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. Wiping cloths or rags should not be used to dry parts. Lint may be deposited on the parts which may cause later trouble.

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

2. Lubricate all of the O-ring seals lightly with the lubricant that is being sealed.
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   Illustration 1	g00527155

3. Install two seals (27) onto plate (21).
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   Illustration 2	g00527154

4. Install two nuts (26) onto cylinder tube (19).

5. Install two seals (25) onto cylinder tube (19).
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   Illustration 3	g00527153

6. Install seal (24) onto body (20).

7. Install valve (22) and rod (9) into body (20).

8. Use Tool (A) in order to install retaining ring (23) onto body (20).
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   Illustration 4	g00527131

9. Install cylinder tube (19) onto plate (21). Cylinder tube (19) must bottom out in plate (21). Tighten cylinder tube (19) to a torque of 14 N·m (123.9 lb in).

10. Install piston body (20) and rod (9) into cylinder tube (19) as a unit.
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    Illustration 5	g00527129

11. Install purge screw (17) onto end cap (18). Tighten purge screw (17) to a torque of 14 ± 3 N·m (123.9 ± 26.6 lb in).

12. Install end cap (18) onto cylinder tube (19). Adjust end cap (18) within one revolution of bottoming out on cylinder tube (19). Tighten end cap (18) to a torque of 14 N·m (123.9 lb in).

    Note: Purge screw (17) should be in-line with the reservoir port within 10 degrees.

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    Illustration 6	g00527128

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    Illustration 7	g00527126

13. Position seal (14) onto piston (15).

14. Install two O-ring seals (16) onto retaining ring (12). Install spring (13) onto retaining ring (12). Position retaining ring (12) onto piston (15).

15. Use six bolts (11) and the washers in order to install retaining ring (12) to piston (15). Tighten six bolts (11) to a torque of 10.5 ± .8 N·m (92.9 ± 7.1 lb in).
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    Illustration 8	g00527123

16. Install spring (10) and piston assembly (8) onto rod (9).
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    Illustration 9	g00527277

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    Illustration 10	g00527122

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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.

17. Position cylinder assembly (1), piston assembly (8) and spring (10) into a suitable bench vise (not shown). Use the bench vise (not shown) in order to compress spring (10).

18. Install locknut (6) onto rod (9). Tighten locknut (6) to a torque of 145.5 ± 37.5 N·m (107.32 ± 27.66 lb ft).

19. Install O-ring seal (7) onto indicator rod (4). Install indicator rod (4) into cylinder assembly (1).

20. Install limit switch (5) and the O-ring seal into cylinder assembly (1). Tighten limit switch (5) to a torque of 7.5 ± 2.5 N·m (66.38 ± 22.13 lb in).
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    Illustration 11	g00527121

21. Use eight nuts (2) in order to install cylinder assembly (3) to cylinder assembly (1). Tighten eight nuts (2) to a torque of 14 ± 3 N·m (123.91 ± 26.55 lb in).

End By:

1. Install the front air/hydraulic cylinder or the rear air/hydraulic cylinders for the brakes. Refer to either Disassembly and Assembly, "Air/Hydraulic Cylinder (Front Brake) - Install" or refer to Disassembly and Assembly, "Air/Hydraulic Cylinder - Install".