69D and 769D Off-Highway Trucks and 771D Quarry Truck Machine Systems Caterpillar

Disassembly Procedure

Start By:

1. Remove the parking and secondary brake valve. Refer to Disassembly and Assembly, "Brake Valve (Parking and Secondary) - Remove".

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Illustration 1	g00485180

1. Remove check valve (1) and connector (3) from brake valve (2).
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   Illustration 2	g00485264

2. Remove O-ring seal (4) from check valve (1).
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   Illustration 3	g00485266

3. Remove two locking bolts (5) and the hard washers. Remove air cylinder (6) and the O-ring seal from brake valve (2).
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   Illustration 4	g00485320

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   Illustration 5	g00572404

4. Use a suitable screwdriver (not shown) to remove snap ring (7) from air cylinder (6).

5. Remove head (10) from air cylinder (6).

6. Remove seal (12) from head (10).

7. Remove piston (9) from air cylinder (6).

8. Remove seal (8) and seal (11) from piston (9).
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   Illustration 6	g00572414

9. Remove lip seal (13) from head (10).
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   Illustration 7	g00485422

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   Illustration 8	g00485423

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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.

10. Remove O-ring plug (14), the O-ring seal, spring (17) and four shims (16) from brake valve (2).

11. Remove spool (15) from brake valve (2).
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    Illustration 9	g00607227

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    Illustration 10	g00573551

12. Remove relief valve (18) and O-ring plug (19) from brake valve (2).
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    Illustration 11	g00573552

13. Remove cap (20), gasket (21), nut (22) and gasket (23) from relief valve (18).

14. Remove O-ring seal (24), (25) and (26) from relief valve (18).
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    Illustration 12	g00485460

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    Illustration 13	g00485484

15. Remove check valve (27) from brake valve (2).
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    Illustration 14	g00573596

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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.

16. Remove O-ring plug (34), O-ring seal (32), spring (31), dowel (33) and valve (30) from check valve (27).

17. Remove O-ring seal (28) and (29) from check valve (27).