no-load state.

3-18


ELECTRICAL SYSTEM

(3) Power supply to the controller is initiated from the starter switch through a 10-Amp fuse and safety switch. Pressing this switch into OFF position shuts down the controller without shutting down the engine. (4) With the starter switch and safety switch turned ON, the unloading solenoid and proportioning solenoid are under control of the joysticks. With the engine shut down (and hence the hydraulic pump standing still), the spools in the control valves are inoperative because no pressure develops in their pilot chambers. Consequently, the equipment remains inoperative even when the starter switch and safety switch are turned ON.

3-19


Lift cylinder

Fuse 10 A

3-20 Hydraulic pump

Unload solenoid

Starter switch (ON)

System indicator light

Console box

Finger-tip-control system schematic

Solenoid control valve

Proportioning solenoid

Seat switch (ON)

Spool

Safety switch (ON)

Pilot pressure passage

Centering spring

Pilot pressure passage

Proportioning solenoid

Power supply

Power supply

Lowering speed selector switch

Flow control signal

Detail of control valve

Control lever (joystick)

Control (joystick) box

Battery

Lever stroke signal

ON-OFF signal

Power supply

Setting window

Controller

ON-OFF signal

ON-OFF signal

Safety switch (OFF)

208777

ELECTRICAL SYSTEM


ELECTRICAL SYSTEM

(5) In addition to the functions explained above, the controller monitors the supply voltage and the electrical connections for the control levers (joysticks), solenoids and other input/output devices, and alerts the operator to a problem, if occurs, by flickering the system indicator light and turning ON this light and also LED (as shown in the chart below). Such a problem is usually a fault in the harness or connector and must be located by inspecting. The hydraulic components such as pump control valve, etc. are not monitored.

LED flickers

LED flickers

LED flickers

LED flickers LED flickers

LED flickering pattern

1.2 sec.

1.2

1.2

Problem detected

208778

Effect

1.2

(Normal)

0.3

2.1

System indicator light

0.3

2.1

OFF

Open- or short-circuit in control lever (with starter switch in ON position)

No power supply to particular system

ON

Supply voltage too high (over No power supply 32 volts or too low under 9 volts) to all systems

0.6 0.6

ON

1.2

0.6 0.6 0.6 0.6

1.2

Open- or short-circuit in solenoid

No power supply to particular system

Control lever neutral position displaced

No power supply to particular system Flickers

Open- or short-circuit in control lever (with starter switch in ON position) 1.2

0.3 0.6

LED remains ON

0.3 0.6

0.6

0.3 0.9

Seat switch OFF, of open-circuit in it

No power supply to all systems

Flickers

Problem in controller

NOTE: Any problem does not cause the engine to shut down. 204995A

3-21


ELECTRICAL SYSTEM 2. Auto-light system

Example: The auto-light system functions regardless of ON-OFF of the seat switch. The fingertip-control system functions even if the light sensor is faulty.

(1) The auto-light system turns ON the head lamps automatically when the truck is driven into a dark area, with the starter switch in (ON) position, the safety switch ON and the auto-light switch ON. The controller is common to this system and the finger-tip-control system but the circuit of the system is independent so the components of these systems do not affect each other in operation.

Light sensor 208779

208780

Auto-light switch

Power relay 102454

208781

Major Components of Auto-light System

NOTE The controller has no auto-light system diagnosing function.

3-22


ELECTRICAL SYSTEM

(2) The light sensor is basically a resistance device, whose resistance is compared with that in the variable resistor (the auto-light sensitivity adjusting knob) inside the controller. The sensor resistance increases as brightness decreases. When, in operation, the sensor resistance becomes greater than the resistance in the variable resistor, the comparing circuit energizes the power relay to close its contacts to turn ON the head lamps. With auto-light switch ON, starter switch (ON) and safety switch ON Control (joystick) box Head lamp

Instrument panel lamp Power supply

Tail lamp Console box Clearance lamp

B

PHT

Lighting switch

Safety switch (ON)

Starter switch (ON) Controller (ON)

10 A 20 A

Auto-light switch (ON)

Battery

Dark Light sensor

Setting window

Power relay (ON)

Auto-light sensitivity adjusting knob 208782

Operation–1

3-23


ELECTRICAL SYSTEM

(3) With the auto-light switch turned OFF, the lighting switch can be used to turn ON a light selected by the position of this switch. Even under this condition, the power relay goes ON or OFF in response to changes in ambient brightness but this does not affect the light turned ON by the lighting switch. With the auto-light switch OFF, the starter switch (ON) and the safety switch ON. With auto-light switch OFF, starter switch (ON) and safety switch ON Control (joystick) box Head lamp Instrument panel lamp Power supply

Tail lamp Clearance lamp

Console box B

PHT

Lighting switch

Safety switch (ON)

Starter switch (ON) Controller (ON)

10 A 20 A

Auto-light switch (OFF)

Battery Setting window

Dark Light sensor

Power relay (ON)

208783

Operation–2

3-24


ELECTRICAL SYSTEM

(4) Turning OFF the safety switch with the auto-light switch ON causes the power relay to remain OFF. Under this condition, all lamps will not come ON. If the auto-light switch is OFF, the lighting switch is effective and can turn ON each selected light, regardless of the safety switch and starter switch. With auto-light switch ON and safety switch ON Control (joystick) box Head lamp Power supply

Tail lamp Clearance lamp

Console box B

P HT

Safety switch (OFF)

Lighting switch Starter switch

Controller (OFF)

10 A 20 A

Auto-light switch (ON)

Battery Setting window

Dark Light sensor

Power relay

208784

Operation–3 Operation logic:

Auto-light switch ON

Auto-light switch OFF Lighting switch

OFF

1st 2nd position position

Dark OFF

Clearance, tail lamps Head lamps

3-25

1st 2nd position position

Bright OFF

1st 2nd position position


ELECTRICAL SYSTEM

How to Set Controller Set the controller on any of the following occasions: Occasion

Setting

After mast has been changed, or an optional equipment added

Resetting of setting switches

When auto-light system is adjusted

Adjustment of brightness at which light sensor operates

After control valve lift section solenoid has been replaced (or control valve replaced)

Adjustment of maximum lowering speed (when required)

After controller assembly has been replaced

• Resetting of setting switches • Adjustment of maximum lowering speed (when required) • Adjustment of brightness at which light sensor operates (when required)

208785

3-26


ELECTRICAL SYSTEM 1. Setting switches

The controller has a total of 16 setting switches.

NOTE Use a screwdriver to move each switch. The switch is made of resin; be careful not to damage the switch head in setting. 205001

(1) Switch setting pattern (Black dot indicates switch head.)

Setting window

Transmission speed Switch SW 2–2 Spear Switch SW 2–3

Normal OFF

Check ON

1200 bps OFF Normal OFF

Truck model Switch SW 3–1 SW 3–2

9600 bps ON

With OFF

Without ON

Oil pressure sensor Switch SW 2–5

Without OFF

(With) ON

OFF

Seat switch Switch SW 2–4

Spear Switch SW 2–6

Normal OFF

40K OFF OFF

40KL OFF OFF

45K OFF OFF

50K OFF OFF

– ON

– ON

WDT operation Normal mode WDT disabled Switch SW 2–7 OFF ON

1 2 3 4 5 6 7 8

OFF

Mode Switch SW 2–1

1 2 3 4 5 6 7 8

SW2

SW3

OFF

ON

No. of spools Switch SW 3–3 SW 3–4

3V ON OFF

4V OFF ON

– ON ON

Mast model Standard Simplex Duplex SW 3–5 Switch OFF OFF OFF SW 3–6 OFF OFF OFF

Spear Switch SW 3–7 Spear Switch SW 3–8

Program mode User program Boot mode Switch SW 2–8 OFF ON

2V OFF OFF

Normal OFF Normal OFF

Triplex OFF OFF

– ON – ON

208786

(2) Example of setting Truck:

GP40K

40 K

No. of spools: 3V Mast:

4V40A (simplex)

Option:

Speedometer with indicator light

3V

Seat switch

Standard

SW2

SW3 208787

3-27


ELECTRICAL SYSTEM 2. Failures resulting from incorrect setting

(1) Incorrect setting for truck size (4.0 ton, 4.5 ton and 5.0 ton models) Incorrect setting will result in abnormal lowering speed and inching feel. If a setting for a 4.0 ton model is made on a 4.0 ton mode, for example, the lowering speed will be abnormally low. If a setting for a 4.5 ton model is made on a 5.0 ton model, the lowering speed will be abnormally high. (2) Incorrect setting for number of control valve spools (a) If the setting is made for the number of spools greater than is actual, the system indicator light will flicker, and the equipment will not be actuated. (Such a setting is taken as open- or short circuit in the control valve solenoid or in the joysticks.) (b) If the setting is made for the number of spools less than is actual, only the devices equal to the number of the set spools will be actuates. (3) Incorrect setting for mast A setting for a simplex mast will not affect the lowering speed. (4) Incorrect setting for controller check (Be sure to set to OFF.) If it is set to ON, the equipment will not be actuated even if the joysticks are operated.

3. Lowering speed adjusting knob

(1) This knob is for increasing or decreasing the maximum lowering speed. (2) The arrow of the knob has been set to “8”. (3) The lower the figure, the more the lowering speed is decreased. “A” thru “F” mean “10” thru “15”.

NOTE (1) Use a screwdriver to turn the knob. (2) This knob can be turned endlessly in both directions. (3) Be careful not to damage the groove of the knob when putting a screwdriver.

3-28

205004


ELECTRICAL SYSTEM 4. Auto-light sensitivity adjusting knob

(1) This knob is for adjusting the sensitivity level at which the auto-light system turns ON and OFF the head lamps. (2) The knob has been set as shown. (3) The more the knob is turned to the right, the lower will be the sensitivity at which the system turns ON and OFF the head lamps. 205005

NOTE (1) Use a screwdriver to turn the knob. (2) Be careful not to damage the groove of the knob when putting a screwdriver.

5. Working precautions

(1) When installing the controller, position it correctly. Be careful not to turn upside down. (2) When resetting or adjusting the controller on the truck, be sure to turn OFF the starter switch and lighting switch. (3) When removing the rubber cover, check to see if the sealing label was removed before. (If this label shows a sign of removal, ask the user for removal of the label.) (4) Be careful not to damage the rubber cover when it is off the controller. (5) Do not let any foreign matter fall into the controller through setting window.

3-29

205037


ELECTRICAL SYSTEM

Troubleshooting Starter System

Starter will not crank engine

Starter switch Turning off starter switch will not stop engine

Weak or dead battery

Recharge or replace.

Short or open circuit

Repair or replace.

Poor continuity in starter switch

Replace.

Starter or starter relay defective

Replace.

Forward-reverse lever not in neutral position

Move lever to neutral position.

Open or short circuit

Repair or replace.

Engine stop solenoid defective

Replace or readjust.

Control timer defective

Replace.

Open or short circuit

Repair or replace.

Gauge internally defective

Replace.

Gauge unit defective

Replace.

Gauge or gauge unit not of the type called for

Replace.

Loose terminal connection

Repair.

Circuit between gauge and gauge unit grounded

Repair.

Gauge internally defective

Replace.

Open or short circuit

Repair or replace.

Gauge internally defective

Replace.

Gauge unit defective

Replace.

Gauge or gauge unit not of the type called for

Replace.

Loose terminal connection

Retighten.

Circuit between gauge and gauge unit open or short

Repair.

Gauge internally defective

Replace.

Gauge unit defective

Replace.

Circuit between gauge and gauge unit grounded

Repair.

Gauge unit defective

Replace.

Gauge internally defective

Replace.

Gauges Will not indicate at all

Temperature gauges

Will not indicate accurately Will indicate higher than actual temperature

Will not indicate at all

Will not indicate accurately

Fuel gauge

Will indicate “full” regardless of amount of fuel left in tank

Will indicate “empty” regardless of amount of fuel left in tank

3-30


ELECTRICAL SYSTEM

Lighting System

Will not light

Lamps - general

Will light dimly

Head lamps

Will not light

Will not flicker Will not go out Turn signals

Will flicker too slow Will flicker too fast

Other lamps

Weak or dead battery

Recharge or replace.

Fuses blown out

Check and replace.

Open or short circuit

Repair or replace.

Poor grounding

Clean ground spot and re-make connection.

Bulbs burnt out

Replace.

Weak or dead battery

Check and recharge.

Burned contact points in switches

Repair or replace.

Loose terminals

Retighten.

Dirty lenses

Clean.

Waterdrops inside lenses

Dry and replace packings.

Bulbs expired in service life

Replace.

Lighting switch defective

Replace.

Bulbs burnt out

Replace.

Turn signal switch defective

Replace.

Turn signal relay defective

Replace.

Turn signal relay defective

Replace.

Bulbs burnt out

Replace.

Wrong wattage of bulbs

Replace.

Bulbs burnt out

Replace.

Turn signal relay defective

Replace.

Wrong wattage of bulbs

Replace.

Turn signal relay defective

Replace.

Backup lamp switch defective

Correct if improperly installed: replace if internally defective.

Bulbs burnt out

Replace.

Fuse blown out

Check and replace.

Open or short circuit

Repair or replace.

Horn switch defective

Replace.

Horn defective

Replace.

Horn button defective

Repair or replace.

Horn switch defective

Replace.

Horn defective

Replace.

Backup lamps will not light

Alarm Unit

Will not give blast of sound Horn Will give ugly blast of sound

3-31


ELECTRICAL SYSTEM

Battery Drive belt slipping

Readjust.

❋ Alternator Stator coil grounded or open-circuited

Repair or replace.

Rotor coil open

Replace.

Brushes poorly seating on slip rings

Replace brushes if worn. Clean holder and polish slip rings.

Diode ruptured

Replace.

❋ Regulator Tends to run down rapidly

Regulated voltage setting too low

Readjust.

❋ Battery Not enough electrolyte or wrong proportion of acid to water

Refill and check specific gravity.

Battery cell plates deteriorated (forming, possibly internal short-circuit)

Replace.

Terminal connections loose

Clean and retighten.

❋ Wiring Open or loose connection between starter switch and regulator IC terminal

Repair.

Fuse blown, or loosely set in holder

Replace and repair.

Open or loose connection between F terminals of regulator and alternator

Repair.

❋ Wiring

Tends to get overcharged

Regulator IC and F terminals shorted or miswired

Repair.

Poor grounding of regulator F terminal

Repair.

❋ Regulator Pressure coil open-circuited

Replace.

Regulated voltage too high

Readjust.

3-32


ELECTRICAL SYSTEM

FC (Finger-Tip-Control System) 1. Preparatory steps

(1) This system comes into operation when the starter switch is turned to the ON position and the safety switch is turned ON. The finger-tip-control comes into operation after the seat switch has been closed (the operator has been seated) and the engine has been started. (2) Before deciding to replace a blown fuse, check to be sure that the harness connectors in the power line are all in sound condition, free of any sign of short-circuit. (3) The use of the test-use connector (special tool) is prescribed for checking the connector-to-connector (special tool) is prescribed for checking the connectorto-connector lines for continuity and for reading the voltage across two terminals and the ohmic resistance of a line. (4) The controller ’s capabilities include that of selfdiagnosis (for the control system only) function. By this function, any trouble symptom occurring in energized state goes into memory as trouble data. (This memory capability is limited, however, to the latest single case of trouble symptom for one input/output channel: previous symptoms are not memorized, meaning that their chronological order and data are not traceable). The trouble symptom data, limited as above, can be read out through the ground support equipment (GSE). If, however, any of the following steps is taken, the stored data will be erased and lost:

205038

(e) Turning starter switch or safety switch ON and OFF twice in succession. (Turning the switch in this manner is the same thing as performing the cycle of energizing and de-energizing the controller twice in succession.)

(a) Disconnecting battery lead from the battery terminal, positive (+) or negative (–). (b) Uncoupling CN1 or CN4 connector on the console box. (c) Removing the 10-A fuse (6th fuse as counted from top) in the fuse box. (d) Uncoupling CN53 connector on the controller.

3-33


ELECTRICAL SYSTEM

(6) Before starting troubleshooting work, check to be sure that the following conditions are met on the machine side:

(5) When coupling or uncoupling a connector, make sure that the starter switch is OFF. Never try to insert or pull off the connector half forcibly or its pins will suffer damage. When coupling a connector, be sure that the inserted half snaps into its self-locking position. Conditions in the machine Starter switch OFF Safety switch OFF

Engine at standstill Starter switch ON Safety switch ON

Engine running Safety switch ON

Check item

What to check

Remedy

Hydraulic line

Hoses, pipes and connectors for damage and sign of leak.

Repair leaking or damaged parts.

Hydraulic devices

Check control valve and hydraulic cylinders for damage and oil leaks.

Repair damaged or leaking parts, if any.

Electrical connectors and wires

Check connectors for tightness, burns and breakage; check wires for insulator stripping and signs of rubbing.

Repair.

Power source voltage

Check to be sure that voltage is at least 10 V as read across battery’s terminals.

Correct alternator or battery if this voltage is too low.

System check lamp

Check to be sure the lamp goes ON and OFF properly; if not, check its bulb.

Replace lamp bulb if blown.

Auto-light unit

After making sure check light bulb is OK, see if auto-light works properly.

Refer to Case 1 and 2.

LED indicator (red) in the controller

Be sure that red LED go ON and OFF correctly.

Proper functioning of LED indicator is essential to troubleshooting.

Trouble-data reading function of controller

Connect GSE to controller and check its input and output actions.

(Proper functioning of controller is essential to troubleshooting.)

Hydraulic devices

With your hands kept off control levers, see if solenoid valves and hydraulic pump are making any abnormal sound.

Refer to the sections dealing with control valve and hydraulic

pump, respectively. Operate control lever to see if any abnormal sound, indicative of flow throttling, comes from control solenoid valve or from any other solenoid valve. Check to see if unload solenoid valve operates properly, in response to a lever being moved. Work attachments

Check each work attachment for the following: (a) Does it work properly? (b) Does it “inch” properly? (c) Does mast go down with proper speed?

3-34

(Proper function of solenoid valves is essential to troubleshooting.)

Refer to Case 3. Refer to Case 4.

Refer to Case 5.


ELECTRICAL SYSTEM 2. Connecting the GSE to the Controller

(1) Remove the rubber cap.

208788

(2) First, turn ON the starter switch. After this, select the lift menu (by referring to the GSE operation manual).

NOTE Before plugging in or unplugging the GSE cable, be sure to have the starter switch turned OFF.

3-35


ELECTRICAL SYSTEM 3. Troubleshooting Cases as Examples

(1) Explanatory notes and reminders (a) In the text and diagrams to follow, electrical connectors are abbreviated CN. An individual CN will be identified by a number suffix (used in the electrical wiring and connecting diagrams). (b) In the flowchart diagrams, the numerical notation in the box, , is a circuit number. The terminals of a connector too will be identified by circuit numbers. As to the configuration of terminals in each connector, refer to the wiring diagram. (c) The wiring diagrams show the connector’s terminal configuration on its male side: remember, the configuration on the female side is a mirror image of the male-side configuration. (d) In the trouble cases cited hereunder, “check the connector coupling” means “uncouple and then couple the connector, inserting the connector, inserting the connector half all the way to selflocking position.” (e) In the trouble cases cited, “continuity check” will be directed for some harnesses. This direction applies also to “check the connector coupling”: when checking a connector as in (d), above, be sure to check the connector for circuit continuity immediately after coupling it.

Component

(f) When reading a voltage with a circuit tester, be sure to discriminate polarities, (+) and (–), so that the tester will not suffer internal damage.

Trouble symptom

Control levers

Short-circuit

Solenoid valves

Short-circuit, oil leakage

NOTE For the method of deleting the data stored in the controller, refer to (a) thru (e), 1. (4).

(g) Trouble data stored in the controller, as explained in 1. (4), can be read out by the GSE. Such a read-out is the “data on trouble as was” and must not be interpreted as data on the trouble confirmed to exist. To illustrate this point, assume that the data are currently displayed in the form shown on the right and that the indicated faulty conditions have already been corrected by repair. In this case, the work attachment in question remains inoperative. Thus, it is important that, each time a detected malcondition is corrected and eliminated, the trouble data be changed promptly to reflect the correction effected. 3-36


ELECTRICAL SYSTEM

(h) Not withstanding what is said in (g), above, the “data on past trouble,” as read into the GSE from the controller, can be useful information in checking for such malconditions (like an open due to loose contact in a circuit) as may not show up later at the time of performing a troubleshooting work. The diagram, below, illustrates and example of precarious type of malcondition:

The malcondition on the left, detected at the time of trouble occurrence, will go into the data as “opencircuit” if it happens to present an open. Trouble symptom data

Open-circuit

Supposing that, as you start the troubleshooting work with the GSE, the near-open fault happens to be in a precariously closed condition: then, the GSE will indicate the circuit of the device in question as normal whereas the data held in the controller reads “open-circuit” for that device. Trouble symptom data

Device

Past

Open-circuit

Now

Normal 208790

3-37


Clearance lamp

Head lamp

Tail lamp

Auto-light system schematic

Light sensor

B

3-38 10 A

Starter switch

Lighting switch

Power relay

20 A Auto-light switch OFF ON

P H T

Console box

Instrument panel lamp

184

201

173

Battery

177

Safety switch

169

Control (joystick) box

ON or OFF signal

Power supply

Setting window

Controller

Bright

208791

Dark

169 177 173 184

182 183 186 187

Turn-On

Auto-light sensitivity adjusting knob

NOTE: Circuit Nos. are indicated by small-character numbers.

ELECTRICAL SYSTEM

(2) Auto-light System Troubleshooting


ELECTRICAL SYSTEM

(a) Case 1: Head lamps will not go ON in darkness. Troubleshooting procedure

Is the LED (red) ON in the controller?

No

Refer to Case 7: “Controller’s LED (red) will not go ON.”

Yes

Set the sensitivity to make the lamps turn ON at the desired degree of darkness.

Yes

Check CN51, CN52 and CN53 for continuity. If these connectors are OK, it means that the controller is in faulty condition and needs to be replaced.

No

Check the circuits of power relay and auto-light switch (in the console box) for continuity. As necessary, repair or replace.

Yes Do the head lamps go ON when the sensitivity is re-adjusted? No Do the head lamps go ON when circuit 173 (CN51) is grounded (shorted to the ground)? (Does this shorting cause the power relay to trip ?) No Have circuit 184 shorted to circuit 201 at the male side of CN4. Then, ground circuit 173 : will this turn ON the head lamps? Yes Check harness B for continuity and repair faulty part or line, if any.

3-39


ELECTRICAL SYSTEM

(b) Case 2: Head lamps will not go OFF when bright. Troubleshooting procedure

Is the LED (red) ON in the controller?

No

Refer to Case7: “Controller’s LED (red) will not go ON.”

Yes

Set the sensitivity so that the lamps will go OFF at the desired degree of darkness.

Yes

Is the resistance through CN52 (between circuits 177 and 169 ) less than 20 kilohms?

Yes Do the head lamps go OFF when the sensitivity is re-adjusted? No Do the head lamps go OFF when CN51 is disconnected? No

No Check the light sensor circuit for continuity and repair or replace.

Do the head lamps go OFF when CN4 is disconnected? No

Yes

Yes

Check CN51, CN52 and CN53. If these connectors are OK, it means the controller is in faulty condition and needs to be replaced.

Check power relay and auto-light switch (in the console box) for shortcircuit, and repair or replace.

See if circuit 173 of harness B is shorted to chassis or to ground circuit and, if so, repair.

3-40


Lift cylinder

3-41 Hydraulic pump

Unload solenoid

10 A

System indicator light Starter switch

Console box

Control system schematic

Control valve unit

Seat switch

Flow control signal

Proportioning solenoid

Control Lowering speed lever selector switch Safty (joystick) switch

Control (joystick) box

Setting window

Controller

On or OFF signal

ON or OFF signal Lever position signal

Power supply

208792

ELECTRICAL SYSTEM

(3) Control System Troubleshooting


ELECTRICAL SYSTEM

(a) Case 3: No motion of hydraulic cylinders. Troubleshooting procedure

Is the system check lamp ON or OFF?

OFF

Yes Move the control lever: does throttling The control valve noise or any other abnormal noise come Yes is internally in from the control valve? (Does the faulty condition. unload solenoid operate?)

Stays ON or flickers Re-set.

No

Is the controller set to match the machine specification?

Yes Connect the GSE to the controller and read out the current trouble data. Use GSE to monitor trouble.

Flicker

No Is the controller’s LED (red) ON or OFF? Stays ON

Are all levers normal?

Are all input trouble data (on a lever), as read by the GSE, normal? Yes Are all output trouble data (on the sensor), as read, normal? Yes Are all output trouble data (standard), as read, normal? Yes Are all output trouble data (on the work attachment), as read, normal? (This does not apply to the two-element control valve unit.)

No Turn OFF safety switch.

Is safety switch off ?

Refer to case 8.

Stays OFF Refer to case 7.

No

Check the harness and connectors of the lever in question for continuity. If open-circuit condition is noted, replace the lever assembly.

No

Check for continuity the harness and connectors of the component in question. If open-circuit is noted, replace the component.

No

No

Check for continuity the harness and connectors of the solenoid in question. If open-circuit is noted, replace the solenoid. (Refer to the section on solenoid control valves.)

Yes Read the past trouble data into the GSE.

No

Check for continuity the harness and connectors of the lever in question. If short-circuit is noted, replace the lever assembly.

Yes Are all input trouble data (on the sensor), as read, normal?

No

Check for continuity the harness and connectors of the component in question. If short-circuit is noted, replace the component.

Yes Are all output trouble data (standard), as read, normal?

No

Yes Are all output trouble data (on the attachment), as read, normal?

No

Are all input trouble data (on the lever), as read, normal?

Check for continuity the harness and connectors of the solenoid in question and, if short-circuit is noted, replace the solenoid. (Refer to the section on solenoid control valves.)

Yes To deal with an internal malcondition of any solenoid control valve, refer to the section on solenoid control valves. If necessary, contact the manufacturer. 3-42


ELECTRICAL SYSTEM

(b) Case 4 : No inching motion of hydraulic cylinders Troubleshooting procedure

Does abnormal noise issue out when the mast is operated with normal working speed?

Yes

Check for hitching, sticking and rattling. Repair to smoothen the movements.

No Is the controller set to match the machine specifications?

No

Re-set.

Yes Connect the GSE to the controller and read “Input condition� into the GSE. Check to be sure that the data, as read, indicate the control lever 76 HEX to 8A HEX.

Move the control levers slowly back and forth and check that indication varies continuously between 0 and 100%. Test the control lever, as above, twice or thrice, to be sure there is no jump or dip in the rising indication.

No

The cause is a malcondition within the solenoid control valve. If necessary, contact the manufacturer.

Yes Check the harness and connectors of the lever in question for continuity. If discontinuity is noted, replace the lever assembly.

3-43


ELECTRICAL SYSTEM

(c) Case 5: The maximum lowering speed of the mast is too high (or too low). Troubleshooting procedure

Is the controller set to match the machine specifications?

No

Re-set.

Yes Is the adjusting knob (for the max. lowering speed of the mast) effective in adjusting this speed of the mast?

Yes

(End)

No Connect the GSE to the controller and read out “Input condition� into the GSE.

Does the indication on the output monitor screen vary between 0 and 100% as the lever angle is changed?

No

The lever is faulty or there is something wrong with the harness.

No

The controller is faulty or there is something wrong with the harness.

Yes Are there changes in current of the order of 0.4 to 0.9 A? Yes The solenoid valve is faulty or there is something wrong with the harness.

3-44


ELECTRICAL SYSTEM

(d) Case 6: During the lowering action of a lift cylinder differ in actuating speed. Troubleshooting procedure

Is the controller set to match the machine specifications?

No

Re-set.

Yes Connect the GSE to the controller and read out “Input state (2)� into the GSE.

Operate the mast: see if the lift cylinder indication make an ONto-OFF change when 2nd cylinder starts rising from its fully retracted position. Will the change occur? (Test twice or thrice to be sure of the lift cylinder action.)

Yes

Contact the manufacture.

No Check for continuity the harness and connectors of the lift cylinder circuit. As necessary, replace the lift cylinder.

3-45


ELECTRICAL SYSTEM

(e) Case 7: Controller’s LED (red) will not go ON. Troubleshooting procedure

Check the fuse. Is the fuse OK or NG?

NG

Replace the fuse, and check the harnesses for open or short.

No

Is the voltage between circuit 201 on the male side of CN4 and ground at least 10 volts?

OK Read the voltage between ground and circuits 182 and 183 (CN53). Is the reading at least 10 volts? (Is power being supplied to the controller?)

Yes

Yes

Check the power supply circuit (inside the console box) for continuity. Repair and correct an open if any.

Is there continuity between circuits 186 and 187 and the ground? Yes

No

No Is there continuity between circuit 201 (on the female side of CN4) and circuits 182 and 183 (at CN53)?

Check to be sure that CN51, CN52 and CN53 are all in sound condition. If the trouble persists, replace the controller.

Check harness B for continuity. Repair and correct an open, if any.

Yes

No

While making sure that each connector is coupled up tight, check to see if the LED turns ON; if not, contact the manufacturer. Yes

Is there continuity between circuits 183 and 201 at the male side of CN54? No Check the safety switch and engine hood harness for open-circuit. Repair and correct an open if any, or replace the switch as necessary.

3-46


ELECTRICAL SYSTEM

(f) Case 8: Controller’s LED (red) will remain ON. Troubleshooting procedure

Does the LED remain OFF, indicating the power supply is faulty?

No

Is the voltage between circuit 201 on the male side of CN4 and ground at least 10 volts? Yes

No Check the power supply circuit (inside the console box) for continuity. Repair and correct an open if any.

Is the resistance between circuit 201 (on the female side of CN4) and circuits 182 and 183 (at CN53) less than 0.1 ohm? Yes

No

While making sure that each connector is coupled up tight, check to see if the LED turns ON; if not, contact the manufacturer. Check harness B for continuity. Repair and correct an open, if any.

Yes

If the resistance between circuits 183 and 201 on the male side of CN54 less than 0.05 ohm? No Check the safety switch and engine hood harness for open-circuit. Repair and correct an open if any, or replace the switch as necessary.

If the LED remains ON; Are the DIP switches correctly set? Is the SW2-8 set OFF?

No Re-set.

Yes Replace the controller.

3-47


ELECTRICAL SYSTEM 4. How to Move the Mast in an Emergency

If the truck fails while at work and, you then have to drive it (if the engine is OK) or tow it to some distant place or to the repair shop, do the following steps: (1) Mast lowering (a) Loosen lock nut 1 on the lift section of the contrl valve. (b) Using an Allen wrench, slowly loosen screw 2. This causes the mast to go down by gravity: tighten screw 2 and the mast will stop.

CAUTION Before doing these steps, be sure that there is no one standing under the mast. 205008

(c) Tighten lock nut 1.

CAUTION Leaving nut 1 loose is dangeraous: the mast might suddenly start going down by itself.

(2) Lifting, tilting or auxiliary function

CAUTION Steps (a) thru (i), below, are dangerous for the following actions:

Action

Remarks

Lowering the mast

Mast will move in free-falling manner.

Dumping the hinged fork (or bucket) Dumping the dump fork (or bucket)

Jerky dumping action. (The load will fall off.)

Releasing clamped load

The load will fall.

3-48


ELECTRICAL SYSTEM

(a) Remove the unload solenoid connector of the control valve. Remove the proportional solenoid connector on that end of the control valve which is for the action you need. (b) Using a circuit tester, check the two solenoids (unload solenoid and proportional solenoid) for short or open. The faulted solenoid, if any, must be replaced by a new one at this time. (If the proportional solenoid, from which you pulled off the connector half, is faulty, you may replace it temporarily by another solenoid in place on the control valve.)

Proportioning solenoid connectors Tilt forward Mast down

Attachment 1 Attachment 2

Operates when lever is pushed.

From bottom to top

Unload solenoid connector Mast up Tilt backward

Operates when lever is pushed. Attachemnt 2 Attachment 1

Proportioning solenoid connectors

208793

(c) To the two connector halves, from which the female halves were disconnected in step (a), above, couple the female halves of the emergency-use harness (special tool), as shown. Special tool needed Emergency-use harness

91105 - 00400

(d) Connect the “black� alligator clip (of the other end of the harness) to the negative (–) terminal of the battery: have the other (red) alligator clip put on the harness, as shown. (e) Start up the engine.

3-49

205010


ELECTRICAL SYSTEM

(f) Hold the engine in idling condition. Look around the machine to be sure no one stands near the truck. Now, take off the “red” alligator clip and touch the battery’s positive (+) terminal with it: as you do so, the action you need (corresponding to that of the proportional solenoid now connected to the battery) will start: the action will stop as you remove the “red” clip from the terminal.

CAUTION (1) Do not keep touching the battery terminal (+) with the “red” alligator clip, or the solenoid will get burned. Touch intermittently. (2) You may raise the engine speed while intermittently energizing the solenoid but do so cautiously, keeping an eye on the action in progress.

(g) If the desired action does not occur in step (f), above, it means that there is some malcondition inside the control valve. (h) Stop the engine, and remove the emergency-use harness. (i) Re-couple the connectors of unload solenoid and proportioning solenoid.

3-50

205011


ELECTRICAL SYSTEM

(3) How to cope with a failed (open-circuited) seat switch Your troubleshooting investigation might reveal that the seat switch is open-circuited or otherwise faulted and will not function. In such a case, you can create a temporary circuit continuity through the seat switch line. The method is explained in this illustration. The seat switch is a security part. Be sure to replace it by a new one as soon as possible.

Two connectors are in the seat switch line at the indicated location. Open these connectors, and couple up the male and female connector halves to form a circuit bypassing the seat switch.

208794

CAUTION Illustrated above is a first-aid method permissible only in an emergency situation. Be sure to restore the seat switch line to the normal hookup after replacing the failed switch.

3-51


ELECTRICAL SYSTEM 5. How to Clean Harness Connectors and System Components

(1) Open-circuit trouble is often due to the harness connectors and components in dirty condition: dust, together with greasy matter, forms grime which, in time, penetrates electrical connections, resulting in loose metal-to-metal contact or, for worse, electrical separation of surfaces in contact. For this reason, it is essential that the connectors and components be cleaned at each periodic inspection and at the time of servicing the machine. Instead of a commonly used solvent, use electronic parts cleaner (in the manner illustrated on the right). Electronic parts cleaner

208795

ThreeBond 29B

NOTE The cleaner liquid is volatile. All you have to do is just give a strong spray to wash off grime. No need to wipe off the sprayed liquid.

(2) After checking the connector for continuity, wash it as above. Then, uncouple the connector and spray contact surface activator onto contact surfaces. Now, install and remove the connector several times to wet the surfaces thoroughly with the activator liquid. After coupling up the connector so sprayed on, check to be sure that it is in locked state.

Contact surfaces activator

ThreeBond 2501S (aerosol)

NOTE Do not spray too much: bear in mind that this spray liquid reacts with some resins (plastic materials).

205047

3-52


ELECTRICAL SYSTEM 6. Troubleshooting Guide for Solenoid Control Valves

Trouble symptoms

Possible causes

The pump discharge pressure will not build up

Remedies

1. Unload solenoid not working 2. Sticky plunger in proportioning solenoid of reducing valve, or sticky shuttle in reducing valve 3. Open in lead wire or in solenoid coil 4. Input current to solenoid too small 5. Unload valve stuck open 6. Spool stuck in flow-divider valve

Sticky spool

Sticky plunger in proportioning solenoid of reducing valve, or sticky shuttle in reducing valve.

Disassemble and clean by washing. Replace solenoid as necessary. Disassemble and clean by washing. If the plunger is sticky, replace the solenoid. Repair or replace. Check to make sure that solenoid is drawing specified maximum input current. • Check unload solenoid for action. • Check unload valve for action. Disassemble and clean by washing. Disassemble and clean by washing. If plunger is sticky, replace solenoid.

7. Troubles Conceivable for Each Component LED ON-OFF pattern

Threshold

Normal

A

Control levers are not in their neutral positions when power supply is turned on.

D

128 ± 10 (A/D value)

Turn off corresponding Flash solenoids’ outputs.

Input level is higher than lever maximum position level.

B

245 to 255 (A/D value)

Turn off corresponding ON solenoids’ outputs.

Short circuit

Input level is lower than lever minimum position level.

B

0 to 10 (A/D value)

Turn off corresponding ON solenoids’ outputs.

Open circuit

Abnormal if current is 0 when solenoid output is ON.

C

120 mA or lower

Turn off abnormal solenoid’s output.

ON

Short circuit

Abnormal if solenoid output current level is higher than threshold level.

C

2.4 A or higher

Turn off abnormal solenoid’s output.

ON

Leakage

Abnormal current is detected during emergency operation.

C

140 mA or higher

Turn off all solenoids’ ON outputs.

4 Seat switch

Open circuit

Check I/O levels. Abnormal if signal stays OFF.

E

OFF for 15 seconds or longer

Turn off all solenoids’ Flash outputs.

5 CPU

Abnormality

(CPU does not run.) (WDT causes CPU reset.)

F

6 Battery voltage

Voltage drop, Voltage is out of specification overvoltage

C

Lower than 10 V; Turn off all solenoids’ ON higher than 32 V outputs.

7 Setting switch

Check mode

G

S1 ON

1

Component

Trouble

2 Control levers Not in neutral (1) Lift lever (2) Tilt lever (3) Attachment 1 lever Open circuit (4) Attachment 2 lever

3 Solenoids (1) Lift (2) Tilt (3) Attachment 1 (4) Attachment 2

Condition

Setting of SW 2 (DIP switch)

3-53

Action No action

System check lamp OFF

Turn off all solenoids’ Irregular outputs.

Start check mode operation (solenoid operation)

(OFF)


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Caterpillar cat gp40k forklift lift trucks chassis and mast service repair manual sn:et29b 00011 and  
Caterpillar cat gp40k forklift lift trucks chassis and mast service repair manual sn:et29b 00011 and  
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