Power Steering Pump: Service and Repair

REMOVAL

NOTE: Be sure to clean each joint of suction and discharge sides thoroughly before removal.





1. Remove suction hose from pump, then disconnect battery negative cable.
2. Remove oil tank with suction hose.
3. Remove union bolt. Then disconnect high pressure pipe from pump.

NOTE: As fluid flows out of disconnected joints, put a receptacle under joints or a plug to pipe.

4. Disconnect pressure switch lead wire at switch terminal.
5. Loosen related bolts and remove power steering belt.





6. Remove P/S pump mounting bolts.
7. Remove P/S pump.

NOTE: Plug each port of removed pump to prevent dust or any other foreign matter from entering.

DISASSEMBLY
1. Clean its exterior thoroughly.
2. With aluminum plates placed on vise first, grip pump body with it.





3. Remove suction connector bolt, suction connector and 0-ring from pump body.
4. Remove power steering pressure switch from pump body.
5. Remove plug, flow control spring and relief valve (flow control valve) from pump body.
6. Remove cover bolts, pump cover and 0-ring from pump body.
7. Remove snap ring from pump shaft.
8. Remove vanes from rotor.
9. Remove cam ring, rotor, side plate and 0-rings from pump body.
10. Pull out pulley from pump body.
11. Remove oil seal from pump body.

INSPECTION
Pump Body, Cover, Side Plate and Shaft





Check sliding surfaces of each part for wear and damage.
If any defect is found, replace pump assembly.

Cam Ring





Check vane sliding surface of cam ring for wear and damage.
If any defect is found, replace pump assembly.

Rotor and Vane





- Check sliding surfaces of rotor and vane for wear and damage.





- Check clearance between rotor and vane.

Clearance:
Standard 0.015 mm (0.0006 inch)
Limit 0.027 mm (0.0011 inch)

Replace pump assembly if any defect is found in above checks.

Relief Valve (Flow Control Valve) and Its Spring





- Check fluid passage of relief valve and orifice of connector for obstruction (clogged).
- Check sliding surface of relief valve for wear and damage.





- Check free length of relief valve spring.

Free length:
Standard 22.0 mm (0.866 inch)
Limit 19.0 mm (0.748 inch)

Replace if any defective is found.

ASSEMBLY
Reverse disassembly procedure for assembly, noting the following.





1. Apply grease to oil seal lip and apply power steering fluid to sliding surface of the shaft then insert pulley's shaft from oil seal side of the pump body.

"A": Grease 99000-25010





2. Apply power steering fluid to 0-rings and fit them to pump body.





3. Install side plate to pump body.

NOTE: Carefully align the dowel pins on the side plate at bolt hole as shown in figure.





4. Apply power steering fluid to sliding surface of rotor.
5. Install rotor to shaft, directing dot marked side of rotor facing up.
6. Install new snap ring to shaft, then make sure to fit snap into shaft groove securely.

NOTE: Never reuse the removed snap ring.





7. Apply power steering fluid to sliding surface of cam ring.
8. Install cam ring to pump body. The tapered end of cam ring should face the side plate.





9. Apply power steering fluid to each vane.
10. Install vanes (10 pieces) to rotor.





11. Apply power steering fluid to O-ring.
12. Install O-ring to pump body.





13. Apply power steering fluid to sliding surface of pump cover and rotor.
14. Match the dowel pins to the holes of the cover plate as shown and install pump cover to pump body.





15. Gradually tighten pump cover bolts to specified torque.

NOTE: After installing pump cover, check to make sure that shaft can be turned by hand.

Tightening Torque (a): 23 Nm (2.3 kg-m, 17.0 ft. lbs.)





16. Apply power steering fluid to 0-ring of pressure switch.
17. Install pressure switch to pump body.

Tightening Torque (b): 28 Nm (2.8 kg-m, 20.0 ft. lbs.)





18. Apply power steering fluid to relief valve (flow control valve).
19. Install relief valve (flow control valve) to pump body.
20. Install flow control spring.
21. Apply power steering fluid to 0-rings of plug.
22. Install 0-rings to plug.
23. Tighten plug to specified torque.

Tightening Torque (c): 60 Nm (6.0 kg-m, 43.5 ft. lbs.)





24. Apply power steering fluid to 0-ring of suction connector.
25. Install 0-ring to suction connector.





26. Install suction connector to pump body as shown in figure. Tighten suction connector bolts to specified torque.

Tightening Torque (d): 10 Nm (1.0 kg-m, 7.5 ft. lbs.)

INSTALLATION
Reverse removal procedure.

NOTE:
^ Fill specified power steering fluid after installation and bleed air without failure. (Refer to Air Bleeding Procedure)
^ For tightening torques, refer to structural diagram on previous page.

ADJUSTMENT
Refer to Drive Belt under Engine.