Hyster B453 (W40ZA) Forklift Service Repair Manual

SERVICE REPAIR W30ZA W40ZA [B453]

2000 SRM 1025

Description of Operation

General This section covers the troubleshooting and repair procedures for the hydraulic components on the W30/ 40ZA, W25/30/40ZC, and W20/30ZR lift trucks.

For troubleshooting and repairs of the electrical components, see Electrical System 2200 SRM 1026 and ZAPI TM Controllers 2200 SRM 1064.

It also includes the remove and install procedures for the solenoid coils used to activate the hydraulic valves.

Description of Operation The hydraulic system of the W30/40ZA, W25/30/ 40ZC, and W20/30ZR lift trucks includes: • Reservoir • Pump • Check valve • Relief valve • Proportional lowering valve • Lift cylinder(s) • Connecting hoses and tubes Based on the model and configuration of the hydraulic system, it can also include: • Lift valve • Directional valve(s) • Selector valve(s) • Counterbalance valve • Pilot operated check valve • Sideshift cylinder • Tilt cylinders • Reach cylinders • Auxiliary cylinder(s) The reservoir contains the hydraulic fluid necessary for the operation of the system. It acts as a heat sink to provide cooling. As the hydraulic oil leaves the reservoir, it is filtered through an internal strainer in the reservoir.

The hydraulic pump provides the flow of the hydraulic oil. It moves the oil to activate the cylinders.

A check valve provides flow of the hydraulic oil in one direction only. In this hydraulic system, it prevents the oil from flowing backwards through the pump.

A relief valve limits maximum pressure to protect the hydraulic system components.

The proportional lowering valve is a normally closed valve. When it opens, hydraulic oil from the lift cylinders is allowed to return to the reservoir and the forks lower. Rate of flow is regulated by how far the valve opens.

The lift cylinder(s) rod extends to raise the forks through a series of mast channels and chains.

The connecting hoses and tubing connect the various hydraulic components in the lift truck to complete the hydraulic circuit.

The lift valve is used on systems that have more than a lift/lower function. It is a normally closed valve which opens during the lift function. During other functions, such as sideshift, it remains closed to prevent flow to the lift cylinders.

The directional valve(s) is a three position normally closed valve located on the pump. In its normal position, it blocks the flow of oil to a double acting cylinder, such as a sideshift cylinder. Activated in one position, it provides flow to extend a cylinder rod. Activated in the opposite position, it reverses flow to the cylinder to retract the cylinder rod.

The selector valve(s) is a normally closed valve located on the mast. Selector valves are used to direct the flow from a single pair of hydraulic lines to multiple double acting hydraulic cylinders.

The counterbalance valve provides free flow in one direction and resistance to flow in the opposite direction. It is located in the tilt circuit to control forward tilt.

The pilot operated check valve is located in the retract circuit and is activated by an auxiliary pressure. Its function is to maintain pressure on the rod side of the piston to hold the reach mechanism in the retract position.

The tilt cylinders rods extend to tilt the forks forward away from the lift truck. The rods retract to tilt the forks back toward the lift truck.

The reach cylinders rods extend to move the forks away from the lift truck. The rods retract to move the forks back toward the lift truck.

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Special Precautions

2000 SRM 1025

The function of the auxiliary cylinder(s) varies based on the optional attachment.

3. Filter each change of oil to prevent the introduction of contaminants into the system.

HYDRAULIC OIL

4. Provide continuous protection from airborne contamination by keeping the breather cap clean and serviceable.

The hydraulic oil in the system performs the dual function of power transmission and lubrication. Using the correct fluid is essential to proper system operation. See Periodic Maintenance 8000 SRM 1027 for the recommended hydraulic oil.

The level in the reservoir should be checked first when troubleshooting lifting problems. Low oil levels may make it appear that a problem exists with the battery or hydraulic system.

CLEAN Adhere to the following precautionary steps to be sure that the hydraulic system remains clean.

1. Clean the reservoir and pump area to prevent contaminants from entering the hydraulic system.

2. Clean (flush) the entire system when a failure is encountered to make sure all contaminants, debris, and foreign objects are removed.

SOUND LEVEL Hydraulic system noise may be caused by both improperly selected oil and loose or damaged system components.

• Cavitation - Can be caused by high fluid viscosity, cold fluid temperatures, or a restriction in the inlet screen or inlet tubing. At startup, low temperatures can cause pump noises due to cavitation.

• Aerated hydraulic oil - Results in system noise that is similar to cavitation. Aerated oil is caused by the ingestion of air through the pipe joints of the inlet lines and high-velocity discharge lines, as well as cylinder rod packing. Aeration can also be caused by oil discharging above the fluid level in the hydraulic reservoir. Air does not have sufficient time to escape from the fluid while in the reservoir before recycling through the system.

Special Precautions WARNING The capacitor in the transistor controller can hold and electrical charge after the battery is disconnected. To prevent an electrical shock and personal injury, discharge the capacitor before inspecting or repairing any component in the drive unit compartment. Wear safety glasses. Make certain that the battery has been disconnected.

CAUTION To avoid controller damage, always disconnect the battery, discharge the capacitor, and never put power to the controller while any power

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wires are disconnected. Never short any controller terminal or motor terminal to the battery. Make sure to use proper procedure when servicing the controller.

1. Verify that the key switch is in the OFF position and the battery connector is completely disconnected.

2. Discharge the capacitors in the controllers by connecting a 200-ohm, 2-watt resistor across the controller’s B+ and B terminals. DO NOT short across the motor controller terminals with a screwdriver or jumper wire. Remove the 200-ohm, 2-watt resistor before reconnecting the battery. See Figure 1.

2000 SRM 1025

Control Valve Legend for Figure 1 1.

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NEGATIVE CONNECTION POSITIVE CONNECTION 200-OHM, 2-WATT RESISTOR INSULATED JUMPER WIRES

Figure 1. Discharging the Capacitor

Control Valve CAUTION The hydraulic oil must be kept clean to prevent damage to the control valve.

The control valve is part of the lift pump and motor assembly and is replaceable but not adjustable.

When the operator selects a hydraulic function by pressing a button on the control handle, a signal is

sent to the traction/lift controller, is processed, and is sent to the pump assembly. Lifting speed is controlled by varying the pump motor speed. Lowering speed is controlled by a proportional electro-hydraulic valve on the pump assembly.

The control valve is designed with close tolerances and must be kept clean to work properly.

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Manual Lowering

2000 SRM 1025

Hydraulic Reservoir DESCRIPTION The hydraulic reservoir is made of a durable, translucent plastic that allows the operator to see how much hydraulic oil is in the reservoir. The reservoir is clamped to the adapter plate on the bottom of the pump and motor assembly in the drive unit compartment or hydraulic unit compartment.

The reservoir has either a graduated scale or MIN and MAX marks on the side depending on model and should only be filled with hydraulic oil to the graduated scale or MIN mark. See Table 1. There is a fill cap located on the top of the reservoir and a drain plug and O-ring located at the bottom on one side of the reservoir.

Table 1. Hydraulic Reservoir Model

Description

Reservoir Markings

Hydraulic Oil Quantity

W25/30/40ZC

Counterbalance

MIN/MAX

11.5 liter (12.2 qt)

W30/40ZA

Straddle Stacker

Graduated Scale

11 liter (11.6 qt)

W20/30ZR

Reach Carriage

Graduated Scale

11 liter (11.6 qt)

Manual Lowering WARNING Always verify that no one is under or near the lift mechanism or load during the manual lowering procedure. Verify that there are no obstructions beneath the lift mechanism or load. If the mast does not lower when the manual lowering valve is activated, deactivate the valve immediately and determine the cause.

WARNING Failure to return the manual lowering screw to the full clockwise position will cause the forks to lower unexpectedly.

A provision is provided on the lowering valve to allow manual lowering of the forks if necessary.

Manual lowering is accomplished by turning the

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manual override screw counterclockwise with a 7-mm wrench. In this position, the valve will remain open.

Loosen the manual override screw SLOWLY until the forks begin to lower. Be sure to return the screw to the original position once the manual lowering process is complete by slowly turning the screw until it stops. Torque the manual override screw to 4.0 N•m (36 lbf in).

On the W30-40ZA models without sideshift, the manual override screw is located on the back of the lowering solenoid near the mounting wall. See Figure 2.

On all other trucks with auxiliary functions, the manual override screw is located under the lowering solenoid block above the hydraulic reservoir. See Figure 3.

2000 SRM 1025

Manual Lowering

Figure 2. Single Function - Manual Lowering Screw (Top View)

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Lift Pump and Motor Repair

2000 SRM 1025

Figure 3. Auxiliary Function - Manual Lowering Screw (Side View)

Lift Pump and Motor Repair GENERAL The hydraulic pump and motor assembly has different parts working together to perform the functions of the hydraulic system. The pump is not repairable and must be replaced when it is not functioning properly. When replacement of the pump is necessary, the entire hydraulic pump and motor assembly and the hydraulic reservoir must be removed and disassembled. Some components may be replaced without totally disassembling the hydraulic pump and motor assembly. An electric motor drives the hydraulic pump. It may be removed without removing the entire assembly from the drive unit compartment or hydraulic unit compartment. Do only the steps necessary to perform the repairs needed.

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The lift pump and motor are connected by capscrews and are located on top of the hydraulic reservoir inside the drive unit compartment or hydraulic unit compartment.

NOTE: It is not necessary to remove the complete lift pump and motor assembly to remove the pump motor. When removing only the pump motor, see Remove Pump Motor.

REMOVE LIFT PUMP AND MOTOR ASSEMBLY 1. Move the lift truck to a safe and level area.

2. Lower the forks completely to relieve pressure from the hydraulic system.

2000 SRM 1025

Lift Pump and Motor Repair

3. Turn key switch to OFF position and disconnect battery.

4. Block load wheels to prevent lift truck from moving. Refer to Periodic Maintenance 8000 SRM 1027.

5. Remove drive unit compartment cover. On W25/ 30/40ZC lift trucks, also remove the hydraulic compartment cover.

6. Discharge the capacitor. tions.

See Special Precau-

For the following procedures, refer to Figure 5 for W30/40ZA lift trucks, Figure 6 for W20/30ZR lift trucks, and Figure 7 for W25/30/40ZC lift trucks.

7. Tag, identify, and disconnect the power wires to the lift pump motor.

8. Tag and identify the control wiring plugs and valve coils.

9. Remove the locking screws from the control wiring plugs. Disconnect the plugs from the coils.

WARNING Hydraulic oil hoses and lines may be under high pressure. Hydraulic oil can be injected into the body by pressure. To prevent possible injury, shield yourself from any escaping oil.

Wrap a rag around the fitting and loosen the fitting and loosen the connection slowly.

CAUTION To prevent dirt or contaminants from entering the hydraulic system, always install caps on the hoses and ports of the pump.

10. Tag, identify, and disconnect the hydraulic hoses.

11. The lift pump is attached to the frame with a bracket and vibration isolators. Remove the two nuts and washers attaching the mounting bracket to the isolators. See Figure 4.

12. Tilt the top of the lift pump and motor assembly away from the frame and lift up to remove.

13. Place hydraulic pump and motor assembly on the floor securely supported in an upright position.

The reservoir is unstable in an upright position and must be securely supported at all times.

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LIFT PUMP AND MOTOR ASSEMBLY CAPSCREW LOCKWASHER PUMP MOUNTING BRACKET NUT WASHER RUBBER ISOLATOR COUNTERSUNK CAPSCREW Figure 4. Lift Pump and Motor Assembly

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Lift Pump and Motor Repair

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MOTOR COUPLING HYDRAULIC RESERVOIR CLAMP DRAIN PLUG AND O-RING BREATHER/FILLER CAP VALVE BLOCK PROPORTIONAL VALVE (LOWERING) PUMP

2000 SRM 1025

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TUBE PRESSURE RELIEF VALVE CHECK VALVE SCREW RESERVOIR MOUNTING BRACKET SCREWS SCREWS CAPSCREWS

Figure 5. Lift Pump and Motor Assembly-Without Auxiliary (W30/40ZA)

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2000 SRM 1025

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Lift Pump and Motor Repair

MOTOR COUPLING PUMP HOUSING HYDRAULIC RESERVOIR CLAMP DRAIN PLUG AND O-RING MAIN VALVE BLOCK PLUG PROPORTIONAL VALVE (LOWERING) LIFT VALVE AND COIL CAPSCREWS

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BREATHER/FILLER CAP SCREW AUXILIARY VALVE BLOCK DIRECTIONAL VALVE TUBES PRESSURE RELIEF VALVE CHECK VALVE SCREW ADAPTOR PLATE SCREW

Figure 6. Lift Pump and Motor Assembly With Auxiliary (W20/30ZR)

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Lift Pump and Motor Repair

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MOTOR COUPLING PUMP HOUSING HYDRAULIC RESERVOIR SCREW DRAIN PLUG AND O-RING CLAMPS AND O-RING MAIN VALVE BLOCK PROPORTIONAL VALVE (LOWERING) LIFT VALVE AND COIL

2000 SRM 1025

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BREATHER/FILLER CAP AND ELBOW SCREW PLUG AUXILIARY VALVE BLOCK VALVE (TILT) VALVE (SIDESHIFT) TUBE PRESSURE RELIEF VALVE CHECK VALVE CAPSCREWS

Figure 7. Lift Pump and Motor Assembly With Auxiliary (W25/30/40ZC)

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2000 SRM 1025

Lift Pump and Motor Repair

DISASSEMBLE

Remove Pump Motor

Remove Reservoir

1. If the lift pump and motor assembly has not been previously removed, perform steps 1 through 6 in Remove Lift Pump and Motor Assembly.

For the following procedures, refer to Figure 5 for W30/40ZA lift trucks, Figure 6 for W20/30ZR lift trucks, and Figure 7 for W25/30/40ZC lift trucks.

1. Use the following procedure that applies to your lift truck: a. Remove the screw from the clamp and remove the clamp from the reservoir and adaptor. b. Remove the four capscrews from the clamps and remove the clamps from the reservoir and the adaptor.

2. Lift the hydraulic pump and motor assembly from the reservoir.

3. Place pump and motor assembly on a clean drip pan in a horizontal position.

4. Remove and inspect the O-ring seal located between the hydraulic pump assembly and the reservoir. Verify that the O-ring seal is not damaged. Replace as needed.

5. Inspect the inlet strainer. If necessary, remove the retaining clip to access the screen. Replace parts that cannot be cleaned or are damaged.

CAUTION

2. Tag and disconnect the power wires from the lift pump motor.

3. Remove the two nuts and washers attaching the lift pump mounting bracket to the rubber vibration isolators.

4. Tilt the lift pump and motor assembly forward, away from the frame to gain access to the two capscrews on the top of the lift pump motor.

5. Remove two capscrews from top of motor.

6. Lift the motor from the pump assembly.

7. Inspect the motor output shaft, the pump input shaft, and the coupling. Replace worn or damaged parts.

Disassemble Pump For the following procedures, refer to Figure 5 for W30/40ZA lift trucks, Figure 6 for W20/30ZR lift trucks, and Figure 7 for W25/30/40ZC lift trucks.

1. Remove the two capscrews and lockwashers that hold pump mounting bracket to pump and remove bracket. See Figure 4.

Disposal of lubricants and fluids must meet local environmental regulations.

2. Separate reservoir adaptor plate from pump by removing attaching hardware (W20/30ZR and W30/40ZA only).

6. Pour oil from reservoir into a container suitable for disposal.

3. Tag and identify each tube and their corresponding locations.

CAUTION If oil is contaminated or excessively dirty, the entire hydraulic system should be thoroughly cleaned.

7. Examine the hydraulic reservoir. Inspect hydraulic reservoir for dirt, foreign materials, or contamination. Clean and flush the hydraulic reservoir as necessary.

4. Remove tubes and associated items from bottom of pump.

5. Use the following procedure that applies to your lift truck: a. Remove four screws retaining auxiliary valve block to pump. b. Remove four screws retaining valve block to pump. c. Remove the two fasteners retaining the main valve block to the pump.

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Lift Pump and Motor Repair 6. Remove relief valve and check valve from pump.

See Relief Valve and Check Valve, Remove.

7. Remove the coupling.

8. Use the following procedure that applies to your lift truck: a. Remove main valve block from pump housing. b. Remove plugs from auxiliary ports.

2000 SRM 1025

Install Pump Motor 1. Lubricate the motor output shaft and the pump input shaft with a light coating of multi - purpose #2 grease with 2% to 4% molybdenum disulfide.

2. Install the coupling on the pump shaft.

3. Align the slot in the motor shaft with the coupling. Lower the motor onto the pump, rotating the body as necessary to engage the coupling and then align the capscrews.

ASSEMBLE

4. Tighten the capscrews to 8 N•m (71 lbf in).

Assemble Pump

Install Reservoir to Pump

For the following procedures, refer to Figure 5 for W30/40ZA lift trucks, Figure 6 for W20/30ZR lift trucks, and Figure 7 for W25/30/40ZC lift trucks.

1. Place reservoir in an upright position on the floor.

1. Position pump mounting bracket to pump and install two capscrews and lockwashers to secure.

Torque the capscrews to 20 N•m (15 lbf ft). See Figure 4.

2. Install tubes and related items to bottom of pump as removed.

3. Secure reservoir adaptor plate to pump by installing attaching hardware.

4. Use the following procedure that applies to your lift truck: a. Install auxiliary valve block to pump using four screws and torque to 22 N•m (16 lbf ft). b. Install valve block to pump using four screws and torque to 22 N•m (16 lbf ft). c. Install the main valve block to the pump using two fasteners and torque to 22 N•m (16 lbf ft).

5. Install the relief valve and check valve. See Relief Valve and Check Valve, Install.

6. Use the following procedure that applies to your lift truck: a. Install main valve block to pump housing and torque the capscrews to 22 N•m (16 lbf ft). b. Install plugs into auxiliary ports in pump housing and torque to 22 N•m (16 lbf ft).

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NOTE: The reservoir may be filled at this point or it may be filled after the lift pump and motor assembly has been installed.

2. Fill reservoir with hydraulic oil to proper level.

See Table 1.

3. Install the O-ring seal on the pump assembly. If necessary, use a small amount of grease to hold the O-ring seal in position.

4. Position the lift pump and motor assembly onto the reservoir.

5. Use the following procedure that applies to the hydraulic reservoir for your lift truck: a. Install the clamp to the reservoir and adaptor using the screw to tighten. b. Install the clamps to the reservoir and the adaptor and install the four capscrews to secure the clamps.

INSTALL LIFT PUMP AND MOTOR ASSEMBLY 1. Install hydraulic lift pump and motor assembly in the lift truck and secure with the two nuts and washers. Torque the nuts to 15 N•m (11 lbf ft).

2. Connect the control wiring plugs to the coils as noted on tags.

3. Install the locking screws into the coil plugs.

4. Install the hydraulic hoses to the lift pump and motor assembly as noted on tags.

2000 SRM 1025

Valve Repair

5. Connect the power wires to the lift pump motor with the two nuts and washers. Torque the nuts to 4.0 N•m (35 lbf in).

6. Fill reservoir with hydraulic oil to proper level.

See Table 1.

7. Connect battery and turn key switch to ON position.

8. Operate each hydraulic function several times to purge the air from the hydraulic circuit.

9. Check the top of the lift cylinder to determine if a buttonhead bleed screw is present. If a bleed screw is present, bleed the air from the hydraulic system. See Bleed Hydraulic System.

10. Check hydraulic oil level in reservoir and fill to proper level. See Table 1.

11. Test lift truck by lifting and lowering a load several times. Check for leaks.

12. Install the drive unit compartment cover. If necessary, install the hydraulic unit compartment cover.

Valve Repair PROPORTIONAL VALVE (LOWERING) Remove 1. Move lift truck to a safe and level area.

2. Lower the forks completely to relieve pressure from the hydraulic system.

7. Tag and disconnect any power wires or hydraulic hoses blocking access to the valve.

8. Remove the locking screw from the control wiring plug. Disconnect the plug from the coil.

9. Remove the retaining clip and washer.

10. Slide the coil off of the valve.

3. Turn key switch to OFF position and disconnect battery.

4. Block load wheels to prevent lift truck from moving. Refer to Periodic Maintenance 8000 SRM 1027.

11. Remove the valve cartridge.

Install 1. Verify that the O-rings on the valve cartridge are not damaged. Replace as needed.

5. Remove the drive unit compartment cover. On W25/30/40ZC lift trucks, also remove the hydraulic compartment cover.

2. Verify that the valve cartridge and valve block are clean and not damaged.

6. Discharge the capacitor. tions.

3. Lubricate the valve cartridge threads and O-rings with clean hydraulic oil.

See Special Precau-

WARNING Hydraulic oil hoses and lines may be under high pressure. Hydraulic oil can be injected into the body by pressure. To prevent possible injury, shield yourself from any escaping oil.

Wrap a rag around the fitting and loosen the fitting and loosen the connection slowly.

CAUTION To prevent dirt or contaminants from entering the hydraulic system, always install caps on the hoses and ports of the pump.

4. Install the valve cartridge and torque to 27 N•m (20 lbf ft).

5. Slide the coil onto the valve cartridge with the lettering out towards the coil retainer.

6. Install the washer and retaining clip.

7. Connect any power wires and hydraulic hoses previously disconnected.

8. Connect the control wiring plug to the coil.

9. Install the locking screw into the coil plug.

10. Connect battery and turn key switch to ON position.

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Valve Repair

2000 SRM 1025

11. Operate each hydraulic function several times to purge the air from the hydraulic circuit.

8. Tag and identify the control wiring plugs and valve coils.

12. Check the top of the lift cylinder to determine if a buttonhead bleed screw is present. If a bleed screw is present, bleed the air from the hydraulic system. See Bleed Hydraulic System.

9. Remove the locking screws from the control wiring plugs. Disconnect the plugs from the coils.

13. Check hydraulic oil level in reservoir and fill to proper level. See Table 1.

14. Test the lift truck by lifting and lowering a load several times. Check for leaks.

15. Install the drive unit compartment cover. If necessary, install the hydraulic unit compartment cover.

DIRECTIONAL VALVE

1. Move lift truck to a safe and level area.

2. Lower the forks completely to relieve pressure from the hydraulic system.

3. Turn key switch to OFF position and disconnect battery.

4. Block load wheels to prevent lift truck from moving. Refer to Periodic Maintenance 8000 SRM 1027.

5. Remove the drive unit compartment cover. On W25/30/40ZC lift trucks, also remove the hydraulic compartment cover.

See Special Precau-

WARNING Hydraulic oil hoses and lines may be under high pressure. Hydraulic oil can be injected into the body by pressure. To prevent possible injury, shield yourself from any escaping oil.

Wrap a rag around the fitting and loosen the fitting and loosen the connection slowly.

CAUTION To prevent dirt or contaminants from entering the hydraulic system, always install caps on the hoses and ports of the pump.

7. Tag and disconnect any power wires or hydraulic hoses blocking access to the valve.

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11. Remove the spacer and the rear coil.

12. Remove the valve cartridge.

Install 1. Verify that the O-rings on the valve cartridge are not damaged. Replace as needed.

2. Verify that the valve cartridge and valve block are clean and not damaged.

Remove

6. Discharge the capacitor. tions.

10. Remove the nut and slide the front coil off the valve.

3. Lubricate the valve cartridge threads and O-rings with clean hydraulic oil.

4. Install the valve cartridge and torque to 34 N•m (25 lbf ft).

5. Slide the rear coil onto the valve cartridge with the lettering out towards the front coil.

6. Slide the spacer and then the front coil onto the valve cartridge with the lettering out towards the coil retainer.

7. Install the nut and torque to 7 N•m (60 lbf in).

8. Connect the control wiring plugs to the coils as noted on the tags.

9. Install the locking screws into the coil plugs.

10. Connect any power wires and hydraulic hoses previously disconnected.

11. Connect battery and turn key switch to ON position.

12. Operate each hydraulic function several times to purge the air from the hydraulic circuit.

13. Check the top of the lift cylinder to determine if a buttonhead bleed screw is present. If a bleed screw is present, bleed the air from the hydraulic system. See Bleed Hydraulic System.

14. Check hydraulic oil level in reservoir and fill to proper level. See Table 1.