776D, 777D and 777D HAA Off-Highway Trucks Machine Systems Caterpillar

Assembly Procedure

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Illustration 1	g00486480

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Improper assembly of parts that are spring loaded can cause bodily injury. To prevent possible injury, follow the established assembly procedure and wear protective equipment.

1. Install valve (72), shims (73), spring (74), O-ring (75) and plug (76) into body (65) .

   Note: To determine the correct amount of shims (73) that are required, refer to Hydraulic System, Systems Operation, Testing and Adjusting, "Relief Valve (Brake Oil Cooler) - Test and Adjust".

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Illustration 2	g00486006

2. Install two O-ring seals (71) onto body (65) .

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Illustration 3	g00485979

3. Install O-ring (68), spring (69) and valve (70) onto plug assembly (64) .

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Illustration 4	g00485970

4. Install plug assembly (64) into the control valve.

5. Install body (65) into the control valve.

6. Install all of the remaining O-ring plugs (66) .

7. Install spool (67) into the control valve.

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Illustration 5	g00485964

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Illustration 6	g00485958

8. Install O-ring seal (62) and piston (63) onto plug (59) .

9. Install plug (59) and piston (63) into adapter (58) .

10. Install O-ring seal (60). Install O-ring seal (61) .

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Illustration 7	g00485944

11. Install O-ring seal (56) onto solenoid assembly (53) .

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Illustration 8	g00485941

12. Install O-ring seal (55) onto O-ring plug (52) .

13. Repeat Step 12 for the remaining O-ring plug (52) .

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Illustration 9	g00485781

14. Position solenoid assembly (53) on hydraulic actuator (40), as shown. Install four socket head bolts (54). Install two O-ring plugs (52) .

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Illustration 10	g00485780

15. Install spring (46) and control spool (47) into hydraulic actuator (40). Install three springs (48), (49) and (50). Install retainer (51) .

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Illustration 11	g00485760

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Improper assembly of parts that are spring loaded can cause bodily injury. To prevent possible injury, follow the established assembly procedure and wear protective equipment.

16. Position hydraulic actuator (40) in a suitable hydraulic press. Press the retainer in order to compress the spring. Use Tooling (A) in order to install retaining ring (45) .

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Illustration 12	g00485740

17. Install O-ring seal (44) on hydraulic actuator (40). Install two O-ring seals (42) and (43) .

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Illustration 13	g00485954

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Illustration 14	g00485720

18. Position adapter (58), hydraulic actuator (40) and clip (41), as shown. Install two bolts (39) .

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Illustration 15	g00485951

19. Repeat Steps 11 through 18 for the remaining hydraulic actuator (57) .

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Illustration 16	g00485682

20. Install valve (35) and screen (36) into main relief dump spool valve (32). Use Tooling (B) (not shown) to install retaining ring (37) into main relief dump spool valve (32). Position valve disc (38) into main relief dump spool valve (32) .

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Illustration 17	g00485629

21. Install two O-ring seals (34). Install O-ring seal (33) into main relief dump spool valve (32) .

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Illustration 18	g00485586

22. Position main relief dump spool valve (32) on the control valve (hoist), as shown. Install two bolts (28) .

23. Install two O-ring seals (29) onto the main relief dump spool valve. Install O-ring seal (31). Install spring (30) .

    Note: Steps 24 through 28 are for the assembly of the high pressure relief valve.

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Illustration 19	g00713697

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Possible injury can result when removing nut, retainer and hold down spring. Spring force will be released when nut and retainer are removed. Be prepared to hold the retainer as the nut is loosened.

24. Install O-ring seal (24) and retainer (25) into body (20) .

25. Install two O-ring seals (21) and (23) onto body (20) .

26. Install valve (22) and spring (27) into body (20) .

27. Install O-ring seal (26) into body (20) .

28. Install orifice nut (19) and the washer. Install retainer assembly (18) .

    Note: Steps 29 through 33 are for the assembly of the low pressure relief valve.

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Illustration 20	g00713696

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Possible injury can result when removing nut, retainer and hold down spring. Spring force will be released when nut and retainer are removed. Be prepared to hold the retainer as the nut is loosened.

29. Install O-ring seal (14) and retainer (15) into body (10) .

30. Install two O-ring seals (11) and (13) onto body (10) .

31. Install valve (12) and spring (17) into body (10) .

32. Install O-ring seal (16) into body (20) .

33. Install orifice nut (9) and the washer. Install retainer assembly (8) .

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Illustration 21	g00485127

34. Install O-ring seal (6) and spring (7) on O-ring plug (3) .

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Illustration 22	g00485125

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Improper assembly of parts that are spring loaded can cause bodily injury. To prevent possible injury, follow the established assembly procedure and wear protective equipment.

35. Install O-ring plug (3) into dual stage signal spool valve (2). Install high pressure relief valve (5) and low pressure relief valve (4) into the dual stage signal spool valve (2). Install all of the remaining O-ring plugs and O-ring seals.

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Illustration 23	g00485121

36. Position dual stage signal spool valve (2) on the hoist control valve, as shown. Install three bolts (1) on the hoist control valve.

End By: Install the hoist control valve. Refer to Disassembly and Assembly, "Control Valve (Hoist) - Install".