UTILEV Forklift Truck 285 UT20P, UT25P, UT30P, UT35P Service Manual - PDF DOWNLOAD

B285 UTILEV SERVICE MANUAL UT20P, UT25P, UT30P, UT35P

PART NO. 76007600

INTRODUCTION The Service Manuals are updated on a regular basis, but may not reflect the latest design changes to the product.

Updated technical service information may be available from your local authorized UTILEV® distributor. Service Manuals provide general guidelines for maintenance and service and are intended for use by trained and experienced technicians. Failure to properly maintain equipment or to follow instructions contained in the Service Manual could result in damage to the products, personal injury, property damage or death.

FOREWORD This manual describes the structure and working principles of the 2-3.5T internal combustion forklift truck and provides instructions for servicing and maintenance.

To ensure safety and get the best out of your forklift, all operators, equipment managers and maintenance personnel should carefully read this manual.

Only trained and qualified personnel are permitted to carry out servicing and repairs on the forklift truck.

Series

2-2.5T

2-2.5T

Model

Engine

Transmission

UT20/25P-W(B2)3

NISSAN K21 LPG

YQXD30H(PHF)

UT20/25P-W(B3)3

NISSAN K21 GAS

YQXD30H(PHF)

UT20/25P-W(B1)3

NISSAN K21 DUAL

YQXD30H(PHF)

UT20/25P-W(A2)3

NISSAN K25 LPG

YQXD30H(PHF)

UT20/25P-W(A3)3

NISSAN K25 GAS

YQXD30H(PHF)

UT20/25P-W(A1)3

NISSAN K25 DUAL

YQXD30H(PHF)

UT20/25P-WV3

MITSUBISHI S4S-455

YQXD30(PHF)

Series

3-3.5T

Model

Engine

Transmission

UT20/25P-W(G1)3

PSI 4G64 2.4L

YQXD30(PHF)

UT20/25P-G(1)3

XINCHAI 4D27G31

YQXD30A(PHF)

UT20/25P-WC3

YANMAR 4TNE92

YQXD30(PHF)

UT30/35P-W(A2)3

NISSAN K25 LPG

YQXD30H(PHF)

UT30/35P-W(A3)3

NISSAN K25 GAS

YQXD30H(PHF)

UT30/35P-W(A1)3

NISSAN K25 DUAL

YQXD30H(PHF)

UT30/35P-WV3

MITSUBISHI S4S-455

YQXD30(PHF)

UT30/35P-W(G1)3

PSI 4G64 2.4L

YQXD30(PHF)

UT30/35P-G(1)3

XINCHAI 4D27G31

YQXD30A(PHF)

UT30/35P-W(8)3

YANMAR 4TNE94

YQXD30(PHF)

UT30/35P-WE3

YANMAR 4TNE98

YQXD30(PHF)

NOTE: DUAL designates DUAL FUEL or BI-FUEL.

Table of Contents

TABLE OF CONTENTS Forklift Main Technical Parameters ...........................................................................................................................2 Main Technical Parameters ...................................................................................................................................2 Power System ...........................................................................................................................................................7 Engine System ......................................................................................................................................................7 Engine Overview ...............................................................................................................................................7 Fuel System ...................................................................................................................................................... 9 Fuel Tank .......................................................................................................................................................9 Fuel Level Sensor ....................................................................................................................................... 10 Maintenance of Fuel System .......................................................................................................................11 Fuel filter service ..................................................................................................................................... 11 Hydraulic Transmission Case and Torque Converter ............................................................................................. 12 Overview ............................................................................................................................................................. 12 Torque Converter ................................................................................................................................................ 14 Hydraulic Clutch ..................................................................................................................................................15 Control Valve, Safety Valve, and Inching Valve .................................................................................................. 16 Transmission Case ............................................................................................................................................. 17 Transmission Pump ............................................................................................................................................ 17 Transmission hydraulic schematic ...................................................................................................................... 18 Speed Reducer and Speed Differential .............................................................................................................. 20 Speed Reducer ............................................................................................................................................... 20 Speed Differential ............................................................................................................................................20 Towing the Lift Truck ........................................................................................................................................... 20 Oil Inlet/Outlet Connection Location ................................................................................................................... 20 Drive Axle ................................................................................................................................................................22 Overview ............................................................................................................................................................. 22 Maintenance of Drive Axle .................................................................................................................................. 23 Steering System ..................................................................................................................................................... 24 Steering System ..................................................................................................................................................24 Overview ......................................................................................................................................................... 24 Hydraulic Steering Gear Assembly ............................................................................................................. 24 Steering Cylinder .........................................................................................................................................26 Inspection of Reassembled Steering System ................................................................................................. 27 Troubleshoot Steering System ........................................................................................................................27 Steering and Drive Axle Information ....................................................................................................................... 28 Steering Axle .......................................................................................................................................................28 Overview ......................................................................................................................................................... 28 Steering Knuckle and Steering King Pin ......................................................................................................... 30 Steering Wheel Bearing Pre-load Information .................................................................................................30 Brake System ......................................................................................................................................................... 31 Overview ............................................................................................................................................................. 31 Brake Master Cylinder ........................................................................................................................................ 31 Wheel Brake ....................................................................................................................................................... 32 Automatic Brake Adjuster ................................................................................................................................... 36 Manual Brake ......................................................................................................................................................37 Adjustment of Brake Pedal ................................................................................................................................. 37 Maintenance ....................................................................................................................................................... 38 Disassemble, Wheel Brake .............................................................................................................................38 Examination of Wheel Brake ...........................................................................................................................40 Assemble, Wheel Brake ..................................................................................................................................41 Operating Test Automatic Clearance Regulator ..............................................................................................43 Troubleshoot Wheel Brake ..............................................................................................................................44 Hydraulic System ....................................................................................................................................................46 ©2022 UTILEV

i

Table of Contents

TABLE OF CONTENTS (Continued) Overview ............................................................................................................................................................. 47 Steering Control Unit ...........................................................................................................................................47 Multi-way Valve and Priority spool ...................................................................................................................... 47 Operation of Spool Valve ................................................................................................................................ 48 Neutral Position ...........................................................................................................................................48 Spool Valve (Pushed In): .............................................................................................................................48 Spool Valve (Pulled out): .............................................................................................................................48 Primary Relief Valve and Priority Spool .......................................................................................................... 49 Inclined Auto-Lock Valve .................................................................................................................................50 Hydraulic System Main Oil Circuit .......................................................................................................................50 Lift Cylinder ......................................................................................................................................................... 53 Velocity Fuse .......................................................................................................................................................55 Tilt Cylinder ......................................................................................................................................................... 56 Maintenance of Hydraulic Pump ......................................................................................................................... 57 Disassemble, Main Oil Pump ..........................................................................................................................57 Inspection and Repair ..................................................................................................................................... 57 Assemble, Main Oil Pump ...............................................................................................................................59 Test ..................................................................................................................................................................60 Troubleshoot Hydraulic System .......................................................................................................................... 65 Lifting System ......................................................................................................................................................... 66 Safety Procedures When Working Near Mast .................................................................................................... 66 Overview ............................................................................................................................................................. 68 Inside and Outside Masts ................................................................................................................................... 70 Carriage .............................................................................................................................................................. 70 Adjustment of Lifting System .............................................................................................................................. 70 Electrical System .................................................................................................................................................... 72 Overview ............................................................................................................................................................. 72 Power supply system ...................................................................................................................................... 72 Starting system ............................................................................................................................................... 72 Ignition system (ICE forklift truck) ................................................................................................................... 72 Preheating system (diesel forklift truck) .......................................................................................................... 72 Dash Instrument Display system .....................................................................................................................72 Lighting, sound and alarm system .................................................................................................................. 72 Electrical Box ...................................................................................................................................................... 72 Battery .................................................................................................................................................................72 Description and Summary of Basic Truck Operations ........................................................................................ 73 Introduction to the Power Distribution Module (PDM) .........................................................................................74 Electrical Schematics ..........................................................................................................................................74 Troubleshoot Electrical System ...........................................................................................................................88 Troubleshooting .............................................................................................................................................. 88 Drive, Operation, and Routine Maintenance of Forklift Truck ................................................................................. 90 Cooling System Troubleshooting and Service .................................................................................................... 90 Coolant level check .........................................................................................................................................90 Flushing the cooling system ............................................................................................................................90 Adding antifreeze/coolant ................................................................................................................................90 Cleaning the radiator .......................................................................................................................................90 Oils Used for Forklift Truck ..................................................................................................................................91 Hydraulic Oil Gauge and Hydraulic Oil fill ........................................................................................................... 91 General inspection requirements .................................................................................................................... 91 Fill Level Requirements ...................................................................................................................................91 Lubrication System ............................................................................................................................................. 91 PDM Schematics .................................................................................................................................................... 92 ii

Table of Contents

iii

1

Forklift Main Technical Parameters

Forklift Main Technical Parameters MAIN TECHNICAL PARAMETERS See Table 1 through Table 2

Figure 1. Outside Drawing of Forklift Truck(LPG/DUAL)

2

Forklift Main Technical Parameters

Figure 2. Outside Drawing of Forklift Truck (Diesel engine/gasoline engine) NOTE: Truck with diesel engine is shown. Other trucks are similar. The values in the parameter tables

are for standard configuration only. Always consult the nameplate to see the values of a specific truck.

Table 1. Technical Parameters Parameter

Model H2.0UT

H2.5UT

Engine Model

4G64 2.4L

4G64 2.4L

Manufacturer

PSI

PSI

Power Source

GAS/LPG

GAS/LPG

Rated Capacity

2000 kg (4409.2 lb)

2500 kg (5511.6 lb)

3

Forklift Main Technical Parameters

Table 1. Technical Parameters (Continued) Parameter

Model H2.0UT

H2.5UT

Load Center

500 mm (19.7 in.)

500 mm (19.7 in.)

Lifting Height

3000 mm (118.1 in.)

3000 mm (118.1 in.)

Free Lift Height

160 mm (6.3 in.)

160 mm (6.3 in.)

Mast Tilt Angle Forward/Back

6/12°

6/12°

No-Load

580 mm/s (1.9 ft/s)

580 mm/s (1.9 ft/s)

Full-Load

550 mm/s (1.8 ft/s)

550 mm/s (1.8 ft/s)

Forward

20 kph (12.4 mph)

20 kph (12.4 mph)

Back

20 kph (12.4 mph)

20 kph (12.4 mph)

No-Load

15000 N (3372.1 lbf) N ( lbf)

15000 N (3372.1 lbf)

Full-Load

17000 N (3821.8 lbf)

17000 N (3821.8 lbf)

No-Load

20%

20%

Full-Load

20%

20%

Min Turning Radius

2290 mm (90.2 in.)

2350 mm (92.5 in.)

Minimum Turning Radius Width K

3966 mm (156.1 in.)

4026 mm (158.5 in.)

Total Length L （Without Fork）

2535 mm (99.8 in.)

2596 mm (102.2 in.)

Total Width W

1150 mm (45.3 in.)

1150 mm (45.3 in.)

Total Height D （Mast Retracted）

2010 mm (79.1 in.)

2010 mm (79.1 in.)

Total Height E （Mast Extended）

3990 mm (157.1 in.)

3990 mm (157.1 in.)

Wheelbase F

1600 mm (63 in.)

1600 mm (63 in.)

Front Q1

970 mm (38.2 in.)

970 mm (38.2 in.)

Front Q2

980 mm (38.6 in.)

980 mm (38.6 in.)

Front Overhang B

476 mm (18.7 in.)

476 mm (18.7 in.)

Rear Overhang C

484 mm (19.1 in.)

545 mm (21.5 in.)

Length

1070 mm (42.1 in.)

1070 mm (42.1 in.)

Width

100 mm (3.9 in.)

100 mm (3.9 in.)

Height

40 mm (1.6 in.)

40 mm (1.6 in.)

Fork Spacing Adjustable Range

250-1000 mm (9.8-39.4 in.)

250-1000 mm (9.8-39.4 in.)

Ground Clearance （Bottom Of Mast）

125 mm (4.9 in.)

125 mm (4.9 in.)

Total Weight

3390 kg (7474 lb)

3650 kg (8046.9 lb)

Max Lifting Speed Running Speed Max Traction Force

Gradeability

Track Width

Fork Dimension

4

Forklift Main Technical Parameters

Table 2. Technical Parameters Parameter

Model H3.0UT

H3.5UT

Engine Model

4G64 2.4L

4G64 2.4L

Manufacturer

PSI

PSI

Power Source

GAS/LPG

GAS/LPG

Rated Capacity

3000 kg (6613.9 lb)

3500 kg (7716.2 lb)

Load Center

500 mm (19.7 in.)

500 mm (19.7 in.)

Lifting Height

3000 mm (118.1 in.)

3000 mm (118.1 in.)

Free Lift Height

165 mm (6.5 in.)

170 mm (6.7 in.)

Mast Tilt Angle Forward/Back

6/12°

6/12°

No-Load

470 mm/s (1.5 ft/s)

410 mm/s (1.9 ft/s)

Full-Load

440 mm/s (1.4 ft/s)

380 mm/s (1.2 ft/s)

Forward

21 kph (13 mph)

21 kph (13 mph)

Back

21 kph (13 mph)

21 kph (13 mph)

No-Load

15000 N (3372.1 lbf) N ( lbf)

15000 N (3372.1 lbf)

Full-Load

17000 N (3821.8 lbf)

17000 N (3821.8 lbf)

No-Load

18%

18%

Full-Load

18%

18%

Min Turning Radius

2430 mm (95.7 in.)

2500 mm (98.4 in.)

Minimum Turning Radius Width K

4121 mm (162.2 in.)

4210 mm (165.7 in.)

Total Length L （Without Fork）

2663 mm (104.8 in.)

2748 mm (108.2 in.)

Total Width W

1210 mm (47.6 in.)

1210 mm (47.6 in.)

Total Height D （Mast Retracted）

2075 mm (81.7 in.)

2150 mm (84.6 in.)

Total Height E （Mast Extended）

4100 mm (161.4in in.)

4100 mm (161.4in in.)

Wheelbase F

1700 mm (66.9 in.)

1700 mm (66.9 in.)

Front Q1

1000 mm (39.4 in.)

1000 mm (39.4 in.)

Front Q2

980 mm (38.6 in.)

980 mm (38.6 in.)

Front Overhang B

491 mm (19.3in in.)

510 mm (20.1 in.)

Rear Overhang C

502 mm (19.8 in.)

573 mm (22.6 in.)

Length

1070 mm (42.1 in.)

1070 mm (42.1 in.)

Width

122 mm (4.8 in.)

122 mm (4.8 in.)

Height

45 mm (1.8 in.)

50 mm (2 in.)

Fork Spacing Adjustable Range

250-1060 mm (9.8-41.7 in.)

260-1060 mm (10.2-41.7 in.)

Max Lifting Speed Running Speed Max Traction Force

Gradeability

Track Width

Fork Dimension

5

Forklift Main Technical Parameters

Table 2. Technical Parameters (Continued) Parameter

6

Model H3.0UT

H3.5UT

Ground Clearance （Bottom Of Mast）

140 mm (5.5 in.)

140 mm (5.5 in.)

Total Weight

4300 kg (9479.9 lb)

4710 kg (10383.8 lb)

Power System

Power System ENGINE SYSTEM NOTE: Engine availability may be different in your market. Contact your local Hyster dealer for more information.

Engine Overview Refer to Table 3 for the imported DUAL FUEL and LPG used for 2.0-3.5t forklift trucks in A series.

Table 3. Gasoline Engine (2.4) Model

PSI 4G64-2.4L

Type

4-Stroke, Water-Cooling, Straight-Line, and Valve in Head

Number of Cylinders

4

Cylinder Diameter × Stroke

86.5 × 100 mm (3.41 × 3.94 in.)

Total Displacement I

2.35 liter (143.4 in.3)

Compression Ratio

9.5

Gasoline Engine Rated Power/ Speed kw(ps)/rpm LPG Engine

Gasoline Engine Max Torque/Speed LPG Engine

48/2700（kw/rpm） 64.4/2700（hp/rpm） 46/2700（kw/rpm） 61.7/2700（hp/rpm） 170/2400（N.m/rpm） 125.4/2400（lbf·ft/rpm） 168/1600（N.m/rpm） 123.9/1600（lbf·ft/rpm）

No-Load Min Speed

750 rpm

Fuel Specific Consumption

290 g/psh (.096 g/hph)

Total Length × Total Width × Total Height

677.4 × 543.6 × 711.0 mm (26.7 × 21.4 × 28.0 in.)

Movement Direction

In Clockwise Direction Looking from the End of Fan

Firing Order

1-3-4-2

7

Power System

Table 3. Gasoline Engine (2.4) (Continued) Model

Valve Timing

PSI 4G64-2.4L

Inlet Valve Open before Top Dead Center (BTDC)

8°

Inlet Valve Close after Bottom Dead Center (ABDC)

48°

Exhaust Valve Open before Bottom Dead Center (BBDC)

31°

Exhaust Valve Close after Top Dead Center (ATDC)

36°

Timing belt change interval

6000 hrs

Cooling System

Forced Circulation Water Cooling

Lubricating System

Forced Lubrication

Gasoline Pump

Membrane Type

Air Filter

Paper Element Filter

Engine Oil Pump

Gear Type

Oil Rough Filter

Paper Filtration

Water Pump

Centrifugal Type

Thermostat

Wax Type

Generator Starter Battery

Voltage

12V

Current

70A

Voltage

12V

Output Power

1.2 kW (1.61 hp)

Voltage

12V

Capacity

60Ah Referential Data

Lubricating Oil Coolant

Engine

3.5 liter (3.7 qt)

Radiator

3.5 liter (3.7 qt)

Refer to the engine operation and maintenance manuals for more information about engines used for 2-3.5t forklift trucks.

8

4.5 liter (4.7 qt)

Power System

Fuel System

Fuel Tank

Fuel system is composed of fuel tank, fuel quantity sensor, and fuel quantity indicator. See Figure 5 and Figure 6.

The fuel tank is a welded structure contained within the frame of the forklift truck. The capacity of fuel tank for 2-2.5t is 59 liter (15.6 gal), and 65 liter (17.2 gal) for 3-3.5t forklift trucks. The Fuel Level Sensor is fitted on the tank cover of fuel tank to detect the fuel level. See Figure 3 or Figure 4.

1. PORT SEALED 2. FUEL LEVEL

3. FLOAT RISE 4. FLOAT DROP

5. OIL INLET 6. GAS FILTER

Figure 3. Fuel Tank (Gasoline Forklift Truck)

9

Power System

Figure 4. Fuel Tank (LPG Forklift Truck)

Fuel Level Sensor The Fuel Level Sensor is used to convert the remaining fuel quantity in fuel tank into voltage. This is to monitor the amount of fuel currently in the fuel tank.

Refer to Figure 5. The value of resistance will change when the float moves up and down, depending on the fuel level. Resistance is controlled by using steel wire that is fabricated into the slide. The fuel quantity inside the fuel tank can be read on the instrument panel through the electromagnetic fuel gauge.

1. FUEL LEVEL 2. FLOAT RISE 3. FLOAT DROP Figure 5. Fuel Level Sensor

10

Power System

Fuel Position

Resistance (Ω)

FULL

180±5

½

95±5

EMPTY

10±½

Maintenance of Fuel System The fuel system is to be maintained and serviced once for every 100 work hours, with the following method.

The fuel tank must be cleaned once every 600 work hours.

Fuel filter service The fuel filter is used to remove dust and impurities in fuel. The fuel filter is located between the fuel tank and the gasoline pump (gasoline engine) or oil delivery pump and oil injection pump (diesel engine).

1.

2.

3.

4.

5.

6.

7.

STEEL TUBE CLAMP FUEL FILTER HIGH PRESSURE FUEL PUMP FUEL PUMP FITTING AND GASKET FUEL PUMP MANIFOLD 6 STOR 5/16 SAE FITTING 3 STOR 5/16 SAE FITTING Figure 6. Fuel Filter (PSI 4G64-2.4L Engine)

The fuel filter must be changed every 400 hours or every 6 months.

11

Hydraulic Transmission Case and Torque Converter

Hydraulic Transmission Case and Torque Converter

Torque Converter

Oil Feed Pump

Type

Three-Element, Single-Stage, and Two-Phase Type

Torque Ratio

2.8-3.0:1

Pressure Range

0.5-0.7 MPa (72.5-101.5 psi)

Type

Internal Meshing Gear Type

Flow Rate

27 l/min (1.5 MPa x 2000 rpm) 7.1 g/min (217.6 psi x 2000 rpm)

Type Hydraulic Transmission Case

Speed Ratio

Power Gear Shift Forward

17.5:1

Reverse

17.5:1

Pressure Range

1.2 to 1.5 MPa (174 to 218 psi)

Brake Shoes Outer Diameter x Inner 125 x 81 x 2.7 mm (4.9 x 3.2 x Diameter x Thickness 0.1 in.)

Hydraulic Clutch

Brake Shoes Frictional Surface Area 71 cm2 (11 in2) Pressure Range

1.1 to 1.4 MPa (160 to 203 psi)

Weight Oil Capacity

165 kg (363.8 lb) Transmission (Total)

8.6 liter (9.1 qt)

Transmission (Drain and fill)

4.7 liter (5 qt)

Radiator

1 liter (1.1 qt)

Type of Oils Used

Kinematic Viscosity 5-7 cSt at 212°F (100℃ mm2/s） CALTEX：Torque Fluid 175; RPM torque fluid NO.5 ESSO:Torque Fluid 47 SHELL：Rotella 10w

Clean the oil filter（coarse strainer）

Every 1000 hours

Replace the oil filter（fine filter）

Every 250 hours

OVERVIEW The transmission is mounted with a torque converter and power gear-shift transmission case (see Figure 7).

The hydraulic transmission case and torque converter provides the following advantages: 1. The inching valve allows the truck to perform inching operations at both high and low engine speeds.

12

2. The hydraulic clutch is equipped with four pairs of brake shoes and steel plates that have been specially designed to be abrasion resistant.

3. The hydraulic clutch is mounted in the torque converter to improve the transmission power and efficiency.

4. A filter is located in the hydraulic circuit, to screen impurities from the fluid/oil and help keep the torque converter clean and functioning.

Hydraulic Transmission Case and Torque Converter

1.

2.

3.

4.

5.

6.

7.

8.

9.

GEAR SHAFT TAPERED ROLLER BEARING TORQUE CONVERTER HOUSING ASSEMBLY OIL PUMP ASSEMBLY COVER AND CONTROL VALVE ASSEMBLY CLUTCH ASSEMBLY BEARING PLATE HOUSING IDLER SHAFT

10. OUTPUT SHAFT 11. IDLER GEAR 12. OUTPUT GEAR 13. HYDRAULIC TOR-CON CONVERTER 14. INCH VALVE ASSEMBLY 15. DIFFERENTIAL ASSEMBLY 16. SPIRAL BEVEL GEAR 17. BEARING CAP

Figure 7. Hydraulic Transmission Device

13

Hydraulic Transmission Case and Torque Converter

TORQUE CONVERTER The torque converter is composed of three parts, a pump impeller, turbine, and guide pulley.

Pump impeller is driven by the input shaft. The fluid is sprayed onto the blades of turbine and along the pump impeller blades by centrifugal force. Torque is then provided to output shaft. The fluid exiting the turbine changes direction to the guide pulley. Reactive torque is then generated to push the guide pulley causing the output torque to be greater than the input torque. If the fluid flows into the blades of guide pulley in reverse direction, it causes the reactive torque to act in reverse. This causes the torque of output shaft to be less than the input shaft torque. To prevent this, the clutch mounted inside the guide pulley allows the guide pulley to rotate freely when reactive torque is reversed.

This method of torque conversion ensures a highefficient and steady operation.

The torque converter for the transmission is connected with the flywheel of engine through an elastic plate, it turns along with the rotation of the engine. Oil fills the torque converter. The drive gear is connected to the pump impeller by gear teeth, this controls the oil feed pump. The oil feed pump then supplies oil to the torque converted and the hydraulic shifting transmission case. The turbine is connected to the turbine shaft with splines. Power is transmitted to the power gear-shift transmission case through the turbine shaft.

14

1.

2.

3.

4.

5.

OIL DRAIN PLUG FLEX PLATE TURBINE GUIDE PULLEY THRUST BEARING

6. BALL BEARING 7. RETAINER RING 8. TURBO SHAFT 9. ONE-WAY CLUTCH 10. PUMP IMPELLER

Figure 8. Torque Converter

Hydraulic Transmission Case and Torque Converter

HYDRAULIC CLUTCH Wet multi-disk hydraulic clutch is mounted on the input shaft of hydraulic transmission case. It distributes oil pressure to the forward or reverse clutch through the control valve, this causes the forward and reverse gear shift. All the gears in transmission case are normallyengaged gears. Each clutch is composed of alternately assembled, four spacers (item 18, Figure 9), four brake shoes (item 19, Figure 9), and one piston (item 2, Figure 9). The internal and external surfaces of the piston are fitted with seal rings to ensure a proper seal.

1.

2.

3.

4.

5.

6.

7.

8.

END PLATE PISTON O-RING FORWARD GEAR RETURNING SPRING REVERSING GEAR BEARING SEAL RING (A)

In NEUTRAL position, the piston does not interact with the spacer and the brake shoe. While in gear, oil pressure controls the piston. The spacer compresses against the brake shoe, and an the adapter transmits power from torque converter to the driving gears (items 4 and 6, Figure 9).

The transmission of power from torque converter to hydraulic transmission case is as follows: Turbine → Input Shaft Assembly → Spacer → Brake Shoe → Forward Gear or Reversing Gear → Output Shaft

9. INPUT SHAFT ASSEMBLY 10. THRUST COLLAR (A) 11. NEEDLE BEARING 12. THRUST SHAFT COLLAR (B) 13. AXIS SNAP RING 14. SPRING SEAT 15. STEEL BALL 16. PLUG

17. SEAL RING (B) 18. SPACER 19. BRAKE SHOE 20. STOPPER 21. DISC PLATE 22. FORWARD OIL CIRCUIT 23. REVERSE OIL CIRCUIT

Figure 9. Forward/Reverse Clutch Pack

15

Hydraulic Transmission Case and Torque Converter

CONTROL VALVE, SAFETY VALVE, AND INCHING VALVE The Control Valve is mounted on the inner side of the transmission case cover (see Figure 10). The control valve includes three components: controlling slide valve, constant pressure valve, and adjusting valve.

• •

•

Controlling Slide Valve: Used to control forward and backward functions.

Constant Pressure Valve: Maintains the oil pressure of the hydraulic clutch to be within the range of 1.1-1.4 MPa (159.5-203.1 psi).

Adjusting Valve: It is located between inching valve and controlling slide valve. When controlling slide valve is fully open, this valve will start adjusting to reduce the impact of clutch during engagement.

The Overflow Valve: The overflow valve is connected to the transmission case and allows the oil pressure from the torque converter to maintain within its operating range 0.5-0.7 MPa (72.5-101.5 psi). See Figure 16 The Inching Valve The inching valve is installed on the left side of transmission case. The spool is connected to the linking rod of the inching pedal. This spool will move forward when inching pedal is pressed. The oil pressure of the hydraulic clutch will be reduced, causing the truck to move slowly. See Figure 11.

1. WOODRUFF KEY 2. O-RING SEAL

3. PIN

A. FORWARD B. NEURTRAL POSITION

C. REVERSE Figure 10. Control Valve

16

Hydraulic Transmission Case and Torque Converter

TRANSMISSION PUMP The transmission Pump is installed between the torque converter and the input shaft. It feeds oil to torque converter and hydraulic transmission case by actuating a pair of gears through pump impeller. See Figure 12.

1.

2.

3.

4.

5.

6.

7.

SCREW PLUG SCREW PLUG SNAP RING SPRING SCREW PLUG O-RING INCHING VALVE SHAFT

8. SPRING 9. SNAP RING 10. OIL SEAL 11. PAD 12. INCHING VALVE BODY 13. INCHING SLIDE VALVE

Figure 11. Inching Valve

TRANSMISSION CASE The transmission case houses the input shaft, output shaft, other internal components, and also functions as an oil tank. An oil filter is available on the side of the case to filter the oil that is drawn into the oil pump.

While the pipeline filter/oil filler cap are mounted in the upper part of the case cover.

1.

2.

3.

4.

DRIVING GEAR GUIDING GEAR SEAT DRIVEN GEAR PUMP SHELL Figure 12. Oil Feed Pump

17

Hydraulic Transmission Case and Torque Converter

TRANSMISSION HYDRAULIC SCHEMATIC After the engine is started, the oil feed pump draws out oil from the oil tank (the bottom of transmission case) through the oil filler. The oil then flows through the control valve in which the pressurized oil is divided into two parts. One part is fed to the hydraulic clutch, and the other part is fed to the torque converter.

The oil necessary for operation of hydraulic clutch flows into the constant pressure valve (the pressure of this valve should be adjusted to 1.1-1.4 MPa (159.5-203.1 psi)). The oil from the constant pressure valve then flows to inching valve, to the controlling slide valve. It is also directed from the inching valve into the impeller of torque converter through overflow valve (the pressure should be adjusted to 0.5-0.7 MPa (72.5-101.5 psi)). The oil coming out of the torque converter is cooled down

18

through transmission cooler. It then lubricates the hydraulic clutch and returns to oil tank. See Oil Inlet/ Outlet Connection Location When in neutral, the oil circuit from controlling slide valve to clutch is turned off. The constant pressure valve is turned on to make sure all the oil is transmitted to torque converter through the overflow valve. When controlling slide valve is in the forward or reverse position, the oil circuit from slide valve to the forward clutch or to reverse clutch is connected to make each clutch engage. When one clutch is engaged, the spacer and the brake shoes of the other clutch are separated and are lubricated by cooling oil.

When inching pedal operates the inching valve, part of or most of the oil flowing into clutch is drained to the oil tank through inching valve, of the oil to torque converter is the same as in neutral position.

Hydraulic Transmission Case and Torque Converter

1.

2.

3.

4.

5.

6.

7.

8.

9.

OVERFLOW PRESSURE BUFFER VALVE BUFFER VALVE MAJOR OIL PRESSURE MAJOR PRESSURE ADJUSTING VALVE OVERFLOW VALVE OVERFLOW PRESSURE IMPELLER GUIDE WHEEL TURBINE

10. TO LUBRICATING OIL CIRCUIT 11. ROUGH OIL FILTER 12. OIL PUMP 13. INCHING VALVE 14. CLUTCH PRESSURE REDUCTION FINISHES 15. CLUTCH PRESSURE REDUCTION STARTS 16. ELECTROMAGNETIC REVERSING VALVE 17. THROTTLE ORFICE 18. FINE OIL FILTER

Figure 13. Transmission Hydraulic Schematic

19

Hydraulic Transmission Case and Torque Converter

SPEED REDUCER AND SPEED DIFFERENTIAL Speed Reducer The speed reducer is located on the front of the transmission case (see Figure 14). This mechanism reduces the rotating speed of output shaft and increased the torque transmitted from the output shaft.

It sends this torque to the speed differential. The speed reducer is composed of a small spiral bevel gear on the output shaft, a large spiral bevel gear, and a small gear shaft. The large spiral bevel gear is mounted on the small gear shaft through spline while the two ends of small gear shaft are both supported with tapered roller bearing, and a gasket is used to adjust the clearance.

1.

2.

3.

4.

5.

6.

7.

8.

9.

SPEED REDUCER ASSEMBLY BEARING SEAT SHELL BEARING COVER BEARING GASKET TERMINAL BEVEL GEAR SHAFT DRIVING SPIRAL BEVEL GEAR RING SPIRAL BEVEL GEAR Figure 14. Speed Reducer

shell of speed differential is made into a type of left and right parts, with two half shaft gears and four planetary gears. The thrust washer is mounted between the shell of speed differential and gear and it is allowable for a clearance to be retained between respective gear pairs. The planetary gears are supported using gear shafts I and II, while gear shaft I is fastened onto the body of speed differential using cylindrical pink, and gear ring I is fixed onto the shell of speed differential using articulated bolts. See Figure 15.

A half shaft gear and half transmit power from the transmission through the differential and to the wheels.

1.

2.

3.

4.

5.

6.

7.

8.

GEAR RING BOLT BEARING COPPER PAD CROSS AXLE SPEED DIFFERENTIAL SHELL HALF-AXLE GEAR PLANETARY GEAR Figure 15. Speed Differential

TOWING THE LIFT TRUCK When the forklift truck with hydraulic transmission is damaged and must be towed by other vehicles.

Speed Differential

•

Remove the half shaft from the front wheel.

The speed differential is mounted on the front of the shell by a bearing seat and ball bearings on the two ends. The front is connected to the axle shell. The

•

Place the gear-shift lever in the NEUTRAL position.

20

Hydraulic Transmission Case and Torque Converter

OIL INLET/OUTLET CONNECTION LOCATION

Figure 16. Oil Inlet/Outlet Connection Location

21

Drive Axle

Drive Axle Type

Front Wheel Drive, Axle Body Fixed with Vehicle Chassis, and Fully Floating Type

Truck

2-2.5T

3-3.5T

Single Tire

Double Tire

Single Tire

Double Tire

Tire Model

7.00-12-12 PR

7.00-12-12 PR

28×9-15-14 PR

28×9-15-14 PR

Rim Size

5.00S-12

5.00S-12

7.00T-15

7.00T-15

Capacity

Tire Pressure

860 kPa (124.7 psi)

970 kPa (140.7 psi)

OVERVIEW The Drive axle is composed of the axle housing, wheel hub, half shaft, and brake. The axle housing is a cast structure. The tire is connected to the wheel hub by the wheel rim with stud bolts and nuts. The power is transmitted to half shaft through the speed differential, then to the front wheel, causing the wheel hub to rotate. Each wheel hub is mounted on axle housing by two tapered roller bearings, so the half shaft only receives the torque transmitted by wheel hut. The oil seal is fitted inside the wheel hub, to prevent entry of water and dust, or an oil leak.

The 2-2.5t the wheel rim for a single tire is a partial type, with the wide tire used for 3t and 3.5t. The 2-3.5t forklift trucks may be equipped with a double tire. See Figure 17 and Figure 18.

1.

2.

3.

4.

5.

WHEEL RIM WHEEL HUB BRAKE DEVICE AXLE HOUSING HALF SHAFT Figure 17. Single Wheel Drive Axle

22

Drive Axle

MAINTENANCE OF DRIVE AXLE To replace the drive axle wheel nut: 1.

Coat tapered roller bearing with lubricating grease.

2.

Tighten the lock nuts. Make sure that the rotating torque of the wheel hub is 9.8-29.4 N•m (7.2-21.7 lbf ft).

3.

Tighten the half shaft mounting nut. Torque to 96-111 N•m (70.8-81.9 lbf ft).

4.

Tighten the wheel mounting nut. Torque to 470-550 N•m (346.7-405.7 lbf ft).

5.

Tighten the brake drum mounting. Torque to 206-225 N•m (151.9-166.0 lbf ft).

Figure 18. Dual Wheel Drive Axle

23

Steering System

Steering System STEERING SYSTEM

Steering Cylinder

Type of Steering System

Rear Wheel Steering with Power Steering

Forklift Truck Capacity

2T, 2.5T, 3T, 3.5T

Cycloid Full Hydraulic Steering Gear

BZZ1-125BC-D

Cylinder Diameter

70 mm (2.8 in.)

Diameter of Piston Rod

50 mm (2 in.)

Stroke

99 mm (3.9 in.)

Diameter of Steering Wheel

300 mm (11.8 in.)

Overview The steering system is composed of a hydraulic steering gear, and steering cylinder.

Hydraulic Steering Gear Assembly The steering system is composed of a fully hydraulic steering gear and steering cylinder. See Figure 19 Item 2. The hydraulic steering gear transfers high pressure hydraulic fluid from the bypass valve to the steering cylinder. When engine is turned off, the pump cannot feed hydraulic fluid, and steering may be performed manually.

The steering column and steering wheel are designed to tilt 4.5º forward and backward, for operator comfort.

See Figure 19 Item 1.

1. STEERING WHEEL

2. STEERING GEAR

Figure 19. Hydraulic Steering Gear and Steering Wheel

24

Steering System

1. VALVE ELEMENT 2. SLEEVE 3. NEEDLE BEARING 4. SLEEVE 5. O-RING 6. VALVE BODY 7. O-RING 8. X-TYPE SEAL 9. FRONT CAP 10. O-RING 11. SPRING WASHER 12. HEX SOCKET SCREW 20-30 N•m (14.8-22.1 psi) 13. PIN 14. VALVE DRUM 15. WASHER

16. SPRING SHIM 17. JOINT SHAFT 18. MIDDLE PLATE 19. ROTOR 20. STATOR 21. O-RING 22. SLIP RING 23. LIMIT RING 24. REAR CAP 25. WASHER 26. LIMIT BOLT 35-40 N•m (25.8-29.5 psi) 27. HEX FLANGED SCREW 35-40 N•m (25.8-29.5 psi) 28. THREAD BUSHING 29. STEEL BALLS

Figure 20. Hydraulic Steering Gear

25

Steering System

Steering Cylinder The steering cylinder is a double acting cylinder. The two ends of piston rod are connected with a steering knuckle by connecting rod. Pressurized oil from the

1.

2.

3.

4.

5.

6.

7.

8.

CYLINDER CASING CIRCLIP O-RING AXIAL SEAL RING FLAP O-RING SEAL CYLINDER CAP DUST RING

fully hydraulic steering gear enables the piston rod to move left or right through steering cylinder, thus to achieve proper steering.

9. RETAINER 10. PISTON ROD 11. SUPPORT RING 12. O-RING SEAL 13. STEEL BALL 14. PISTON 15. O-RING SEAL 16. SUPPORT RING Figure 21. Steering Cylinder

26

Steering System

Inspection of Reassembled Steering System 1.

Turn the steering wheel to the left and right, to confirm both sides will turn to equally.

2.

Inspect hydraulic oil lines and confirm they are connected in the right direction and properly routed.

3.

Use a jack to lift the rear wheels. Slowly turn the steering wheel to the left and right. Repeat for several times, to remove any air from the fluid line and cylinder.

Troubleshoot Steering System Problem Steering Wheel Not Turning

Hard Steering

Forklift Truck Swinging walk

Abnormal Noise

Fluid Leak

Cause

Solution

Oil pump damaged or malfunctioning

Replace pump

Priority spool blocked or damaged

Clean or replace

Rubber hose joint damaged or fluid line blocked

Clean or replace

Steering relief valve pressure too low

Adjust Steering relief valve

Air present in oil circuit

Remove air

Reset of steering gear out of operation, and positioning leaf spring broken

Replace leaf spring

Excessive internal leak of steering cylinder

Inspect sealing of piston

Excessive oil flow

Adjust Steering relief valve

Warn or damaged steering components

Check physical components

Fluid tank level low

Add hydraulic fluid

Suction pipe or oil filter blocked

Clean or replace suction pipe or filter

Steering cylinder guide sleeve damaged or hoses or Replace joint damaged

27

Steering and Drive Axle Information

Steering and Drive Axle Information STEERING AXLE Tonnage

2-3.5t

Type of Axle body

Supported with Central Supporting Shaft

Steering angle King pin

Inner Side Wheel

78º

Outer Side Wheel

54º

Center to Center of Kingpins

810mm (31.89 in)

Side Inclination Angle

0º

Wheel Camber Angle

1º Wheel

Tonnage Tire Rim Inflation Pressure Total Weight

2-2.5t

3-3.5t

Drive

7.00-12-12 PR

28×9-15-14 PR

Steer

6.00-9-10 PR

6.50-10-10 PR

Drive

5.00S-12

7.00T-15

Steer

4.00E-09

5.00F-10

Drive

860KPa (124.7 psi)

970KPa (140.7 psi)

Steer

860KPa (124.7 psi)

790KPa (114.6 psi)

Around 115kg (253.5 lbs.)

Overview The steering bridge is an open welded structure with box cross-section (see Figure 22). It is composed of the steering bridge body, the steering cylinder, the connecting rod and the steering wheel. The steering trapezoid adopts a crank slider mechanism. Before and after the steering axle by pry to the frame at the back of the pin shaft through the bearing bolt tail

28

Around 140kg (308.6 lbs.) frame, swing bridge fitness around the pin axis, around the steering axle were about to have a steering knuckle, wheel hub with two tapered roller bearings after loaded on the steering shaft, wheel by pry to the hub, rim inside of the bearing is equipped with oil seal, keep the grease in the cavity between the wheel and steering knuckle.

Steering and Drive Axle Information

1. LEFT UNIVERSAL JOINT 2. STEERING AXLE 3. NUT M12 4. NUT M12X40 5. WASHER 14 6. WASHER 14 7. BOLT M14X45 8. KING PIN 9. CYLINDRICAL PIN 10X20 10. BUSHING 11. BEARING 198908K 12. RIGHT UNIVERSAL JOINT 13. HEX NUT M12X30 14. COTTER PIN 6.3X50 15. OIL SEAL 16. WHEEL BOLT 17. WHEEL 18. WHEEL NUT 19. WHEEL CAP

20. NUT M20X2 21. WASHER 30 22. TAPERED ROLLER BEARING 23. BEARING 30211 24. GREASE NIPPLE Z1/8 25. OIL SEAL 26. NEEDLE BEARING 27. O-RING 28. ADJUSTING SHIM 29. LINK PIN 30. LINK ROD 31. RETAINING PLATE 32. WASHER 8 33. BOLT M8X16 34. KNUCKLE BEARING 35. NIPPLE M6 36. BUSHING 37. STEERING CYLINDER Figure 22. Steering Axle

29

Steering and Drive Axle Information

Steering Knuckle and Steering King Pin Steering knuckle is mounted between the upper and lower shaft sleeves on the two ends of steering axle body using steering knuckle king pin, thrust bearing, and gasket. The middle part of king pin is locked on steering knuckle using grub screw, while the two ends of king pin are supported by needle roller bearings pressed on the axle body. Oil seals are mounted on the two ends of needle roller bearings, and oil cup is fitted on the king pin.

7.

Lock the slot nut using cotter pin, when specified rotating torque is reached.

Steering Wheel Bearing Pre-load Information 1.

Grease the hub, internal and external bearings and the inner cavity of the hub cap and lip of oil seal. See Figure 23.

2.

Install the bearing outer ring onto the wheel hub, and mount the wheel hub onto the shaft of steering knuckle.

3.

Mount the flat washer and tighten the slot nut.

Torque to 206-235 N•m (151.9-173.3 lbf ft).

4.

Loosen the slot nut and then tighten the nut.

Torque to 9.8 N•m (7.2 lbf ft).

5.

Tap the wheel hub gently using a hammer.

Manually turn the wheel hub 3-4 times to ensure a steady rotation. Torque to 2.9-7.8 N•m (2.1-5.8 lbf ft).

6.

30

When rotating torque is higher than the specified value, loosen nut by 1/6 turn, then check torque again.

1. SLOT NUT 2. GREASING LOCATION Figure 23. Adjustment for Pre-loading

Brake System

Brake System Type

Front Twin Wheel Brake, Internal Expansion, Hydraulic

Pedal Lever Ratio

5.66

Master Cylinder Diameter

19.05 mm (0.75 in.)

Wheel Brake

2-2.5T

3-3.5T

Type

Dual Servo Type with Parking Brake

Wheel Cylinder Diameter

28.6 mm (1.1 in.)

Size of Brake Shoe (L×W×T)

324×60×7 mm (12.8×2.4×0.28 in.)

348×76×8 mm (13.7×2.99×0.31 in.)

Area of Brake Shoe

194.4 cm ×4

264 cm2×4

Inner Diameter of Brake Drum

310 mm (12.2 in.)

314 mm (12.4 in.)

Parking Brake

2

Front Twin Wheel Brake, Internal Expansion, and Hydraulic Type

OVERVIEW Brake system is in a front double-wheel brake type, and it is composed of brake master cylinder, Dry Brakes (Drum and Shoes), and brake pedal.

BRAKE MASTER CYLINDER The brake master cylinder contains a valve seat, oneway valve, return spring, primary cup, piston, and secondary cup. It is held together using a thrust washer and snap ring. The external part is protected through a rubber dust cap. The master cylinder piston moves with a push rod that is operated by the brake pedal. When brake pedal is activated, the push rod pushes the piston forward, and the brake fluid in the cylinder body flows back to oil tank through return oil port, until the primary packing cup blocks the return oil hole. After primary packing cup blocked the return oil port, the brake fluid in front cavity of master cylinder is

compressed and opens the one-way valve. This allows oil to flow to the wheel cylinder through the bypass pipeline. The pistons of the wheel cylinders extend outwards. This causes friction plate of brake shoes and the brake drum to contact each other, allowing the forklift truck to deceleration and brake. The rear cavity of piston is supplied with the brake fluid from return oil port and oil inlet port. When brake pedal is released, the piston is retracted by the return spring. Brake cylinders are likewise compressed by return spring of brake shoes, causing the brake fluid to return to the master cylinder (the front cavity of piston) through a one-way valve. The piston returns, and the brake fluid in master cylinder flows back to oil tank through return oil port. The pressure of the one-way valve adjusts to to the remaining pressure in brake cylinders. This causes the secondary packing cup of wheel cylinder to be correctly placed to prevent oil leaks, and to eliminate air in the brake system.

31

Brake System

1. TO OIL RESERVOIR 2. TO WHEEL SPEED REDUCER

3. PRIMARY PACKING CUP 4. SECONDARY PACKING CUP Figure 24. Brake Master Cylinder

WHEEL BRAKE The wheel brake is a internal expansion, hydraulic type, composed of brake shoes, spring, wheel cylinder, adjuster, and bottom plate. The two brake shoes are mounted on the two ends of the front axle. One end of brake shoe is connected with support pin, while the

32

other end is connected to the brake adjuster, and presses onto the bottom plate by spring and pull rod.

The brake is mounted on primary brake shoe, while adjustment pull rod for automatic clearance adjuster is on secondary brake shoe. See Figure 25 and Figure 26.

Brake System

Figure 25. 2-2.5T Wheel Brakes

33

Brake System Legend for Figure 25.

1. BOTTOM PLATE 2. ADJUSTING SLEEVE 3. BRAKE SHOE 4. ELASTIC GASKET 5. PARK BRAKE PULL ROD 6. RETURN SPRING 7. SHIM 8. MANDREL 9. PULL SPRING 10. PART BRAKE PUSH ROD 11. COMPRESSED SPRING 12. ADJUSTING LEVERAGE 13. SPRING SEAT

34

14. SPRING 15. SPRING CAP 16. SPRING 17. SPRING SEAT 18. SPRING PULL ROD 19. SUPPORT PIN 20. SHIM 21. RUBBER PLUG 22. BRAKE CABLE 23. BOLT M8X16 24. WASHER 8 25. BRAKE CYLINDER 26. COVER 27. PISTON ROD

28. PISTON 29. BRAKE CYLINDER CUP 30. BRAKE CYLINDER SPRING 31. OIL PLUG 32. DEFLATION SCREW 33. DEFLATION SCREW COVER 34. DUST CAP 35. RIVET 36. CUSHION 37. SUPPORT PIN 38. CLEARANCE-ADJUSTING BOLT 39. WASHER 10 40. CLEARANCE-ADJUSTING ROD

Brake System

1. BRAKE CYLINDER 2. CLUTCH DISCS WITH FRICTION PLATE ASSEMBLY 3. BOTTOM PLATE 4. BRAKE ADJUSTER 5. SPRING CABLE 6. BRAKE SHOES WITH FRICTION PLATE 7. SPRING PULL ROD 8. SPRING SEAT 9. COMPRESSED SPRING

10. RUBBER PLUG 11. PULL SPRING 12. GUIDE PANEL 13. GUIDE PLATE 14. RETURN SPRING (REAR) 15. TORSION SPRING 16. PAWL 17. PIN 18. LEFT BRAKE PUSH ROD

19. SPRING 20. PARK BRAKE PULL ROD 21. PIN 22. ELASTIC GASKET 23. ROD-PIN RETAINER 24. BRAKE CABLE 25. WASHER 26. BOLT 27. RETURN SPRING

Figure 26. 3-3.5T Wheel Brake

35

Brake System The brake action in forward movement is as follows: (see Figure 27). Through operating brake wheel cylinder, the Brake shoes are effected by two forces of equal size but reverse directions, respectively, for Brake shoes and brake drum to get into contact with each other, while the primary Brake shoes is pressed onto the adjuster with support of friction force between Brake shoes and brake drum, thereby for brake adjuster to generate a larger force used to operate the wheel cylinder to push the secondary Brake shoes, and to force the upper end of secondary Brake shoes to bear down on the support pin, thus to get a relatively large brake force. In another connection, the reversing brake action is performed in reverse direction, but the brake force is the same as that during forward movement.

1.

2.

3.

4.

POSITIONING PIN BRAKE DIRECTION FORCE DRIVING BRAKE SHOE Figure 28. Brake Actions during Reversing Process

AUTOMATIC BRAKE ADJUSTER

1.

2.

3.

4.

BRAKE DIRECTION POSITIONING PIN FORCE DRIVING BRAKE SHOE

Figure 27. Brake Actions during Forward Running Process

36

The automatic brake adjuster is able to automatically maintain the clearance between brake shoes and brake drum between 0.4-0.45 mm (0.016-0.018 in.) for 2-2.5 ton or 0.25-0.4 mm (0.01-0.016 in.) for 3-3.5 ton.

However this adjuster only acts during reversing brake. During reverse movement, the brake shoes will disengage once the brake pedal is activated, thereby, the secondary and the primarily Brake shoes will begin to get into contact with brake drum for rotation together, until the upper end of primarily Brake shoes begins to get into contact with support pin.

When the secondary brake shoes is released from the support pin, the A part of adjusting level Figure 25).

When the brake pedal is released, point B of the rod is lowered. As the clearance between the friction plate and the brake drum is increased, the distance of point B increases also. When the distance is more than 0.4mm, point B will contact the adjuster bolt (item 38, Figure 25) and the clearance will decrease.

Brake System

MANUAL BRAKE

ADJUSTMENT OF BRAKE PEDAL

The manual brake uses a pull handle. With the foot brake, it employs an automatic power brake that stops the front wheels. Only when the truck has been parked, can the manual parking brake be used.

1.

Before adjusting the parking brake, test to confirm the drive axle braking system functions properly: 1.

Adjust the lock nut (item 5, Figure 29) so the length is equal to 68 mm (2.7 in.). Tighten the lock nut.

2.

Turn the nut (item 7, Figure 29) to adjust the parking brake’s pulling force to 147-196 N•m (108.4-144.6 lbf ft).

3.

After the manual brake lever is correctly adjusted, release the lever to release the brake.

4.

Ensure that the parking brake is functioning properly.

Adjust the limit bolts to the pedal location shown in Figure 30. Confirm the distance between the front floor and the brake pedal is 113 mm (4.4 in.) and the pedal stroke is 20 mm (0.8 in.). Tighten the limit bolts.

NOTE: Coat appropriate amount of lithium base grease onto the guide rail (item 6, Figure 29) and apply regularly.

1. OIL TANK 2. LIMIT BOLT 3. PEDAL

4. INCHING VALVE 5. BRAKE MASTER PUMP

Figure 30. Adjustment of Brake Pedal

1. BRAKE CABLE 2. BRAKING ROPE 3. DISPLAY BRACKET 4. PARKING BRAKE LEVER

5. LOCK NUT 6. GUIDE RAIL 7. NUT

Figure 29. Parking Brake

37

Brake System

MAINTENANCE This section covers brake disassembly, reassembly, and adjustment. The following procedures describe

Disassemble, Wheel Brake STEP 1.

Remove the spring of the secondary brake shoes, and the adjusting lever, top lever, and the top lever return spring.

STEP 2.

Remove the return springs for the two brake shoes.

STEP 3.

Remove the other three fixed springs.

38

steps for servicing a 2-2.5T brake. Brakes for 3-3.5T are similar.

Brake System STEP 4.

Detach the primary brake shoes and the secondary brake shoes, and remove the spring for adjuster.

STEP 5.

Remove the brake fluid line from the wheel cylinder. Remove the mounting bolts for the wheel cylinder, and separate the wheel cylinder from the bottom plate.

STEP 6.

Remove the E-shaped retainer ring that fastens the brake cable onto the bottom plate, then remove the mounting bolts on bottom plate, and detach the bottom plate from the axle.

39

Brake System STEP 7.

Remove the shield for the wheel cylinder, remove all the parts from inside the cylinder.

Examination of Wheel Brake

6.

Examine all the parts for ware or damage. Replace parts as necessary.

1.

Examine the inner surface of the wheel cylinder body and the surface of piston column for rust.

Measure the clearance between the piston and cylinder body. Replace if necessary.

Specified Value: 0.065-0.150 mm (0.003-0.006 in.) (2-3.5T truck only).

2.

3.

Check if the rubber cup is damaged or distorted.

Measure the diameter of the rubber cup to confirm specified value of Φ30.1-0.2 (2-3.5T).

The standard value for interference of rubber cup is Φ1.52, and the minimum value is Φ0.42 (2-3.5T).

Check the free lengths of the wheel cylinder spring. Replace if necessary.

Specified Value: 60 mm (2.4 in.) for 2-2.5T and 58 mm (2.3 in.) for 3-3.5T.

4.

Check the thickness of the brake shoes. Replace if excessively worn.

Specified Value: 4.5-7.2 mm (0.18-0.28 in.) for 2-2.5T and 5.0-8.8 mm (0.20-0.35 in.) for 3-3.5T.

5.

Check the diameter of the inner surface of the brake drum to confirm specified value. Replace or restore if excessively worn.

Specified Value: 310-312 mm (12.20-12.28 in.) for 2-2.5T and 314-316 mm (12.36-12.44 in.) for 3-3.5T.

40

Measure the free length and installation load of return spring for brake shoes. See Figure 31.

Forklift Truck Tonnage

2-2.5T

3-3.5T

Free Length

106 mm (4.17 in.)

115.1 mm (4.53 in.)

Installed Length

116 mm (4.57 in.)

122 mm (4.80 in.)

Maximum working

246 N (55.3 lb)

225 N (50.58 lb)

Figure 31. Load return spring for brake shoe 7.

Measure the free length and installation load of return spring for top rod. See Figure 32.

Brake System

Forklift Truck Tonnage

2-3.5T

Free Length

124.5 mm (4.90 in.)

Installation Length

130 mm (5.12 in.)

Installation Load

246 N (55.3 lb)

Figure 32. Load return spring for top rod 8.

Measure the free length and installation load of adjuster spring. See Figure 33.

Forklift Truck Tonnage

2-2.5T

3-3.5T 121 mm (4.76 in.)

Free Length

86 mm (3.39 in.)

Installation Length

137 mm 97 mm (3.82 in.)

(5.39 in.)

Figure 34. Ratchet spring 10. Check the adjusting spring for damage and confirm the adjusting lever is functioning properly.

Replace if necessary.

Assemble, Wheel Brake 1.

Coat the wheel cylinder rubber cup and piston with brake fluid.

2.

Assemble the spring, rubber cup, piston, and shield.

3.

Mount the wheel cylinder on bottom plate.

NOTE: Confirm that all parts are in correct position during installation and bolts are torque to 14.7-19.6 N•m (10.84-14.46 lbf) for 2-2.5T and 17.6-26.5 N•m (12.98-19.55 lbf ft) for 3-3.5T. 4.

Mount the bottom plate onto the front axle. Torque to:120-140 N•m (88.50-103.26 lbf).

5.

Add lubricating grease at items 1, 2, 4 and 5 on Figure 35. Be careful not to allow this grease to adhere to brake shoes.

Installation Load 152 N (34.17 lb) 71.5 N (16.1 lb) Figure 33. Adjusting spring 9.

Measure free length and installation load of ratchet spring (see Figure 34). Installation Load: 14.7N (3-3.5t)

41

Brake System

SUPPORT FACE OF BOTTOM PLATE SUPPORT PIN OF LEVER L H BRAKE SUPPORT PIN ADJUSTER THREAD AND OTHER ROTATING PARTS 5. CONTACT FACE OF BRAKE SHOE AND WASHER CUP

8.

Mount the compressed spring onto the hand brake push rod. Install the push rod onto the brake shoes.

9.

Mount the guide plate of brake shoes onto the support pin. Install the return spring of brake shoes.

1.

2.

3.

4.

Figure 35. For 2-3.5T Forklift Truck 6.

Mount the brake cable assembly onto the bottom plate using E-shaped retainer ring.

7.

Mount the brake shoes onto the bottom plate using the fixing spring. Install the washer, cup and the adjusting lever. Mount the bottom part of the secondary brakes shoe with fixing spring. Make sure that the pressure seat is fitted in the holes of brake shoes and adjusting lever.

10. Install adjuster, adjuster spring, top rod, and return spring for top rod.

Check the following: •

• •

• •

42

Adjuster thread direction and installation direction.

- For 2-2.5T trucks, right-hand thread is used for left brake, while the left-hand thread is used for right brake.

- For 3-3.5T trucks, left-hand thread is used for left brake, while right-hand thread is used for right brake.

Adjuster spring direction The tooth part of adjuster must not contact the spring.

Top rod return spring direction. The spring hook must be installed on the opposite side of the top rod at the end of the support pin.

Top rod and top rod return spring shall be fixed inside the slot of support pin.

Make sure that the lower end of adjusting lever contacts the tooth of the adjuster.

Brake System

Operating Test Automatic Clearance Regulator 1.

Allow the diameter of brake shoes to approach the installation size. Pull the adjusting lever to rotate. When the adjusting lever is released, it returns to its original place. The adjuster gear will not rotate.

NOTE: Even when hand brake is released, the adjuster will still function properly after being assembled.

2.

11. Connect the brake fluid line onto the wheel cylinder.

12. Measure the inner diameter of the brake drum.

Adjust the differences between the inner diameter of brake drum and the friction plate of brake shoe to: •

0.8-0.9 mm (0.031-0.035 in.) for 2-2.5T trucks.

•

0.5-0.8 mm (0.019-0.031 in.) for 3-3.5T trucks.

If the adjuster does not return to original position, inspect these items. a.

Mount the adjusting lever, the top rod, the top rod spring, and the washer cup.

b.

Examine whether or not the position of the adjusting lever and adjusting gear is correct (see Figure 36.) Replace the parts if necessary. Check if lever and gear are in contact with each other.

43

Brake System

1. TURN BRAKE ADJUSTER Figure 36. Brake Adjuster 3.

44

Check the return spring of top rod and the adjuster spring for damage. Confirm no wear or damage.

4.

Make sure the adjuster gear rotates. Confirm no wear or damage.

Brake System

Troubleshoot Wheel Brake Problem

Brake Spongy

Brake Noise

Cause Fluid leak in brake system

Repair

Clearance of brake shoes not properly adjusted

Adjust adjuster gear

Brake too hot

Check if skidding exists

Poor contact between brake drum and brake shoe

Adjust brake adjuster

Contamination on brake shoe

Repair or replace brake shoe

Contamination in brake fluid

Inspect brake fluid

Brake pedal (inching valve) improperly adjusted

Adjust brake pedal

Surface of brake shoes hardened or dirty

Repair or replace brake shoes

Bottom plate distorted or bolt loosened

Repair or replace plate

Brake shoes distorted or installation incorrect

Repair or replace brake shoes

Brake shoes worn

Repair or replace brake shoes

Loose wheel bearing

Repair or replace

Brake fluid on brake shoes

Repair or replace brake shoe

Brake Drum or Brake Shoe Clearance of brake shoes not properly adjusted surfaces damaged or Wheel cylinder failure distorted Brake shoe return spring damaged

Braking Pressure Low

Solution

Adjust brake adjuster Repair or replace Replace

Brake drum failure

Repair or replace brake drum

Fluid leak with brake system

Repair leak

Clearance of brake shoes not properly adjusted

Adjust brake adjuster

Air in brake system

Bleed air

Adjustment of brake pedal incorrect

Readjust

45

Hydraulic System

Hydraulic System NOTE: If the forklift truck is kept without operating for a long time, it is required to lift the mast cylinder 2-3 Forklift Truck Tonnage

times at least every 10 days for lubrication maintenance.

H2.0UT

Equipped Engine Gear Type

Driving

Gear Type

Gear Type

Engine driven 72 liter/min (19 gal/min)

72 liter/min (19 gal/min)

82 liter/min (21.7 gal/min)

No load flow

78 liter/min (20.6 gal/min)

78 liter/min (20.6 gal/min)

78 liter/min (20.6 gal/min)

88 liter/min (23.2 gal/min)

Model

MFT04

MFT04

MFT04

MFT04

Double Spool Valve, with Overflow Valve, Bypass Valve, and Inclined Auto-locking Valve, pilot valve load feedback 18 MPa (2610.68 psi)

18 MPa (2610.68 psi)

18 MPa (2610.68 psi)

18 MPa (2610.68 psi)

Pressure

11 MPa (1595.42 psi)

11 MPa (1595.42 psi)

11 MPa (1595.42 psi)

11 MPa (1595.42 psi)

Flow Rate

12 liter/min (3.2 gal/min)

12 liter/min (3.2 gal/min)

12 liter/min (3.2 gal/min)

12 liter/min (3.2 gal/min)

Adjusting Pressure

Type Cylinder Inner Diameter

Single Act Piston Type, with Shutoff Valve, one-way valve and lower buffer Φ50 mm (2.0 in.)

Φ50 mm (2.0 in.)

Φ56 mm (2.2 in.)

Φ63 mm (2.5 in.)

Stroke

(2nd-grade Standard Mast at 3m Lifting Height) 1495mm (Varying along with Type of Mast and Lifting Height)

Type

Double Acting Double Acting Double Acting Double Acting Cylinder Cylinder Cylinder Cylinder

Cylinder Inner Diameter

Φ70 mm (2.8 in.)

Φ70 mm (2.8 in.)

Φ80 mm (3.1 in.)

Φ80 mm (3.1 in.)

Piston Rod Outer Diameter

Φ32 mm (1.3 in.)

Φ32 mm (1.3 in.)

Φ35 mm (1.4 in.)

Φ35 mm (1.4 in.)

Stroke

122 mm (4.8 in.)

122 mm (4.8 in.)

141 mm (5.6 in.)

141 mm (5.6 in.)

Tilt Cylinder

46

Gear Type

72 liter/min (19 gal/min)

Bypass Valve

Lift Cylinder

H3.5UT

Full load flow

Type Multi-way Valve

H3.0UT

PSI 4G64 2.4L

Type

Main Pump

H2.5UT

Hydraulic System

OVERVIEW The hydraulic system is composed of a steering control unit, a multi-way valve, lift cylinders, tilt cylinders, and Hydraulic hoses and or Hydraulic Tubes, The power-take-off (PTO) of the engine drives the steering control unit directly.

Because the pump housing and pump cover are made from aluminum, they are light and sturdy. The active gear and the passive gear each have two shafts that are individually installed on the pump housing bearings. These bearings are made of special material, to bear the radial load of the gear and also serve as the baffle seats for the gear ends.

On the drive shaft side, a fluid seal is installed on the pump housing. A seal between the pump housing and the cover rely on a specially-shaped seal ring.

STEERING CONTROL UNIT The steering control unit is a gear pump consisting of a pump housing, pump cover, one pair of gears, a bearing, and seal rings. The pump employs a loadbalancing bearing and a special lubrication method which minimizes the gap at the gear ends.

Because the pump housing and pump cover are made from aluminum, they are light and sturdy. The active gear and the passive gear each have two shafts that are individually installed on the pump housing bearings. These bearings are made of special material, to bear the radial load of the gear and also serve as the baffle seats for the gear ends.

On the drive shaft side, a fluid seal is installed on the pump housing. A seal between the pump housing and the cover rely on a specially-shaped seal ring.

MULTI-WAY VALVE AND PRIORITY SPOOL The 4-disk multi-way valve consists of a six-plate valve body, four spool valves, one relief valve, and one priority spool. The six-plate valve body is assembled using three stub bolts and nuts. The tilt spool valves are fitted with a tilt auto-locking valve.

1. SAFETY OVERFLOW VALVE 2. LIFTING SPOOL VALVE 3. TILT SPOOL VALVE 4. AUX. SPOOL VALVE

5. PORT (OIL OUTLET) 6. BYPASS VALVE (CONNECTED WITH STEERING GEAR) 7. PORT (OIL INLET)

Figure 37. Multi-way Valve

47

Hydraulic System

Operation of Spool Valve The Tilt Spool Valve is described below. All other spool valves operate, and are repaired in a similar fashion.

Neutral Position In the NEUTRAL position, the high-pressure fluid is drained from the pump and returns to the fluid tank.

See Figure 38.

1. FLUID FROM TILT CYLINDER INTERFACE B 2. FLUID TO TILT CYLINDER INTERFACE A 3. RETURNING TO FLUID TANK Figure 39. Push-in Spool Valve

Spool Valve (Pulled out): When neutral position is closed, the hydraulic oil from the inlet port opens the one-way valve and flows to the cylinder interface A, (item 2, Figure 40) while the oil from cylinder interface B (item 1, Figure 40) flows to the tank through low-pressure channel. A return spring returns the valve to NEUTRAL position.

Figure 38. Spool Valve Neutral

Spool Valve (Pushed In): When the valve is pushed in, the middle channel is closed while the fluid from the inlet port opens the oneway valve. The fluid flows to the interface B of the cylinder (item 1, Figure 39), while the fluid from cylinder interface A (item 2, Figure 39) flows to the tank through low-pressure channel (item 3, Figure 39).

A return spring returns the valve to NEUTRAL position.

1. FLUID TO CYLINDER INTERFACE B 2. FLUID FROM TILT CYLINDER INTERFACE A 3. RETURNING TO FLUID TANK Figure 40. Pull-out Spool Valve

48

Hydraulic System

Primary Relief Valve and Priority Spool Reference Figure 41 The primary relief valve is composed of the two parts, a main valve and pilot valve. When multi-way valve is reversed, the high-pressure oils in cavity (P) and working mechanisms (such as lift cylinder and tilt cylinder) are connected, the pressurized oil acts on the pilot valve, through the fixed throttle holes. When system pressure is larger than the system regulated pressure, the pilot valve opens, The valve core of the entire main valve (A) moves rightwards, for the pressurized oil to be directly connected with lowpressure channel (G), for cavity for the pressure in cavity P to lower, in order to ensure the stability of system pressure. Adjusting screw H on the primary relief valve will increase or decrease the system pressure.

first and then actuates, to divert oil to provide hydraulic oil to the hydraulic valve for Mast functions. When the steering wheel is rotated, the oil cavity (M) is connected with high-pressure oil circuit. When system pressure is greater than spring pressure, the valve core (N) moves right, and pressure oil is connected with low-pressure oil circuit through cavity (T), for the pressure in cavity (M) to lower, in order to ensure the stability for the pressure of steering system. Adjusting screw K may be used to adjust the stable pressure value of the system.

By changing the flow rate and pressure, the slide valve L moves to the left and right to change the opening of (R) and (S), to ensure the automatic balance of the flow rate of the deworking chamber (Q) and PF orifice and the full hydraulic steering gear, and the flow is divided stable in proportion

The priority spool is in a spool and spring set up. It is used to divert oil to the Steering Control Unit (SCU)

1. ONE WAY VALVE 2. CONNECTING ORBITROL 3. STEERING OVERFLOW VALVE

4. OIL RETURN 5. MAIN RELIEF VALVE

Figure 41. Primary Relief Valve and Priority Spool

49

Hydraulic System

Inclined Auto-Lock Valve The tilt spool valve is fitted with an auto-lock valve to prevent vibration caused by back pressure inside the tilt cylinder. It is designed to keep the mast of the lift truck from "drifting" while a load is raised. The inclined

1. CONNECTING TILT CYLINDER INTERFACE B

spool valve can still be operated to tilt backward after the engine is turned off. However, when this tilt autolock valve is used, a forward tilt can not be performed when the engine is turned off. See Figure 42 for tilt auto-lock valve structure.

2. CONNECTING TILT CYLINDER INTERFACE A

Figure 42. Tilt Auto-lock Valve The interfaces “2” and “1” of valve body connect separately with front and rear housing of the tilt cylinder piston. When spool valve is pulled out, (control lever pulled back) the high-pressure fluid enters into interface “2” (item 2, Figure 42), while the oil in the rear cavity returns to the tank. In this case, the mast is tilted backward.

When the spool valve is pushed in (control lever is pushed forward), high pressure oil enters connector “1”, (item 1, Figure 42) by high pressure oil, and the lock valve in spool works to make “2” connect with low pressure. When engine is off or stopped, there is no high-pressure oil for auto-lock inside the spool valve to act. In this case the interface “2” cannot be connected with low pressure, and the mast will not tip forward and there is no back pressure in tilt cylinder.

50

HYDRAULIC SYSTEM MAIN OIL CIRCUIT The high-pressure oil from the steering control unit is routed to the multi-way pump, and is split into two parts by the priority spool within the multi-way valve.

High pressure oil is divided to either go to the hydraulic control valve or the SCU (Steering Control Unit). When the lift or tilt spool valves are at the neutral position, the high-pressure oil returns to tank. When lift spool valve is pulled, the high-pressure oil passes through the velocity fuse, and then pushes the piston of the lifting cylinder up. When lift spool valve is pushed, the lower part of lift cylinder piston is connected with low pressure, allowing the piston to drop, depending on mast weight and cargo weight. The oil flowing out from lift cylinder then passes through the velocity fuse for the lowering speed to be controlled. When the tilt spool valve is operated, the high-pressure oil may flow into the front cavity of tilt cylinder, while the other side is connected with low pressure. This causes the mast to tilt backward or forward.

Hydraulic System

Figure 43. Oil Circuit of Hydraulic System

51

Hydraulic System

Figure 44. Oil Circuit of Hydraulic System (OPS)

52

Hydraulic System

LIFT CYLINDER Two single-acting lift cylinders are attached on the back of the outer mast channel, and the bottom part of cylinder is attached to the outer mast channel using pins and bolts. The top part of the cylinder (piston rod) is connected to the cross member of the outer mast channel. The piston strokes must be adjusted to be consistent, for the two cylinders to lift simultaneously.

The lift cylinder is composed of cylinder body, piston, piston rod, cylinder cover, cylinder bottom and sealing parts. One port is located in the lower part of cylinder body. A return pipe is mounted in the upper part of cylinder body for a small amount of leaked fluid to return to the tank. The piston is fastened onto the piston rod using a nut and cotter pin, and one seal

1.

2.

3.

4.

5.

6.

7.

BEAM WIPER SHAFT SEAL CYLINDER COVER O-RING CYLINDER ROD CYLINDER BODY

ring, retainer ring and wear ring are fitted on the outer surface of the piston (see Figure 45). The highpressure fluid moves the piston along the cylinder body. A shaft sleeve and dust ring are mounted in the inner hold of cylinder cover, to support the piston rod, while resisting dust.

When the lift is commanded, the high-pressure fluid enters through the bottom part of lift cylinder, pushing up the piston attached to the mast and raising the inner mast along with the lift chain. When lower is commanded, the fluid under the piston will flow out under the weight of the forks and cargo, and the inner mast will be lowered. The oil drained out from lift cylinder is controlled by velocity fuse, and returns to tank through multi-way valve.

8. O-RING 9. PISTON 10. SUPPORT RING 11. RETAINER RING 12. SEAL RING 13. RETAINER RING 14. LOCATER PIN 15. VELOCITY FUSE

16. VALVE SLEEVE 17. CHECK VALVE 18. HOIST CHAIN 19. RETAINER RING 20. ROLLER SPROCKET 21. SHIMS 22. BOLT

Figure 45. Lifting Cylinder

53

Hydraulic System There is one velocity fuse on the bottom of the lift cylinder (see Figure 46). It is designed to prevent load from sudden drop, in the event that a hose carrying hydraulic oil should suddenly fail. The fluid from lift cylinder passes through the velocity fuse, and the oil holes around the spool valve generates pressure

A. WHEN NORMAL

difference. When this pressure difference is smaller than the spring force, the spool valve will not act. If the high-pressure hose fails, a significant pressure difference is formed collapsing the spring and blocks off most oil flow back to tank , helping to prevent an accident.

B. WHEN DISCONNECTED Figure 46. Velocity Fuse

54

Hydraulic System

VELOCITY FUSE A velocity fuse (throttle valve) is mounted within the oil circuit of lift cylinder, to limit the dropping speed under a heavy load (see Figure 47). Under normal conditions, the velocity fuse does not activate when hydraulic flow is generated from the lift function. Oil flows to the velocity fuse into cavities A, B, C, D, E, F and G and into the lift cylinder.

In an emergency situation, caused by a significant pressure drop in the system (ex. hydraulic hose burst), the velocity fuse actuates. The hydraulic fluid moves quickly from points G through A causing the internal body of the velocity fuse to the move to the right, closing off most oil flow. If this occurs the velocity fuse considerably reduces the flow of the hydraulic fluid leaving the cylinder, allowing the suspended load to safely be lowered.

1.

2.

3.

4.

5.

6.

7.

NORMAL FLOW THROTTLE FLOW SIDE OF MULTI-WAY VALVE VALVE BODY O-RING SPRING THROTTLE PLATE

8. VALVE SLEEVE 9. VALVE CORE 10. NYLON BALL 11. SPRING 12. CONNECTOR 13. SIDE OF LIFT CYLINDER

A. B. C. D.

VALVE CAVITY VALVE CAVITY VALVE HOLE VALVE HOLE

E. F. G. H.

VALVE CAVITY VALVE CAVITY VALVE CAVITY VALVE CAVITY

Figure 47. Limiting Valve

55

Hydraulic System

TILT CYLINDER The tilt cylinder is a double acting cylinder, mounted on each side of the mast.

The tilt cylinder assembly consist of the piston, piston rod, cylinder body, cylinder bottom, guide sleeve, and sealing parts. The piston and piston rods are welded

1.

2.

3.

4.

5.

CLEVIS DUST RING BAFFLE RING SEAL RING O-RING

together. One wear ring and two Yx seal rings are mounted on the outer edge of piston. A Yx seal ring and dust rings are pressed in the cylinder bore and matched with guide sleeve. The shaft sleeve supports the piston rod, while the seal ring, and dust rings prevent oil leaks and dust.

6. GUIDE SLEEVE 7. BEARING 8. O-RING 9. PISTON ROD 10. CYLINDER BODY

11. SEAL RING 12. WEAR RING 13. PISTON 14. SEAL RING

Figure 48. Tilting Cylinder When tilt spool valve is pushed forward, the highpressure fluid enters from the bottom of the cylinder, pushing the the piston forward and allowing the mast to mast to tilt forward by 6°. When spool valve is pulled

56

backwards, the fluid enters from the front end of cylinder body, to push the piston until the mast tips backwards by 12°.

Hydraulic System

MAINTENANCE OF HYDRAULIC PUMP

Inspection and Repair

Disassemble, Main Oil Pump

Clean disassembled metal parts with hydraulic fluid.

Inspect, repair, or replace according to following procedure.

NOTE: For the following procedures refer to Figure 55 and Figure 56.

1.

Clamp the pump gently on a vice stand after cleaning. Remove the bolts (item 12).

2.

Detach pump cover (item 1) and seal rings (items, 8, 9, 10, and 11).

3.

Remove the front-end cover (item 7) and seal rings.

4.

Remove bearings and gears (items 3-6) from pump body. Bearings may be removed by pressing the gears, if it is difficult to remove them.

1. INLET 2. WEAR AREA 3. OUTLET

Inspection of Pump Body 1.

The gear pump is designed so the gear rotates along the inner surface of the pump body. Under normal wear its wear area shall not exceed a length 1/3 of the inner edge of the pump body. If it reads ½ length, it indicates that the bearing and gear shaft are worn out. When size at "X" exceeds 39.180 mm (1.542 in.), replace the pump body. See Figure 49.

4. MAINTENANCE LIMIT SIZE 5. OUTLET SIDE Figure 49. Main Oil Pump

57

Hydraulic System Inspection of Bearing 2.

Inspect that the inner surface of bearing is smooth, and the contact surface is shown at the position about ½ at the inlet side. See Figure 50.The bearing must be replaced, if any of the following cases occurs.

A. INNER DIAMETER B. TOTAL LENGTH 1.

2.

3.

4.

OUTLET SCRATCH INLET GEAR SIDE Figure 50. Inspection of bearing a.

The trace of contact appears on the entire slide inner surface, and roughness is felt when scraped with a finger nail.

b.

Crack appears around the face, and roughness is felt when scraped with a finger nail.

c.

Foreign matter is on the internal slide surface or end face.

Most cases of failures are caused by dirty hydraulic oil. The whole oil circuit may be cleaned or the oil may be replaced. Some individual cases are attributed to overloaded safety valve, air corrosion, too high temperature, or too low viscosity. In the case when failures occur, leading to roughness or severe wear on the gear shaft or the surface of the gear, the gear and bearing shall be replaced. The limit size for bearing maintenance is: Inner Diameter—19.12 mm (0.75 in.)

Total Length—26.41 mm (1.04 in.)

58

Figure 51. Inner Bearing Inspection Inspection of Gear 3.

If clean hydraulic fluid is used, the gear shaft and gear surface will not be damaged. If roughness is felt on the surface, a crack occurs, or uneven wear is present, replace the gear. When gear surface is worn or discolored, it indicates that failure has also occurred, and must be inspected.

The limit size for the axial diameter of gear shaft is 18.94 mm (.075 in.).

A. 18.94 mm (.075 in.)

Figure 52. Gear Inspection

Hydraulic System Inspection of Oil Seal NOTE: For the following procedures refer to or . a.

Oil Seal (item 14) is a combination seal. The lip on inner side of the pump shaft provides sealing, while the lip at the outer side is for dust resistance. Check if crack, wear, or distortion exists on oil seal, and inspect whether or not the rubber is elastic.

b.

Replace seal rings (items 8-9) for bearing.

c.

Inspect seal rings (items 10-11) for wear and damage.

1.

2.

3.

4.

5.

6.

BEARING DRIVING GEAR INLET SIDE CLEARANCE NOT ALLOWED POSITIONING PIN (AT INLET SWITCH) DRIVEN GEAR Figure 54. Pump Body

1.

2.

3.

4.

DUST-PROOF LIP PUMP OUTER SIDE PUMP INNER SIDE SEAL RING NOZZLE Figure 53. Oil Seal Inspection

Assemble, Main Oil Pump NOTE: For the following procedures refer to Figure 55 or Figure 56.

1.

Clean the disassembled parts.

2.

Coat a thin layer of clean grease on the lips of oil seals.

3.

Place the pump body and the pump cover on a flat stand. Coat the inner surface of the pump body with clean hydraulic oil.

4.

Place bearings into the pump body, and pay attention to put them in correct positions. Do not press it in forcibly. See Figure 54.

5.

Turn over the pump body. Put the driving and driven gears (items 5-6) into the pump body, and allow the engaged teeth to be at the same position as prior to disassembly.

6.

Mount the bearings (items 3-4) on one side of the front end cover using the same method as in .

7.

Mount the seal ring for pump body (item 8), the seal ring for bearing (item 9), and seal rings (items 10-11), and do not allow the seal rings to overlap.

8.

Assemble the front end cover (item 7), and wrap the band around the end of driving gear to avoid damage of oil ring lip. Remove the band after the front end cover is mounted.

9.

When pump body is turned over to mount end cover, prevent seal rings from moving.

10. Mount seal rings (items 8-11), with the same method as in Step 7.

11. Put on the end cover (item 11).

59

Hydraulic System 12. Mount spring washer (item 13) and bolt (item 12), and torque to 47 N•m (34.67 lbf).

13. Inspect the gear pump to confirm it is assembled completely. Place the driving shaft into the vice stand, then turn pump and confirm it rotates easily.

Before this pump is reinstalled, check a second time to confirm it is assembled completely and the rotating direction is correct. a.

Check if the lower part is damaged or dirty.

b.

Check if the flange surface is damaged or dirty.

c.

Mount O-ring, after following the previous steps.

gauge should read slightly lower than 1 MPa (145.04 psi). Keep pump running for 10 minutes.

3.

Increase rotating speed to 1500-2000rpm, and allow to idle for 10 minutes.

4.

Keep the rotating speed at 1500-2000rpm, increase the pressure to 2-3 MPa (290.08-435.11 psi) for 5 minutes.

Repeat until maximum pressure is reached. Use overflow valve to increase the load to adjust pressure. Allow each fluid circuit to work for 5 minutes, and replace or clean the filter core of return filter. When pressure increases then, monitor fluid temperature of the pump body and overall proper functionality. If fluid temperature or pump temperature are too high, flush the pump immediately to lower the temperature, and repeat the process.

5.

After testing is complete ,make sure to set the hydraulic pressure back to required specs per the capacity specifications Manual.

Test Test the pump after assembly. Confirm the pump has reached the specified performance after reassembly.

Perform a test run after pump is installed into forklift truck. If pump is blocked or internal parts are excessively worn out, fluid must be replaced and filter must be replaced or cleaned.

NOTE: Unloading test must be performed, to ensure that this device has a proper speed.

1.

Install pressure gauge on high-pressure line near the pump.

NOTE: See Figure 55 and Figure 56 for gear oil pump structures in clockwise and counterclockwise rotations.

2.

Place the transmission in the NEUTRAL position, for pump to run at a speed of 500-1000rpm. While in the in the NEUTRAL position, the pressure

See Figure 57 for a diagram of hydraulic pipeline.

60

Hydraulic System

1.

2.

3.

4.

5.

END COVER PUMP BODY BEARING BEARING DRIVING GEAR

6. DRIVEN GEAR 7. FRONT END COVER 8. SEAL RING 9. SEAL RING 10. SEAL RING

11. SEAL RING 12. BOLT 13. LOCK WASHER 14. LOCKING COLLAR 15. OIL SEAL

Figure 55. Clockwise Rotation of Gear Pump (2-3.5T Gasoline Forklift Trucks)

61

Hydraulic System

1.

2.

3.

4.

5.

END COVER PUMP BODY BEARING BEARING DRIVING GEAR

6. DRIVEN GEAR 7. FRONT END COVER 8. SEAL RING 9. SEAL RING 10. SEAL RING

11. SEAL RING 12. BOLT 13. LOCK WASHER 14. OIL SEAL 15. LOCKING COLLAR

Figure 56. Counterclockwise Rotation of Gear Pump (2-3.5T Diesel Forklift Truck)

62

Hydraulic System

Figure 57. Hydraulic Schematic (Diesel and Gasoline Forklift Trucks)

63

Hydraulic System Legend for Figure 57.

1. HOSE CLAMP 2. PUMP SUCTION PIPE 3. PUMP SUCTION FITTING 4. 0-RING 35×3.5 5. GEAR PUMP 6. 0-RING 80×3.55 7. WASHER 10 8. WASHER 10 9. BOLT M10×35 10. 0-RING 22×2.4 11. PUMP OUTLET FITTING 12. VALVE H.P. HOSE 13. 0-RING 18×2.4 14. STEERING CYLINDER CONNECTOR 15. STEERING CYLINDER H.P. HOSE I 16. STEERING CYLINDER H.P. HOSE II 17. ORBITAL PIPE

64

18. HOOP D25 19. ORBITAL PIPE CONNECTOR 20. ORBITAL CONNECTOR I 21. ORBITAL CONNECTOR II 22. ORBITAL 23. MULTI-CHANNEL VALVEHOSE II 24. CONNECTOR 25. VALVE INLET CONNECTOR 26. 0-RING 24×2.4 27. MULTI-CHANNEL VALVE 28. MULTI-CHANNEL VALVE-TILT CYLINDER CONNECTOR 29. RETURN OIL HOSE 30. TILT CYLINDER PIPE I 31. TILT CYLINDER PIPE II 32. CLIP I 33. CLIP II 34. TILT CYLINDER HOSE (FRONT)

35. TILT CYLINDER CONNECTOR 36. 0-RING 16×2.4 37. BOLT M6×25 38. WASHER 6 39. WASHER 6 40. NUT M6 41. BOLT M6×12 42. CLIP 43. BOLT M8×20 44. WASHER 8 45. NUT M8 46. CLAMP PLATE 47. CLAMP 48. CLIP 49. CABLE TIE 50. DIVERTER CONNECTOR 51. DIVERTER CONNECTOR

Hydraulic System

TROUBLESHOOT HYDRAULIC SYSTEM Problem Fluid Level Low

Cause

Solution

Fluid level in tank is at low end

Fill fluid to the specified level

Fluid suction side pipeline or filter blocked

Clean or replace fluid if dirty

Bearings are worn, and bearing seal rings are at fault.

Replace

Overflow valve misadjusted

Raise pressure gauge Tighten joint at suction pipe side

Failure of Gear Pump for Supercharge

Add fluid into tank Air blended into pump

Check pump seal Run pump until there are no more air bubbles in fuel tank

Fluid suction hose twisted, or cavity blocked by filter Clean filter and adjust hose Air pulled inside due to loosening of fluid Noise of Gear Pump suction side joint Loud Excessive fluid viscosity Air bubble present in hydraulic fluid

Tighten each joint Use proper viscosity fluid Do not operate until fluid temperature is normal Check for cause of air bubble

Seal and seal ring of pump at fault Fluid Leak with Pump Sliding face worn (for internal leak to be increased)

Replace

65

Lifting System

Lifting System SAFETY PROCEDURES WHEN WORKING NEAR MAST WARNING The following procedures MUST be used when inspecting or working near the mast. Additional precautions and procedures can be required when repairing or removing the mast. See the correct Service Manual section for the specific mast being repaired.

•

• •

• •

Never put any part of the body into or under the mast or carriage unless all parts are completely lowered or a safety chain is installed. Also make sure that the power is off and the key is removed. Put a DO NOT OPERATE tag in the operator's compartment. Disconnect the battery on electric lift trucks and put a tag or lock on the battery connector.

Be careful of the forks. When the mast is raised, the forks can be at a height to cause an injury.

DO NOT climb on the mast or lift truck at any time. Use a ladder or personnel lift to work on the mast.

DO NOT use blocks to support the mast weldments or to restrain their movement.

Mast repairs require disassembly and removal of parts and can require removal of the mast or carriage. Follow the repair procedures in the correct Service Manual for the mast.

WHEN WORKING NEAR THE MAST ALWAYS: •

OR

66

Lower the mast and carriage completely. Push the lift/lower control lever forward and make sure there is no movement in the mast. Make sure that all parts of the mast that move are fully lowered.

•

If parts of the mast must be in a raised position, install a safety chain to restrain the moving parts of the mast. Connect moving parts to a part that does not move. Follow these procedures:

1.

Put mast in vertical position.

2.

Raise mast to align bottom crossmember of weldment that moves in the outer weldment with a crossmember on the outer weldment. On the two-stage and free-lift mast, the moving part is the inner weldment. On the three-stage mast, it is the intermediate weldment. See Figure 58.

3.

Use a 3/8 inch minimum safety chain with a hook to fasten the crossmembers together so the movable member cannot lower. Put the hook on the back side of the mast. Make sure the hook is completely engaged with a link in the chain. Make sure the safety chain does not touch lift chains or chain sheaves, tubes, hoses, fittings, or other parts on the mast.

4.

Lower mast until there is tension in the safety chain and the free-lift cylinder (three-stage) is completely retracted. If running, stop the engine.

Apply parking brake. Install a DO NOT REMOVE tag on the safety chain(s).

5.

Install another safety chain (3/8 inch minimum) between the top or bottom crossmember of the carriage and a crossmember on the outer weldment. See Figure 58.

NOTE: Apply parking brake. After lowering or restraining the mast, shut off power and remove key.

Put a DO NOT OPERATE tag in the operator's compartment. Disconnect battery on electric lift trucks and put a tag or lock on battery connector.

Lifting System

Figure 58. Two-Stage, Free-Lift, and Three-Stage Masts

67

Lifting System Legend for Figure 58.

A. TWO-STAGE MAST

B. FREE-LIFT MAST

C. THREE-STAGE MAST

1. OUTER WELDMENT 2. INNER WELDMENT

3. INTERMEDIATE WELDMENT 4. HOOK 5. FREE-LIFT CYLINDER

6. CROSSMEMBER 7. CROSSMEMBER

OVERVIEW The lifting system is a two-stage rolling telescopic mast, with the outside mast typical of a “C” shaped end face, and the inside mast in a “J” shaped end face. The fork and the bracket comply with the international standard, with a free lift of about 150mm 150 mm (5.9 in.) during operation.

Measurement A

54 mm (2.13 in.)

B

15 mm (0.59 in.)

C

18 mm (0.71 in.)

D

38 mm (1.50 in.)

E

92 mm (3.62 in.)

F

120 mm (4.72 in.)

G

160 mm (6.30 in.)

Figure 59. End Face of Inner Mast

68

Lifting System

Measurement A

55 mm (2.17 in.)

B

15 mm (0.59 in.)

C

120 mm (4.72 in.)

D

160 mm (6.30 in.)

Figure 60. End Face of Outer Mast

69

Lifting System

INSIDE AND OUTSIDE MASTS The mast assembly is composed of an inside, middle, and outside masts (the middle masts is only for the 3FFL mast). The lower portion of the outside mast is connected to the drive axle, with most of the weight supported by the axle housing. The tilt cylinder is connected to the frame of the truck and the outer mast channel. The mast is able to tip forward and reverse.

CARRIAGE The carriage is made up of a series of welded components that move up and down in the inner mast channel, with the help of load and side rollers.

The Mast on the 2-3.5T 2FFL has a total of three groups of composite load rollers and two groups of standard load rollers. At the mast maximum height, two standard load rollers will extend out of the top of the inner channel.

The fork is locked inside the groove on the bracket using lock pins, and the spacing of fork can be adjusted manually

ADJUSTMENT OF LIFTING SYSTEM 1.

Once carriage is placed into the inner channel of the mast, set the carriage height by placing a gauge block that is 76 mm (2.3 in.) high to set carriage height.

1.

2.

3.

4.

OUTER MAST COMBINATION ROLLER INNER MAST FORK CARRIAGE

2.

Lower the fork to the ground, adjust the tensioning force of lift chain, to make sure the tensioning degrees of both lift chains to be equivalent.

1.

2.

3.

4.

LOCKNUT I LOCKNUT II END CONNECTOR CHAIN

3.

When lift cylinder, inner mast and outer mast need to be disassembled or replaced, adjust the assembly distance as follows:

Drop the fork to the ground, and adjust the nut on the lift chain’s upper end to ensure that there is the distance A between the load roller and the inner mast. See Adjustment of Lifting System Forklift Model

A

2-2.5T

24-29 mm (.94-1.14 in.)

3-3.5T

19-24 mm (.75-.94 in.)

a.

70

Place the piston rod head onto the upper beam of the inner mast without adjusting shims.

Lifting System d.

Adjust the tension of the chains.

WARNING The backrest installed on the carriage has the function of lateral fork stop and must not be removed.

On carriages where there is no backrest, the lateral fork stops are made of two metal plates (one for each side of the carriage) whose part number is available in parts manual, fixed with two bolts. See Figure 61. Before operating the lift truck, make sure that the backrest or the lateral fork stop plates are always present and the bolts are properly tightened. Under no circumstances should the truck be used without these stops.

1.

2.

3.

4.

INNER MAST LIFT CYLINDER ADJUSTING WASHER UPPER BEAM OF THE INNER MAST b.

Raise the mast slowly until the maximum stroke of the cylinder is reached, check whether the two cylinders are synchronized.

c.

Add adjusting shims between piston rod head and the upper beam of the inner mast. Make sure the washer is 02.-0.5 mm (0.008-0.02 in.) thick.

NOTE: Safety precautions must be taken when adjusting the cylinder.

Figure 61. Lateral Fork Stop

71

Electrical System

Electrical System OVERVIEW The electrical system in this model series is a singleline electrical system that utilizes anode bonding in the truck’s electrical circuitry to ensure that the forklift truck works properly in various conditions. The electrical equipment is composed of following systems:

Power supply system The power supply system consists of battery, alternator, charging indicator light and other components. It supplies power to the electric equipment of the truck. The battery provides power prior to starting the forklift. The alternator provides power when the forklift runs, and at the same time charges the battery. The charging indicator light is used to display the charging status.

plugs, and on some ICE engines a distributor and spark plug wires are present for the ignition system to function.

Preheating system (diesel forklift truck) The preheating system mainly consists of preheating plug (glow plug), preheating relay and time relay. The preheating time is set to 10-13seconds, but can be adjusted through time relay. Diesel with ECU electric control system is available. A temperature sensor is equipped to detect whether the current temperature needs to be preheated to increase the service life of components.

Dash Instrument Display system

Starting system The starting system is composed of glow plug (diesel truck only), key switch, neutral switch, and starter lamp. The function of the starting system is to start the engine. After the key switch is turned on, the glow plug heats up. The starting system has neutral protection function; the truck will only start if the shift lever is at the neutral position.

The instrument display system is composed of a water temperature sensor, oil temperature sensor, fuel sensor, oil pressure switch, (on Diesel equipped forklifts), oil-water separators and other components.

Its function is to detect the operation of the forklift truck and displays it through the display. This allows the operator to understand the status of the forklift .

Lighting, sound and alarm system The system includes a variety of lighting equipment, signal lights, horn, buzzer, and other components.

Ignition system (ICE forklift truck) Gasoline equipped forklifts do not have a preheating components as diesel forklift do. They have spark Front Front combinatio combinatio n lamp n lights

Power (W) 27

Rear combinatio n light

Warning light

turning

width

width

brake

reverse steering

turning

10

10

5

21

21

10

21

ELECTRICAL BOX

1.

The electrical box houses fuses and relays. The fuses are used to protect the circuits to prevent damage due to short circuit. The relays are used to expand the switch capacity, making the small-capacity switch able to control high-power electrical items.

When installing and maintaining, do not touch the conductor of the battery. This may cause serious burns.

2.

When charging the battery, the positive and negative terminals can not be reversed. This will cause high temperature, burning, fumes or explosion.

BATTERY For truck with a maintenance-free battery, pay attention to the following:

72

Electrical System 3.

When performing the battery routine maintenance, wear goggles, rubber gloves and rubber shoes.

4.

The battery will produce flammable gas, therefore potential risk of explosion exists. It is necessary to avoid short circuits, spark occurrence, and any source of flame.

5.

Prohibit contact with the battery. The battery electrolyte is dilute sulfuric acid. If contacted with the skin, please immediately rinse affected area with water. If contacted with the eyes, rinse intensively with water and see a doctor as early as possible.

DESCRIPTION AND SUMMARY OF BASIC TRUCK OPERATIONS

Item

Description

Function

1

left turn indicator

indicating the work of the left turn signal of forklift

2

right turn indicator

indicating the right turn signal light of forklift

3

oil-water separation indicator lamp

indicating that the water content in the oil-water separator is too high and manual drainage is required

4

low oil pressure indicator lamp

indicating low engine oil pressure

5

Engine Warning Indicator

indicating the engine failure

6

Glow Plug Light

indicating that the Glow Plug works

73

Electrical System

Item

Description

Function

7

the handbrake indicator light

indicates that the handbrake is in pull state

8

charging indicator light

indicates that the battery is not charged by the motor

9

seat indicator light

Indicates that an Operator is present in seat

10

Hour indicator

Shows the hours that the forklift has operated since new

11

indicates the temperature of the engine

12

indicates the remaining fuel of gasoline or diesel

13

Excessive Transmission Temperature Indicator

14

neutral gear light

15

Issue with Air Filter

Monitor Air Flow Restriction

16

indicate the oil temperature of the transmission

shows the temperature of the transmission oil only

INTRODUCTION TO THE POWER DISTRIBUTION MODULE (PDM) NOTE: Three spare fuses are located within the PDM. The PDM is made up of flasher, fuses, and other electrical components. It functions as the forklift truck engine starting control, and protection circuit. It contains the relays and fuses, making the vehicle circuit maintenance more convenient. The see Figure 77 and/or Figure 78 for the ordinary and expanded PDM. Application and function requirements of PDM:

74

Shows the temperature of the transmission oil when it exceeds a certain threshold

The key controls the function of the main power supply, such as the starting function, preheating function, flasher, time relay, main power relay, starting relay, headlamp relay, preheating relay, and various other functions.

ELECTRICAL SCHEMATICS The schematic drawing of different engines differ from each other mainly on the starting system and on the sensor. It is suggested to refer to the specific drawing and real condition of the truck first when carrying out repair.

Electrical System

Figure 62. With NISSAN engine (K21, K25 Sheet 1 of 2)

75

Electrical System

Figure 63. With NISSAN engine (K21, K25 Sheet 2 of 2)

76

Electrical System

Figure 64. With PSI engine Sheet 1 of 2

77

Electrical System

Figure 65. With PSI engine Sheet 2 of 2

78

Electrical System

Figure 66. With Mitsubishi engine (S4S Sheet 1 of 2)

79

Electrical System

Figure 67. With Mitsubishi engine (S4S Sheet 2 of 2)

80

Electrical System

Figure 68. With Xinchai engine (Sheet 1 of 2)

81

Electrical System

Figure 69. With Xinchai engine (Sheet 2 of 2)

82

Electrical System

Figure 70. With Yanmar engine (92-98 Sheet 1 of 2)

83

Electrical System

Figure 71. With Yanmar engine (92-98 Sheet 2 of 2)

84

Electrical System

Figure 72. With Yanmar engine (94 Sheet 1 of 2)

85

Electrical System

Figure 73. With Yanmar engine (94 Sheet 2 of 2)

86

Electrical System

Figure 74. Optional Accessories

87

Electrical System

TROUBLESHOOT ELECTRICAL SYSTEM WARNING When examining the electrical wires, the key switch and battery grounding wire should be turned off and the wiring harness with the same serial number should be connected. Check the voltage of the electrical components. Avoid contact with conductive accessories to prevent short. Use the electric box wiring and schematic drawings as reference, and follow the steps below to inspect the wiring harness of the truck.

•

No damage on each electrical part

•

Each plug should be connected properly with no rust and dirt Each plug should maintain a safe distance of 10 mm (0.40 in.)from its ambient metal part.

The main wire shows no damage or decay

• • • • •

Each plug is labeled to avoid possible wrong connection All wiring should be kept away from high temperature objects like the exhaust system All wiring and fuel (gas) manifold should be kept away from high temperature objects like the exhaust system

When the truck fails, first check the electric box to inspect for damage to the time relay and fuse (the time relay will smell burned, if it is damaged). The middle of the fuse will be blown. Use a multimeter to check when these instances are not visible. Replace the damaged parts with new ones. The specification of the new fuse should not exceed that of the removed fuse.

Example 1: The IC truck could not be started •

88

Turn the key and listen to hear if the starting motor is working (engine will turn over). If starting motor is not functioning, perform the following.

1. Check if the gear is at neutral position (with OPS installed, whether the seat, seat belt and hand brake are in place).

2. Check if the negative end of the wiring is connected.

3. Check the start system (key switch) to confirm it functions correctly.

Check for damage at the starting motor. If 4. the starting motor functions properly, check if the oil supply system is working.

Example 2: The IC truck could be started but could not move forward or reverse • •

For manually controlled truck, the gear is controlled by the lever.

For the hydraulic controlled truck (With OPS installed, make sure that the seat and seat belt switch are off and hand brake is on), check the gear switch’s input and output voltage to see if it is 12V. 1. If there is no input, then check the power supply for the gear switch lever.

2. If it is with input voltage but without output voltage, it means that the gear switch lever is damaged 3. If it is with both input and output voltage, then check the voltage at where the directional valve is located.

4. If voltage exists, the valve or transmission is damaged. If there is no voltage, the wiring between the gear switch lever and directional valve is disconnected.

Troubleshooting Truck will not start 1. Check if the starting condition is met when the operator sits on the seat (whether the seat switch is closed and grounded).

2. Check if the starting conditions are met and the handbrake is pulled up (whether the handbrake switch is closed and grounded).

3. Check if the starting conditions are met. For Australian customers, if there is seat belt and seat starting sequence, whether the starting conditions are followed.

Lift, Lowering and Tilt functions are not working 1. Check if the seat switch is closed and grounded.

2. Check if the solenoid valve is closed. When the seat switch is closed and grounded, there should be 12V voltage input to the solenoid valve. When the seat switch is closed and grounded, there should be 12V voltage at the output end of the electrical box.

3. Check if the and socket connections are tight or loose.

4. Confirm there is voltage input to the solenoid valve. If valve is not working, check the solenoid valve spool.

Forward and reverse functions are not working 1. Check if the seat switch is closed and not grounded.

Electrical System 2. Check if the hand brake is pulled up. The hand brake switch should be disconnected and ungrounded.

3. Check if there is 12V voltage output when the combination switch is put into forward or reverse gear.

4. Check if there is 12V voltage input in the forward and reverse direction valve.

5. Check if the pin and socket connections are tight or loose.

6. Confirm there is voltage input to the direction valve. If the valve is not working, check the transmission direction valve.

89

Drive, Operation, and Routine Maintenance of Forklift Truck

Drive, Operation, and Routine Maintenance of Forklift Truck COOLING SYSTEM TROUBLESHOOTING AND SERVICE WARNING DO NOT operate a lift truck that needs repairs.

Report the need for repairs immediately. If repair is necessary, put a DO NOT OPERATE tag in the operators area. Remove the key from the key switch.

Safety labels are installed on the lift truck to give information about operation and possible hazards.

It is important that all safety labels are installed on the lift truck and can be read.

3.

Install the radiator cap.

Flushing the cooling system NOTE: Cleaning water used to flush the cooling system must be completely drained, and replaced with approved coolant to avoid freezing.

• •

Clean water can be used to flush to cooling system.

Periodically the radiator must be removed and cleaned in a 1% concentrated boiled soda solution. This removes scale and sediment formed that has formed in the radiator.

Adding antifreeze/coolant

Coolant must be less than 40°C (104°F) before draining the radiator or personal injury may occur

Add only approved type FD-2 -35°C (-31°F). Do not add water or any other antifreeze/coolants to the cooling system.

Coolant level check

Filter or replace the antifreeze/coolant after a year of use.

1.

If radiator coolant is boiling or temperature is too high, do not to open the radiator cap immediately.

If the forklift truck is running, bring the engine idle down to low or medium speed.

Loosen radiator cap slowly to relieve pressure.

Once there is no pressure, remove the radiator cap.

2.

Check coolant level. Add approved coolant as needed.

NOTE: Radiator cap must be installed completely. If the radiator cap is not tight, the cooling system can not build adequate pressure.

90

Cleaning the radiator The exterior of the radiator should be cleaned Periodically. Cleaning may be required more frequently depending on working conditions.

Use detergent, compressed air, or high-pressure water to clean the radiator. Pressure used to clean the radiator should not exceed 4 kg/cm ( 56.9 psi).

Drive, Operation, and Routine Maintenance of Forklift Truck

OILS USED FOR FORKLIFT TRUCK Name

Brand or Code (Domestic)

Gasoline

87 number gasoline.

Engine Oil

API rating of SM or newer

Hydraulic Oil

Kinematic Viscosity 28.8-35.2 cSt @ 104F (40℃ mm2/s） Kinematic Viscosity ≥5 cSt @ 212F (100℃ mm2/s)

Transmission Oil

Kinematic Viscosity 5-7 cSt @ 212F (100℃ mm2/s）

Gear Oil

API GL-5 85W-90

Brake Fluid

DOT4 Synthetic Brake Fluid

Grease (steer axle)

NLGI grade 2 lithium type complex grease (with minimum of 3% molybedenum disulphide additive)

Grease (rest of truck)

NLGI grade 2 lithium based grease

HYDRAULIC OIL GAUGE AND HYDRAULIC OIL FILL

•

H line indicates the maximum level of hydraulic oil required. If the reading on the dipstick is above this line, flush oil from the tank.

General inspection requirements 1.

Check the oil level of the hydraulic oil tank. Take the oil level trace as a reference. The mast, attachments, and steering system must be taken in consideration in order to fill the hydraulic system to the correct level.

2.

Forklift must be parked for five minutes before oil level can be checked.

3.

The engine must be OFF, the forklift truck must be on flat ground, the mast must be vertical state, forks must be on the ground, and attachments should be retracted. This ensures the hydraulic oil is back in the tank.

Fill Level Requirements NOTE: For items below, refer to Figure 75.

•

•

L line indicates the lowest level of hydraulic oil required to operate the mast up to 4 m (13.1 ft) in height (including the full free lift mast and mast with special attachment).

M line indicates the lowest level of hydraulic oil required to operate the mast ABOVE4 m (13.1 ft) in height (including the full free lift mast and mast with special attachment).

A. FILL LEVEL REQUIRED FOR MAST ABOVE 4 m (13.1 ft), WITH ATTACHMENTS. B. FILL LEVEL REQUIRED FOR MAST BELOW 4 m (13.1 ft), WITH ATTACHMENTS. Figure 75. Oil Fill Stick

91

Drive, Operation, and Routine Maintenance of Forklift Truck

LUBRICATION SYSTEM

Figure 76. Lubricating System

92

PDM Schematics

PDM Schematics

93

NOTES

94

Figure 77. PDM (Suitable For All Engines)

95/(96 blank)

Figure 78. PDM With OPS (Suitable For All Engines)

97/(98 blank)

TECHNICAL PUBLICATIONS 4/22 (1/21)(10/20)(6/19)(5/19)(4/19)