WALKIE HIGH LIFT HYDRAULIC SYSTEM

Transcription

1 WALKIE HIGH LIFT HYDRAULIC SYSTEM W30-40ZA [B453]; W20-30ZR [B455]; W ZC [B454] PART NO SRM 1025

2 SAFETY PRECAUTIONS MAINTENANCE AND REPAIR When lifting parts or assemblies, make sure all slings, chains, or cables are correctly fastened, and that the load being lifted is balanced. Make sure the crane, cables, and chains have the capacity to support the weight of the load. Do not lift heavy parts by hand, use a lifting mechanism. Wear safety glasses. DISCONNECT THE BATTERY CONNECTOR before doing any maintenance or repair on electric lift trucks. Disconnect the battery ground cable on internal combustion lift trucks. Always use correct blocks to prevent the unit from rolling or falling. See HOW TO PUT THE LIFT TRUCK ON BLOCKS in the Operating Manual or the Periodic Maintenance section. Keep the unit clean and the working area clean and orderly. Use the correct tools for the job. Keep the tools clean and in good condition. Always use HYSTER APPROVED parts when making repairs. Replacement parts must meet or exceed the specifications of the original equipment manufacturer. Make sure all nuts, bolts, snap rings, and other fastening devices are removed before using force to remove parts. Always fasten a DO NOT OPERATE tag to the controls of the unit when making repairs, or if the unit needs repairs. Be sure to follow the WARNING and CAUTION notes in the instructions. Gasoline, Liquid Petroleum Gas (LPG), Compressed Natural Gas (CNG), and Diesel fuel are flammable. Be sure to follow the necessary safety precautions when handling these fuels and when working on these fuel systems. Batteries generate flammable gas when they are being charged. Keep fire and sparks away from the area. Make sure the area is well ventilated. NOTE: The following symbols and words indicate safety information in this manual: WARNING Indicates a condition that can cause immediate death or injury! CAUTION Indicates a condition that can cause property damage!

3 Walkie High Lift Hydraulic System Table of Contents TABLE OF CONTENTS General... 1 Description of Operation... 1 Hydraulic Oil... 2 Clean... 2 Sound Level... 2 Special Precautions... 2 Control Valve... 3 Hydraulic Reservoir... 4 Description... 4 Manual Lowering... 4 Lift Pump and Motor Repair... 6 General... 6 Remove Lift Pump and Motor Assembly... 6 Disassemble Remove Reservoir Remove Pump Motor Disassemble Pump Assemble Assemble Pump Install Pump Motor Install Reservoir to Pump Install Lift Pump and Motor Assembly Valve Repair Proportional Valve (Lowering) Remove Install Directional Valve Remove Install Lift Valve Remove Install Counterbalance Valve W20/30ZR Remove Install W25/30/40ZC Remove Install Relief Valve and Check Valve Remove Install Pilot Operated Check Valve W20/30ZR Remove Install Selector Valves: Reach, Tilt, and Sideshift W20/30ZR and W25/30/40ZC Remove Install Relief Valve Adjustment HYSTER COMPANY i

4 Table of Contents Walkie High Lift Hydraulic System TABLE OF CONTENTS (Continued) Bleed Hydraulic System Troubleshooting Hydraulic Diagrams and Schematics This section is for the following models: W30-40ZA [B453]; W20-30ZR [B455]; W ZC [B454] ii

5 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 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. 1

6 Special Precautions 2000 SRM 1025 The function of the auxiliary cylinder(s) varies based on the optional attachment. HYDRAULIC OIL 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. 3. Filter each change of oil to prevent the introduction of contaminants into the system. 4. Provide continuous protection from airborne contamination by keeping the breather cap clean and serviceable. 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 sufficienttimetoescapefromthefluidwhileinthe reservoir before recycling through the system. 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 Special Precautions 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. SeeFigure1. 2

7 2000 SRM 1025 Control Valve Legend for Figure 1 1. NEGATIVE CONNECTION 2. POSITIVE CONNECTION OHM, 2-WATT RESISTOR 4. INSULATED JUMPER WIRES Figure 1. Discharging the Capacitor 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 Control Valve 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. 3

8 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 isafillcaplocatedonthetopofthereservoiranda 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) 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 Manual Lowering manual override screw counterclockwise with a 7-mm wrench. In this position, the valve will remain open. Loosen the manual override screw SLOWLY until theforksbegintolower.besuretoreturnthescrew 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. 4

9 2000 SRM 1025 Manual Lowering Figure 2. Single Function - Manual Lowering Screw (Top View) 5

10 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. 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. 6

11 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 Remove drive unit compartment cover. On W25/ 30/40ZC lift trucks, also remove the hydraulic compartment cover. 6. Discharge the capacitor. See Special Precautions. 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 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. 1. LIFT PUMP AND MOTOR ASSEMBLY 2. CAPSCREW 3. LOCKWASHER 4. PUMP MOUNTING BRACKET 5. NUT 6. WASHER 7. RUBBER ISOLATOR 8. COUNTERSUNK CAPSCREW Figure 4. Lift Pump and Motor Assembly 7

12 Lift Pump and Motor Repair 2000 SRM MOTOR 2. COUPLING 3. HYDRAULIC RESERVOIR 4. CLAMP 5. DRAIN PLUG AND O-RING 6. BREATHER/FILLER CAP 7. VALVE BLOCK 8. PROPORTIONAL VALVE (LOWERING) 9. PUMP 10. TUBE 11. PRESSURE RELIEF VALVE 12. CHECK VALVE 13. SCREW 14. RESERVOIR MOUNTING BRACKET 15. SCREWS 16. SCREWS 17. CAPSCREWS Figure 5. Lift Pump and Motor Assembly-Without Auxiliary (W30/40ZA) 8

13 2000 SRM 1025 Lift Pump and Motor Repair 1. MOTOR 2. COUPLING 3. PUMP HOUSING 4. HYDRAULIC RESERVOIR 5. CLAMP 6. DRAIN PLUG AND O-RING 7. MAIN VALVE BLOCK 8. PLUG 9. PROPORTIONAL VALVE (LOWERING) 10. LIFT VALVE AND COIL 11. CAPSCREWS 12. BREATHER/FILLER CAP 13. SCREW 14. AUXILIARY VALVE BLOCK 15. DIRECTIONAL VALVE 16. TUBES 17. PRESSURE RELIEF VALVE 18. CHECK VALVE 19. SCREW 20. ADAPTOR PLATE 21. SCREW Figure 6. Lift Pump and Motor Assembly With Auxiliary (W20/30ZR) 9

14 Lift Pump and Motor Repair 2000 SRM MOTOR 2. COUPLING 3. PUMP HOUSING 4. HYDRAULIC RESERVOIR 5. SCREW 6. DRAIN PLUG AND O-RING 7. CLAMPS AND O-RING 8. MAIN VALVE BLOCK 9. PROPORTIONAL VALVE (LOWERING) 10. LIFT VALVE AND COIL 11. BREATHER/FILLER CAP AND ELBOW 12. SCREW 13. PLUG 14. AUXILIARY VALVE BLOCK 15. VALVE (TILT) 16. VALVE (SIDESHIFT) 17. TUBE 18. PRESSURE RELIEF VALVE 19. CHECK VALVE 20. CAPSCREWS Figure 7. Lift Pump and Motor Assembly With Auxiliary (W25/30/40ZC) 10

15 2000 SRM 1025 Lift Pump and Motor Repair DISASSEMBLE Remove Reservoir 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 Disposal of lubricants and fluids must meet local environmental regulations. 6. Pour oil from reservoir into a container suitable for disposal. 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. Remove Pump Motor 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. 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 Separate reservoir adaptor plate from pump by removing attaching hardware (W20/30ZR and W30/40ZA only). 3. Tag and identify each tube and their corresponding locations. 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. 11

16 Lift Pump and Motor Repair 2000 SRM 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. ASSEMBLE Assemble 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. 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 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 fourscrewsandtorqueto22n m(16lbfft). 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). 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. 4. Tighten the capscrews to 8 N m (71 lbf in). Install Reservoir to Pump 1. Place reservoir in an upright position on the floor. 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 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. 12

17 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. SeeTable1. 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 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. 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 Remove the drive unit compartment cover. On W25/30/40ZC lift trucks, also remove the hydraulic compartment cover. 6. Discharge the capacitor. See Special Precautions. 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. 8. Remove the locking screw from the control wiring plug. Disconnect the plug from the coil. 9. Remove the retaining clip and washer. 10. Slidethecoiloffofthevalve. 11. 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. 3. Lubricate the valve cartridge threads and O-rings with clean hydraulic oil. 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. 13

18 Valve Repair 2000 SRM Operate each hydraulic function several times to purge the air from the hydraulic circuit. 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. 13. Check hydraulic oil level in reservoir and fill to proper level. See Table 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 Remove 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 Remove the drive unit compartment cover. On W25/30/40ZC lift trucks, also remove the hydraulic compartment cover. 6. Discharge the capacitor. See Special Precautions. 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. 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. 10. Remove the nut and slide the front coil off the valve. 11. Removethespacerandtherearcoil. 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. 3. Lubricate the valve cartridge threads and O-rings with clean hydraulic oil. 4. Installthevalvecartridgeandtorqueto34N 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. 14

19 2000 SRM 1025 Valve Repair 15. Test lift truck by lifting and lowering a load several times. Check for leaks. 16. Install the drive unit compartment cover. If necessary, install the hydraulic unit compartment cover. LIFT VALVE Remove 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 Remove the drive unit compartment cover. On W25/30/40ZC lift trucks, also remove the hydraulic compartment cover. 6. Discharge the capacitor. See Special Precautions. WARNING Hydraulic oil hoses and lines may be under high pressure. Hydraulic oil can be injected into the body bypressure.topreventpossible 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. 8. Remove the locking screw from the control wiring plug. Disconnect the plug from the coil. 9. Remove the nut from the top of the coil. 10. Remove the upper O-ring and slide the coil off the valve cartridge. 11. Remove the lower O-ring from the valve cartridge. 12. Remove the valve cartridge. Install 1. Verify that the valve cartridge and coil O-rings are not damaged. Replace as needed. 2. Verify that the valve cartridge and valve block are clean and not damaged. 3. Lubricate the valve cartridge threads and O-rings with clean hydraulic oil. 4. Install the valve cartridge and torque to 27 N m (20 lbf ft). 5. Install the lower O-ring over the valve cartridge. 6. Slide the coil over the valve cartridge with the lettering out towards the coil retainer. 7. Install the second O-ring over the valve cartridge. 8. Install the nut and torque to 7 N m (60 lbf in). 9. Connect the control wiring plug to the coils. 10. Install the locking screw into the coil plug. 11. Connect any power wires and hydraulic hoses previously disconnected. 12. Connect battery and turn key switch to ON position. 13. Operate each hydraulic function several times to purge the air from the hydraulic circuit. 14. 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. 15. Check hydraulic oil level in reservoir and fill to proper level. See Table Test lift truck by lifting and lowering a load several times. Check for leaks. 17. Install the drive unit compartment cover. If necessary, install the hydraulic unit compartment cover. 15

20 Valve Repair 2000 SRM 1025 COUNTERBALANCE VALVE W20/30ZR Remove 1. Move the lift truck to a safe and level area. 2. Lower the forks completely and extend the forks completely. Tilt the forks down until they contact the floor. 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 Remove drive unit compartment cover. 6. Discharge the capacitor. See Special Precautions. WARNING There are pinch points on the reach carriage that can cause an injury. Use clamps and blocks to stop the scissor arms from moving. 7. Install clamps and blocks (on both sides) between the load bearings and the bottom of the rear frame of the reach assembly to keep the forks from retracting. See Figure 8. 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. 8. Loosen both hydraulic hose fittings on the bottom of the valve block to relieve pressure from the tilt circuit. See Figure 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. 1. REAR FRAME OF THE REACH ASSEMBLY 2. LOAD BEARING 3. WOOD BLOCK 4. CLAMP Figure 8. Typical Blocks and Clamps Installation 3. Lubricate the valve cartridge threads and O-rings with clean hydraulic oil. 4. Installthevalvecartridgeandtorqueto47N m (35 lbf ft). 5. Tighten the hydraulic hose fittings. 6. Remove the clamps and blocks. 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 hydraulic oil level in reservoir and fill to proper level. See Table Test lift truck by lifting and lowering a load several times. Check for leaks. 11. Install the drive unit compartment cover. 16

21 2000 SRM 1025 Valve Repair 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. 8. Loosen one tilt cylinder hose fitting at the valve block to relieve any remaining pressure from the tilt circuit. See (Figure 10, Item 1). 1. VALVE BLOCK 2. HYDRAULIC HOSE FITTING 3. COUNTERBALANCE VALVE Figure 9. Counter Balance Valve and Valve Block W25/30/40ZC Remove 1. Move lift truck to a safe and level area. 2. Lower forks completely to relieve pressure from the hydraulic circuit. 3. Position the mast vertical and secure the positioning with an overhead lifting device to prevent the mast from tilting forward/backward. 4. Turn key switch to OFF position and disconnect battery. 5. Block load wheels to prevent lift truck from moving. Refer to Periodic Maintenance 8000 SRM Remove the drive unit compartment cover and the hydraulic unit compartment cover. 7. Discharge the capacitor. See Special Precautions. 1. HYDRAULIC HOSE FITTING 2. VALVE BLOCK 3. COUNTERBALANCE VALVE Figure 10. Counterbalance Valve and Valve Block 9. Tighten the hydraulic hose fitting. 10. Slowly loosen and 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. 3. Lubricate the valve cartridge threads and O-rings with clean hydraulic oil. 4. Install the valve cartridge and torque to 47 N m (35 lbf ft). 17

22 Valve Repair 2000 SRM Disconnect the overhead lifting device from the mast. 6. Connect battery and turn key switch to ON position. 7. Operate each hydraulic function several times to purge the air from the hydraulic circuit. 8. 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. Check hydraulic oil level in reservoir and fill to proper level. See Table Test lift truck by lifting and lowering a load several times. Check for leaks. 11. Install the drive unit compartment and the hydraulic unit compartment cover. RELIEF VALVE AND CHECK VALVE NOTE: The relief valve and check valve are located on the lift pump assembly. Remove 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 Remove the drive unit compartment cover. On W25/30/40ZC lift trucks, also remove the hydraulic compartment cover. 6. Discharge the capacitor. See Special Precautions. 7. If necessary, tag and disconnect the power wires to obtain adequate clearance to tilt the lift pump and motor assembly away from the frame. 8. If necessary, remove the two nuts and washers attaching the mounting bracket to the isolators and tilt the lift pump and motor assembly away from the frame. 9. Slowly loosen the relief valve cartridge to relieve pressure. 10. Remove the relief valve cartridge. 11. If necessary, remove the check valve cartridge using a 90 mm (3.5 in.) long M8 bolt. Thread the bolt into the cartridge to pull it from the housing. Install 1. Verify that the O-rings on the valve cartridges are not damaged. Replace as needed. 2. Verify that the valve cartridges and pump housing are clean and not damaged. 3. Lubricate the relief valve cartridge threads and the O-rings on both valve cartridges with clean hydraulic oil. 4. If removed, install the check valve cartridge. 5. Install the relief valve cartridge and torque to 32 N m (23.5 lbf ft). 6. If removed, install the two nuts and washers connecting the mounting bracket and isolators. Torque the nuts to 15 N m (11 lbf ft). 7. If removed, 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). 8. Connect battery and turn key switch to ON position. 9. Operate each hydraulic function several times to purge the air from the hydraulic circuit. 10. 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. 11. Check hydraulic oil level in reservoir and fill to proper level. See Table Verify that the relief valve settings are correct. See Relief Valve Adjustment. PILOT OPERATED CHECK VALVE W20/30ZR NOTE: The pilot operated check valve is located on the mast. 18

23 2000 SRM 1025 Valve Repair Remove 1. Move the lift truck to a safe and level area. 2. Lower the forks completely and extend the forks completely. 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 Remove drive unit compartment cover. 6. Discharge the capacitor. See Special Precautions. WARNING There are pinch points on the reach carriage that can cause an injury. Use clamps and blocks to stop the scissor arms from moving. 7. Install clamps and blocks (on both sides) between the load bearings and the bottom of the rear frame of thereachassemblytokeepthe forks from retracting. See Figure 8. WARNING Hydraulic oil hoses and lines may be under high pressure. Hydraulic oil can be injected intothebodybypressure.topreventpossible injury, shield yourself from any escaping oil. Wrap a rag around the fitting and loosen the fitting and loosen the connection slowly. 8. Loosen one hydraulic hose fitting on the lower side of the valve block to relieve pressure. See (Figure 11, Item 1). 9. Remove the check valve cartridge. Install 1. Verify that the valve cartridge O-rings are not damaged. Replace as needed. 2. Verify that the valve cartridge and valve block are clean and not damaged. 3. Lubricate the check valve cartridge threads and O-rings with clean hydraulic oil. 1. HYDRAULIC HOSE FITTING 2. VALVE BLOCK 3. CHECK VALVE Figure 11. Pilot Operated Check Valve and Valve Block 4. Install the valve cartridge and torque to 27 N m (20 lbf ft). 5. Tighten the hydraulic hose fitting. 6. Remove the clamps and blocks. 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 Test lift truck by lifting and lowering a load several times. Check for leaks. 12. Install the drive unit compartment cover. SELECTOR VALVES: REACH, TILT, AND SIDESHIFT W20/30ZR and W25/30/40ZC Remove 1. Move the lift truck to a safe and level area. 2. Lower the forks completely and extend the forks completely. 19

24 Valve Repair 2000 SRM 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 Remove the drive unit compartment cover. On W25/30/40ZC lift trucks, also remove the hydraulic compartment cover. 6. Discharge the capacitor. See Special Precautions. WARNING There are pinch points on the reach carriage that can cause an injury. Use clamps and blocks to stop the scissor arms from moving. 7. On W20/30ZR lift trucks, install clamps and blocks (on both sides) between the load bearings and the bottom of the rear frame of the reach assembly to keep the forks from retracting. See Figure Remove the locking screw from the control wiring plug. Disconnect the plug from the coil. See Figure Remove the nut and slide the coil off the valve cartridge. 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. 10. Loosen the selector valve cartridge slightly to relieve pressure. 11. Remove the valve cartridge. Install 1. Verify that the selector valve cartridge O-rings are not damaged. Replace as needed. 2. Verify that the selector valve cartridge and valve block are clean and not damaged. 1. VALVE BLOCK 2. REACH VALVE 3. HYDRAULIC HOSE FITTING 4. SIDESHIFT VALVE 5. TILT VALVE Figure 12. Selector Valves 3. Lubricate the selector valve cartridge threads and O-rings with clean hydraulic oil. 4. Install thevalvecartridgeandtorqueto34n m (25 lbf ft). 5. Slide the coil onto the valve cartridge with the lettering out towards the coil retainer. 6. Install the nut and torque to 7 N m (60 lbf in) 7. Connect the control wiring plug to the coil. 8. Install the locking screw into the coil plug. 9. Remove the clamps and blocks. 10. Connect battery and turn key switch to ON position. 11. Operate each hydraulic function several times to purge the air from the hydraulic circuit. 20

25 2000 SRM 1025 Relief Valve Adjustment 12. Checkthetopoftheliftcylindertodetermineif a buttonhead bleed screw is present. If a bleed screw is present, bleed the air from the hydraulic system. See Bleed Hydraulic System. 13. Check hydraulic oil level in reservoir and fill to proper level. See Table Test 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. WARNING Do not make repairs or adjustments unless you have both authorization and training. Incorrect repairs and adjustments can create dangerous operating conditions. Do not operate a lift truck that needs repairs. Report the need for repairs to your supervisor immediately. If repair is necessary, put a DO NOT OPERATE tag on the control handle. Remove the key from the key switch and disconnect the battery. 1. Check hydraulic oil level in reservoir when oil is at room temperature, forks fully lowered, and mast vertical. See Table 1 for the proper level. 2. Operate lift truck until hydraulic oil reaches operating temperature. 3. Lower forks completely to relieve pressure from hydraulic system. Remove key from switch and disconnect battery. 4. Remove the drive unit compartment cover. On W25/30/40ZC trucks, also remove the hydraulic compartment cover. 5. Turn key switch to OFF position and disconnect battery. 6. Block load wheels to prevent lift truck from moving. Refer to Periodic Maintenance 8000 SRM Relief Valve Adjustment 8. Disconnect the lift circuit pressure line at the pump. 9. Install a tee fitting and a pressure gauge of at least 21 MPa (3000 psi) capacity. 10. Connect the battery. 11. Verify the oil is at operating temperature. 12. Raise the forks completely and read the pressure gauge. NOTE: The pump may stop after a short period of time. Press the lower button briefly to reset the pump time-out circuit. 13. Correct reliefpressureis20mpa(2900psi). CAUTION To prevent damage to the relief valve adjustment screw, always loosen the locking nut prior to turning relief valve adjustment screw. 14. If the relief pressure is incorrect: a. Loosen the lock nut. b. Adjust the relief valve adjustment screw in small increments. Turn the adjustment screw clockwise to increase pressure. Turn the adjustment screw counterclockwise to decrease pressure. 7. Discharge the capacitor. See Special Precautions. WARNING Hydraulic oil hoses and lines may be under high pressure. Hydraulic oil can be injected intothebodybypressure.topreventpossible injury, shield yourself from any escaping oil. Wrap a rag around the fitting and loosen the fitting and loosen the connection slowly. c. Tighten the lock nut and torque to 19 N m (14 lbf ft). d. Recheck the relief pressure. e. Repeat as necessary, until the correct relief pressure is measured. 15. Lower forks completely to relieve pressure from hydraulic circuit. Turn key switch to OFF position. 21

26 Troubleshooting 2000 SRM Disconnect the battery. 17. Discharge the capacitor. See Special Precautions. 18. Removethepressuregaugeandtee. 19. Connect the lift circuit pressure line to the pump. 20. Operate each hydraulic function several times to purge the air from the hydraulic circuit. 21. 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. 22. Check hydraulic oil level in reservoir and fill to proper level. See Table Remove blocks from wheels. 24. Test lift truck by lifting and lowering a load several times. Check for leaks. 25. Install the drive unit compartment cover. If necessary, install the hydraulic unit compartment cover. Bleed Hydraulic System 1. Loosen buttonhead screw near top of cylinder. 2. Connect battery and turn key switch to ON position. 3. Briefly press and release Lift button repeatedly until hydraulic oil flows from bleed screw without bubbling. 4. Disconnect the battery. 5. Tighten the bleed screw. 6. Connect the battery. 7. Raise and lower forks to check for proper operation. Troubleshooting PROBLEM POSSIBLE CAUSE PROCEDURE OR ACTION Low hydraulic pressure. Pump is worn or damaged. Repair or install new pump. Relief valve needs adjustment. Adjust or replace relief valve. Hydraulic system relief valve opens frequently. Relief valve needs adjustment, or relief valve is defective. Restriction in the pressure side of the hydraulic system. Adjust or replace relief valve. Remove restriction or install new line. The pump noise is not normal. Oil in the hydraulic reservoir is low. Restriction in the inlet hose. Fill reservoir to correct level. Check for leaks. Remove restriction or install new line. 22

27 2000 SRM 1025 Troubleshooting PROBLEM POSSIBLE CAUSE PROCEDURE OR ACTION The pump noise is notnormal. (Cont.) Inlet fitting or inlet hose clamp is loose. The pump bearings or gears are damaged. The pump housing is damaged. Loose capscrews holding the pump housing together. Loose capscrews in the pump mounting. Pump motor is damaged or worn. Relief valve is stuck open. Tighten fitting. Install new hoses. Remove air from system. Repair or install new pump. Repair or replace pump housing. Tighten capscrews to specified torque. Tighten capscrews to specified torque. Check, repair, or install new parts as required. Clean, adjust, or replace the relief valve. The pump has lowoutput. The pump is worn. Check, repair, or install new parts as required. Seals or gaskets are damaged and cause leaks. The fitting at the pump leaks. Install new seals or gaskets. Tighten fittings. Install new parts as necessary. The pump has leaks. Fittings are loose or defective. Tighten fittings. Install new parts as necessary. Loose capscrews holding the pump housing together. Seals are defective. Tighten capscrews to specified torque. Install new seals or gaskets. Slow auxiliary functions Oil in the hydraulic reservoir is low. Fill reservoir to correct level. Check for leaks. Auxiliary valve is defective. Remove valve and inspect for contamination or damage to the cartridge. Replace if damaged. 23

28 Troubleshooting 2000 SRM 1025 PROBLEM POSSIBLE CAUSE PROCEDURE OR ACTION Lift pump and motor operates but the mast will not raise. The button is in the raise position. Oil in the hydraulic reservoir is low. Lift/lower coil is defective. Lift/lower cartridge is defective. Fill reservoir to correct level. Check for leaks. Measure the resistance on the coil and replace if not correct. EV EV Check for 0.5 to 0.8 amps of current at the coil of the cartridge. Check wiring for loose or bad connections. Check the valve cartridge for contamination and damage. Replace cartridge. 24

29 2000 SRM 1025 Hydraulic Diagrams and Schematics Hydraulic Diagrams and Schematics 1. LIFT PUMP AND MOTOR ASSEMBLY 2. PROPORTIONAL LOWERING VALVE 3. HOSE ASSEMBLY 4. FITTING 5. TUBE AND NUT ASSEMBLY 6. RELIEF VALVE Figure 13. Hydraulic Diagram W30/40ZA (Without Side-shift) 25