784C and 785C Off-Highway Trucks Machine Systems Caterpillar

Assembly Procedure

Note: Cleanliness is an important factor. Before the assembly procedure, all parts should be thoroughly cleaned in cleaning fluid. Allow the parts to air dry. Do not use Wiping cloths or rags to dry parts. Lint may be deposited on the parts which may cause later trouble.

1. Check all the O-ring seals and the components for wear or damage. Replace the components, if necessary.

2. Lubricate all the O-ring seals lightly with the lubricant that is being sealed.
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   Illustration 1	g06356511

3. If necessary, use Tooling (D) (not shown) to install five taperlock studs (33) to plate (30). Tighten taperlock studs (33) to a torque of 110 ± 20 N·m (80 ± 15 lb ft).

4. Use Tooling (F) to install Duo-cone seal (34) onto plate (30).
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   Illustration 2	g00529646

5. Install O-ring seal (32) to ring (23).
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   Illustration 3	g06373432

6. Attach Tooling (B) and a suitable lifting device to ring (23). Install ring (23) to plate (21). The weight of ring (23) is approximately 67 kg (148 lb).

7. Install bolts (31) and the washers that hold plate (30) to ring (23). Tighten bolts (31) to a torque of 310 ± 25 N·m (230 ± 18 lb ft).
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   Illustration 4	g06373440

8. Use Tooling (G) (not shown) to install Duo-cone seal (29) to brake hub (27).
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   Illustration 5	g00529639

9. Attach a suitable lifting device to brake hub (27), as shown. Install brake hub (27) to ring (23). The weight of brake hub (27) is approximately 45 kg (99 lb).
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   Illustration 6	g00529615

   Note: Install damper assembly (26) so that the friction material is facing toward the plate.

10. Install damper assembly (26) to ring (23).
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    Illustration 7	g00529611

    Note: Lubricate the friction discs with Tooling (K) during assembly.

11. Install friction disc (24) to ring (23).
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    Illustration 8	g00529614

12. Install outer plate (25) to ring (23).

13. Repeat Steps 11 and 12 for the remaining friction discs and outer plates.
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    Illustration 9	g00529609

    Note: Install damper assembly (22) so that the friction material is facing toward the piston.

14. Install damper assembly (22) to ring (23).
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    Illustration 10	g00529608

15. Apply Tooling (J) to the threads of taperlock studs (20), if the taperlock studs were removed. Use Tooling (D) to install taperlock studs (20). Tighten taperlock studs (20) to a torque of 260 ± 40 N·m (190 ± 30 lb ft).

16. Use Tooling (D) to install nine taperlock studs (21), if the taperlock studs were removed. Tighten taperlock studs (21) to a torque of 110 ± 20 N·m (80 ± 15 lb ft).

17. Install seals (18).

18. Install springs (19) to brake anchor (3) in the original positions.
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    Illustration 11	g00515928

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    Illustration 12	g00572198

19. Position spring (17) onto spring guide (5). Insert spring guide (5) into the piston.
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    Personal injury can result from being struck by parts propelled by a released spring force. Make sure to wear all necessary protective equipment. Follow the recommended procedure and use all recommended tooling to release the spring force.

20. Use Tooling (C) to compress spring (17). Install cotter pin (6) to spring guide (5).

21. Repeat Step 19 for the remaining spring guides (5).
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    Illustration 13	g00508902

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    Illustration 14	g00515724
    Example (A) illustrates incorrectly installed seal rings.

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    Illustration 15	g00515714
    Example (B) illustrates correctly installed seal rings.

    Note: Be sure that yellow side (A) of inside seal ring (B) is facing outward.

22. Install the seal and seal ring (16) to housing (13).

23. Install the seal and seal ring (15) to housing (13).
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    Illustration 16	g06356543

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    Illustration 17	g00516304

    Note: Be sure that the timing marks on piston (14) and housing (13) are in alignment, as shown.

24. Install Tooling (B) and a suitable lifting device to piston (14), as shown. Position piston (14) to housing (13). The weight of piston (14) is approximately 40 kg (88 lb).
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    Illustration 18	g06356526

25. Position piston (14) and housing (13) as a unit onto brake anchor (3). The weight of piston (14) and housing (13) is approximately 69 kg (152 lb).

26. Install nuts (12) and the remaining nuts. Tighten nuts (12) by one revolution before proceeding to the next nut. Tighten all the nuts in a star pattern to a final torque of 300 ± 15 N·m (220 ± 11 lb ft).
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    Illustration 19	g00508662

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    Illustration 20	g00515724
    Example (A) illustrates incorrectly installed seal rings.

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    Illustration 21	g00515714
    Example (B) illustrates correctly installed seal rings.

    Note: Be sure that yellow side (A) of inside seal ring (B) is facing outward.

27. Install two seal rings (11) to piston (8).

28. Install seal ring (9) to piston (8).
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    Illustration 22	g06356552

29. Install Tooling (B) and a suitable lifting device to piston (8). Install piston (8) to the brake anchor. The weight of piston (8) is approximately 42 kg (93 lb).
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    Illustration 23	g00515918

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    Illustration 24	g00508658

30. Use a soft faced hammer to drive the piston downward evenly until pin (7) can be installed into spring guide (5).

31. Repeat Step 30 for the remaining spring guides (5).
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    Illustration 25	g00508657

32. Install two 1/2 inch - 13 NC forcing screws (4) in the piston. Tighten the forcing screws evenly until there is approximately 25.4 mm (1 inch) between the two pistons.

33. Remove cotter pin (6) from the hole in spring guide (5).

34. Repeat Step 32 through Step 33 for the remaining three spring guides (5).
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    Illustration 26	g00508656

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    Illustration 27	g06373457

35. Remove two 1/2 inch - 13 NC forcing screws (4) from the piston.

36. Install Tooling (B) and a suitable lifting device to brake anchor (3) and position brake anchor (3), as shown. The weight of brake anchor (3) is approximately 112 kg (247 lb). Rotate brake anchor (3) upside-down.
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    Illustration 28	g00508655

37. Attach Tooling (A) and a suitable lifting device to brake anchor (3). Install brake anchor (3) to the ring. The weight of brake anchor (3) is approximately 112 kg (247 lb).

38. Install nuts (2) onto the taperlock studs.
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    Illustration 29	g00508649

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    Personal injury can result from being struck by parts propelled by a released spring force. Make sure to wear all necessary protective equipment. Follow the recommended procedure and use all recommended tooling to release the spring force.

39. Tighten five nuts (2) by one revolution before proceeding to the next nut. Tighten five nuts (2) in a star pattern to a final torque of 300 ± 15 N·m (220 ± 11 lb ft).
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    Illustration 30	g00508624

40. Install bolts (1) and the hard washers to the brake anchor. Tighten bolts (1) to a torque of 310 ± 25 N·m (230 ± 18 lb ft).
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    Illustration 31	g06373487

41. Attach Tooling (A) and Tooling (H) onto service and parking brake (1A). The weight of service and parking brake (1A) is approximately 508 kg (1120 lb). Rotate service and parking brake (1A) upside-down.
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    Illustration 32	g06373360

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    Illustration 33	g00515724
    Example (A) illustrates incorrectly installed seal rings.

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    Illustration 34	g00515714
    Example (B) illustrates correctly installed seal rings.

42. Install seal rings (28) to brake hub (27).

    Note: Be sure that yellow side (A) of inside seal ring (B) is facing outward.

End By:

1. Install the service and parking brake (front).