793C Off-Highway Truck Machine Systems Caterpillar

Disassembly Procedure

Start By:

1. Remove the service and parking brakes (rear) that are on the right or the left. Refer to Disassembly and Assembly, "Service and Parking Brake (Rear) - Remove" for the correct procedure.

1. Place the brake assembly on a suitable stand. The anchor should be facing downward. The service brake weighs approximately 854 kg (1882.7 lb).
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   Illustration 1	g00466169

2. Remove twelve bolts (1) and the washers that are identified in the picture from the service brake assembly.
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   Illustration 2	g00466170

3. Turn over the service brake assembly. Remove 55 bolts (2) and the 55 washers that hold anchor (3) in place.

4. Loosen eight nuts (4) between one-half and one turn at a time in order to release the tension of the compression spring.
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   Illustration 3	g00466436

5. Use a suitable lifting device to remove anchor (3) from the brake assembly. Anchor (3) weighs approximately 206 kg (454.2 lb).

6. Remove eight nuts (4) from anchor (3).
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   Illustration 4	g00466437

7. Turn over anchor (3). Place anchor (3) on a suitable stand. Piston (5) should be facing upward.
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   Illustration 5	g00466439

8. Install two 3/8 inch - 16 NC forcing screws in piston (5). Evenly tighten forcing screws in order to compress the guide springs.
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   Illustration 6	g00466441

9. Install four pins in four guides (7) while the forcing screws are removed.

10. Remove the forcing screws from the service brake.
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    Illustration 7	g00466443

11. Press down piston (5). Remove four pins (8) from four guides (7).
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    Illustration 8	g00466445

12. Use Tool (A) and a suitable lifting device to remove piston (5). The weight of piston (5) is 83 kg (183.0 lb).
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    Illustration 9	g00466468

13. Remove two ring seals (9). Remove two ring seals (10) from piston (5).
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    Illustration 10	g00439491

14. Loosen nuts (11) by one-half turn at a time in order to release the tension of the compression spring.
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    Illustration 11	g00439493

15. Use Tool (A) and a suitable lifting device in order to remove piston (13) and housing (12) as a unit. The combined weight of piston (13) and housing (12) is approximately 112 kg (246.9 lb).

16. Remove nuts (11) from housing (12).

17. Separate housing (12) and piston (13).
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    Illustration 12	g00439495

18. Remove two seal rings (14). Remove two seal rings (15) from housing (12).
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    Illustration 13	g00439583

19. Remove seal ring (16) from piston (13).
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    Illustration 14	g00439623

20. Use Tool (B) to compress guide spring (6) (not shown). Remove the pin, guide (7), and guide spring (6) from piston (13). Repeat this step for the remaining three pins, guides (7), and guide springs (6).
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    Illustration 15	g00466471

    Note: There are four springs (17) at location (X) that do not have inner springs (18). Use identification marks on the springs for installation purposes.

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    Illustration 16	g00466472

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    Illustration 17	g00466473

21. Remove three O-ring seals (19), (20), and (21) from anchor (3).

22. Remove 12 studs (22) from anchor (3).
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    Illustration 18	g00466478

23. Remove four plugs (23) and the four O-rings from anchor (3).

24. Remove 21 studs (25) and 47 studs (24) from anchor (3).
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    Illustration 19	g00440245

25. Remove eight studs (26) from ring (29).
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    Illustration 20	g00440247

26. Remove two dampers (27), the 15 friction discs, and 14 plates (28) from the service brake assembly.
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    Illustration 21	g00440249

27. Turn over ring (29) and plate (30). The weight of ring (29) and plate (30) is 200 kg (440.9 lb). Remove 44 bolts (31) and plate (30) from ring (29). The weight of plate (30) is 110 kg (242.5 lb).
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    Illustration 22	g00440250

28. Remove O-ring seal (32) from ring (29).