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 for 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	g00524944

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   Illustration 2	g00524943

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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.

3. Install spring (26) onto poppet (25). Install poppet (25) into plug (18).

4. Install piston (27) onto the end of poppet (25). Install nut (24) onto poppet (25).
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   Illustration 3	g00524942

5. Insert plug (18) into accumulator (1).
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   Illustration 4	g00525010

6. Fold ring (23) in order to insert ring (23) into accumulator (1). Unfold ring (23). Position ring (23) at the end of accumulator (1).
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   Illustration 5	g00524942

7. Pull plug (18) against accumulator (1) in order to seat plug (18), as shown.
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   Illustration 6	g00570098

8. Install washer (22), O-ring seal (21) and backup ring (20) onto accumulator (1).
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   Illustration 7	g00524940

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   Illustration 8	g00524941

9. Install spacer (19) onto plug (18). Use Tool (A) (not shown) in order to install locknut (17). Tighten locknut (17) to a torque of 102.5 ± 7.5 N·m (75.6 ± 5.52 lb ft).
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   Illustration 9	g00524930

10. Install valve (8) into adapter (7). Install O-ring (6) onto adapter (7).

11. The following procedure illustrates the preparation of the bladder prior to installation.

    1. Install valve assembly (4) onto the end of the bladder. Inflate the new bladder or the used bladder to normal size in order to check for leakage. Bladders should be inflated to a maximum of 21 kPa (3 psi).

    2. Use a solution of soap and water in order to check the bladder for leaks. If a leak is detected, the bladder must be replaced with a new bladder. After testing, deflate the bladder immediately.

    3. Remove valve assembly (4) from the end of the bladder. Purge the air from the bladder and fold the bladder lengthwise into a compact roll. Once the bladder is folded, install valve assembly (4).

12. Pour clean hydraulic oil into accumulator (1). Fill 10% of the volume of accumulator (1) with hydraulic oil.

    Note: The bladder is lubricated and cushioned by the hydraulic oil.

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    Illustration 10	g00527929

13. Insert bladder (3) into accumulator (1).
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    Illustration 11	g00524938

14. Insert plug (12) into accumulator (1).
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    Illustration 12	g00524937

15. Fold ring (16) in order to insert ring (16) into accumulator (1). Unfold ring (16). Position ring (16) at the end of accumulator (1).
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    Illustration 13	g00524936

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    Illustration 14	g00524935

16. Pull plug (12) against accumulator (1) in order to seat plug (12), as shown.

17. Install washer (15), O-ring seal (14) and backup ring (13) onto accumulator (1).
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    Illustration 15	g00524934

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    Illustration 16	g00524932

18. Install spacer (11) onto plug (12). Use Tool (A) in order to install locknut (10). Tighten locknut (10) to a torque of 102.5 ± 7.5 N·m (75.6 ± 5.52 lb ft).
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    Illustration 17	g00524931

19. Install nut (9) onto the end of bladder (3). Tighten nut (9) to a torque of 30.5 ± 3.5 N·m (22.5 ± 2.58 lb ft).
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    Illustration 18	g00524866

20. Install cover (2) onto accumulator (1).

End By:

1. Install the steering accumulator. Refer to Disassembly and Assembly, "Steering Accumulator - Install".