988G Wheel Loader Machine Systems Caterpillar

Disassembly Procedure

Start By:

1. Remove the fan drive pump. Refer to Disassembly and Assembly, "Piston Pump (Hydraulic Fan) - Remove".

Show/hide table

NOTICE
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat products. Dispose of all fluids according to local regulations and mandates.

1. Be sure that the outside of the fan drive pump is thoroughly clean prior to disassembly.
   Show/hide table

   Illustration 1	g00670363

2. In order to protect the shaft seal, use an adhesive tape to cover the drive shaft.
   Show/hide table

   Illustration 2	g00669721

3. Remove four bolts (2) and pressure and flow compensator valve (1) from fan drive pump (3).
   Show/hide table

   Illustration 3	g00670188

4. Remove three O-ring seals (4) from compensator valve (1).
   Show/hide table

   Illustration 4	g00670190

5. Remove plug (5) from compensator valve (1). Repeat this procedure for the opposite side.
   Show/hide table

   Illustration 5	g00670191

6. Remove O-ring seal (6) from plug (5).
   Show/hide table

   Illustration 6	g00670192

7. Remove plug (7) from compensator valve (1).
   Show/hide table

   Illustration 7	g00670195

8. Remove O-ring seal (8) from plug (7).

9. Remove plate (9), spring (10), spring (11), and guide (12) from compensator valve (1).
   Show/hide table

   Illustration 8	g00670197

10. Remove plug (13) from compensator valve (1).
    Show/hide table

    Illustration 9	g00670198

11. Remove spool (14) from compensator valve (1).

12. Remove spacer (15) from plug (13).
    Show/hide table

    Illustration 10	g00670199

13. Remove plug (16) from compensator valve (1).
    Show/hide table

    Illustration 11	g00670201

14. Remove O-ring seal (17) from plug (16).

15. Remove plate (18), spring (19), spring (20) and guide (21) from compensator valve (1).
    Show/hide table

    Illustration 12	g00670202

16. Remove plug (22) from compensator valve (1).
    Show/hide table

    Illustration 13	g00670203

17. Remove spool (23) from compensator valve (1).

18. Remove spacer (24) from plug (22).
    Show/hide table

    Illustration 14	g00669722

19. Place fan drive pump (2) on suitable wood blocks, as shown.

20. Remove four bolts (25) from head assembly (26).
    Show/hide table

    Illustration 15	g00669723

21. Remove head assembly (26) from pump body (27).
    Show/hide table

    Illustration 16	g00669727

22. Remove O-ring seal (28) and port plate (29) from head assembly (26).
    Show/hide table

    Illustration 17	g00669728

23. Remove bearing cup (30).
    Show/hide table

    Illustration 18	g00669729

24. Remove O-ring (31).
    Show/hide table

    Illustration 19	g00669730

25. Remove bearing (32) from the shaft.
    Show/hide table

    Illustration 20	g00669731

26. Remove adjustment shim (33).
    Show/hide table

    Illustration 21	g00669732

27. Remove plug (34).
    Show/hide table

    Illustration 22	g00669738

28. Remove O-ring seal (35) from plug (34).
    Show/hide table

    Illustration 23	g00669742

29. Carefully place the pump in a horizontal position.

30. Remove rotary group (36).
    Show/hide table

    Illustration 24	g00669741

31. Remove piston assembly (37) from barrel assembly (38).
    Show/hide table

    Illustration 25	g00669743

32. Remove retaining ball (39) from barrel assembly (38).
    Show/hide table

    Illustration 26	g00669744

    Show/hide table

    Illustration 27	g00669745

    Show/hide table

    Sudden release of spring force can cause injury. To prevent the possibility of injury, follow the procedure to relieve the spring pressure.

    Note: There is spring force against retaining ring (43). When retaining ring (43) is removed, the spring force will be released. Removal of the internal components in barrel (38) should be performed in a press. This is done in order to retain spring (42) and retaining ring (43).

33. Use a suitable press and Tooling (A) in order to compress the spring in barrel assembly (38).

34. Use Tooling (B) in order to remove retaining ring (43) from the barrel assembly (38).

35. Remove retaining ring (43), spring (42), guide (41), and pins (40) from the barrel.
    Show/hide table

    Illustration 28	g00670204

36. Move the swashplate up and down in order to remove the control piston (44).
    Show/hide table

    Illustration 29	g00670205

    Note: In order to release the piston rod (45) from the swashplate, lift the swashplate a little and move the piston rod sideways.

37. Remove piston rod (45).
    Show/hide table

    Illustration 30	g00670206

38. Remove the swashplate (46).
    Show/hide table

    Illustration 31	g00670207

39. Remove spring (47).
    Show/hide table

    Illustration 32	g00670223

40. Remove two swashplate bearings (48).
    Show/hide table

    Illustration 33	g00670298

41. Remove shaft assembly (49).
    Show/hide table

    Illustration 34	g00670301

    Show/hide table

    Illustration 35	g00670302

42. Remove snap ring (50).

43. Use Tooling (A) in order to remove seal (51).
    Show/hide table

    Illustration 36	g00670360

44. Remove two plugs (52) from pump body (27). Inspect the O-ring seals on the plugs. Replace the O-ring seals, if necessary.
    Show/hide table

    Illustration 37	g00670361

45. Remove bearing cup (53) from pump body (27).
    Show/hide table

    Illustration 38	g00670362

46. Use Tooling (C) and a suitable press in order to remove bearing (54) from shaft (49).