824H Wheel Dozer, 825H Soil Compactor and 826H Landfill Compactor Machine Systems Caterpillar

Disassembly Procedure

Start By:

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

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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 piston pump is thoroughly clean prior to disassembly.
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   Illustration 1	g00670363

2. In order to protect the shaft seal, use an adhesive tape to cover the drive shaft.
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   Illustration 2	g00669721

3. Remove four bolts (2) and pressure and flow compensator valve (1) from fan drive pump (3).
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   Illustration 3	g00670188

4. Remove three O-ring seals (4) from compensator valve (1).
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   Illustration 4	g00670190

5. Remove plug (5) from compensator valve (1). Repeat for opposite side.
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   Illustration 5	g00670191

6. Remove O-ring seal (6) from plug (5).
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   Illustration 6	g00670192

7. Remove plug (7) from compensator valve (1).
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   Illustration 7	g00670195

8. Remove O-ring seal (8) from plug (7). Remove plate (9), spring (10), spring (11), and guide (12) from compensator valve (1).
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   Illustration 8	g00670197

9. Remove plug (13) from compensator valve (1).
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   Illustration 9	g00670198

10. Remove spool (14) from compensator valve (1). Remove spacer (15) from plug (13).
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    Illustration 10	g00670199

11. Remove plug (16) from compensator valve (1).
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    Illustration 11	g00670201

12. Remove O-ring seal (17) from plug (16). Remove plate (18), spring (19), spring (20) and guide (21) from compensator valve (1).
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    Illustration 12	g00670202

13. Remove plug (22) from compensator valve (1).
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    Illustration 13	g00670203

14. Remove spool (23) from compensator valve (1). Remove spacer (24) from plug (22).
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    Illustration 14	g00669722

15. Place fan drive pump (2) on wood blocks, as shown. Remove four bolts (25) from head assembly (26).
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    Illustration 15	g00669723

16. Remove head assembly (26) from pump body (27).
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    Illustration 16	g00669727

17. Remove O-ring seal (28) and port plate (29) from head assembly (26).
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    Illustration 17	g00669728

18. Remove bearing cup (30).
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    Illustration 18	g00669729

19. Remove O-ring (31).
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    Illustration 19	g00669730

20. Remove bearing (32) from the shaft.
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    Illustration 20	g00669731

21. Remove adjustment shim (33).
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    Illustration 21	g00669732

22. Remove plug (34).
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    Illustration 22	g00669738

23. Remove O-ring seal (35) from plug (34).
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    Illustration 23	g00669742

24. Carefully place the pump in a horizontal position.

25. Remove rotary group (36).
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    Illustration 24	g00669741

26. Remove piston assembly (37) from barrel assembly (38).
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    Illustration 25	g00669743

27. Remove retaining ball (39) from barrel assembly (38).
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    Illustration 26	g00669744

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    Illustration 27	g00669745

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    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).

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

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

30. Remove retaining ring (43), spring (42), guide (41), and pins (40) from the barrel.
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    Illustration 28	g00670204

31. Move the swashplate up and down in order to remove the control piston (44).
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    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.

32. Remove piston rod (45).
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    Illustration 30	g00670206

33. Remove the swashplate (46).
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    Illustration 31	g00670207

34. Remove spring (47).
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    Illustration 32	g00670223

35. Remove two swashplate bearings (48).
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    Illustration 33	g00670298

36. Remove shaft assembly (49).
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    Illustration 34	g00670301

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    Illustration 35	g00670302

37. Remove snap ring (50).

38. Use Tooling (A) to remove seal (51).
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    Illustration 36	g00670360

39. Remove two plugs (52) from pump body (27). Inspect the O-ring seals on the plugs. Replace the O-ring seals, if necessary.
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    Illustration 37	g00670361

40. Remove bearing cup (53) from pump body (27).
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    Illustration 38	g00670362

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