Work Steps
Work StepsCAUTION: Before proceeding, see Important Notes.* On certain models work steps 1-3 below are omitted and replaced by the steps found in "Important Notes." Important Notes
NOTE:
For application identification refer to "Steering : Power Steering Pump : Service and Repair : Overhaul Procedures : Application and ID" Application and ID
Disassembling:
1.* Screw down vent cap (35c). remove end cover (35d).
2.* Unscrew self-locking nut (35e) down from the stud bolt (35i). Remove plastic sleeve (35f) spring (35g) and filter set (35h).
3.* Unscrew bolts (35a. 4 bolts) in oil reservoir. Remove oil reservoir (35) and check O-ring (2g), replace if required.
4. Unscrew bolts (4b) in bearing flange (4) and remove pump housing (2).
5. Remove O-ring (4h) in bearing flange (4), check, replace if required.
Remove pressure plate (8).
Check seal (8a) and shaped wedge (8b), replace if required.
6. Remove cam insert (6) and Straight pins (6a). Check ground surface of pressure plate as well as the sliding surface of the vanes on the cam insert for scores and wear.
There must be no detectable scores on the sliding surface of the cam insert.
7. Remove locking ring (11a) from drive shaft (11). Replace locking ring. Detach rotor (7) from drive shaft (11) using a plastic hammer and remove all vanes (7a, 10 vanes).
Check the vanes (7a) in the grooves of the rotor (7): they must slide easily in the rotor. Check sliding surface of vanes on cam insert for wear. If required, repair power steering pump using the pump insert repair kit.
8. ZF: Withdraw drive shaft (11) from bearing flange (4).
Vickers/LUK: First carry out item 10 and remove drive shaft with bearing flange cap.
9 Check drive shaft for scores and wear at the bearing points (arrow). replace it required.
10. Unscrew bolts, 8 pieces M6, (4c) and remove bearing flange cap (4a).
Check radial seal ring (4d). replace it required.
11. Replace O-ring (5a).
ZF: Remove bearing sleeve (5f) and bearing seal (5g), check, replace it required.
Vickers/LUK: Detach snap ring from drive shaft, remove the additional built-in washer and bearing sleeve (5f) with bearing shell (5g).
12. Withdraw piston (5c) and piston springs (5d). Check piston and piston track for wear and damage, replace if required.
NOTE:
The piston must slide easily and without high spots in the housing. If this is not the case, the piston, piston springs, and piston support ring (5) must be replaced.
13. Remove spacer washer (5h) in the case of the ZF tandem pump.
14. Tap bearing flange housing (4) between two blocks of wood until the piston support ring (5) can be removed.
15. Replace O-rings (5b).
16. Replace O-ring (4f) and shaped wedge (4g) in housing.
Check radial seal ring (4e), replace if required.
NOTE:
If oil escapes from the servo circuit to the level Circuit or vice versa. the cause is in the radial seal ring (4e).
17. Withdraw radial seal ring (4e) with internal extractor 000 589 33 33 00. Check bronze bush in housing (4) for damage and wear, replace if required
18. Remove flow Control valve (2c) and Compression spring (2j) from pump housing (2).
CAUTION: When removing the locking ring (2a), ensure that the housing bore is not damaged.
19. Clamp flow control valve (2c) in the vise at an unground section and unscrew the valve screw (2e) of the pressure relief valve. Remove sealing cone (2f) and sealing cone compression spring (2d).
CAUTION: Check the ground surfaces of the flow control valve (2c) and the bore in the pump housing for wear and damage. If scores are found on the sliding surfaces, the tandem pump must be replaced.
20. Check both sealing cones (high pressure expansion hose, return pipe connection). Replace deformed sealing cone. For this step, cut a thread in the sealing cones a few thread turns deep with M7 Or M10. Withdraw the sealing cones from the housing with a M7 or M10 screw. Insert new sealing cones in housing and press into the housing by screwing the high pressure expansion hose or the return pipe into the housing.