793C Off-Highway Truck Machine Systems Caterpillar

Assembly Procedure

Note: Before assembly, be certain that all the parts of the steering pump are clean. Check all the O-ring seals for damage. If necessary, replace any damaged O-ring seals.

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Illustration 1	g00380127

1. Install O-ring seal (77) on plug (76). Install plug (76).

2. If necessary, install spring pins (75) in steering pump housing (3). Tighten plug (76) to a torque of 79 ± 4 N·m (58 ± 3 lb ft).
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   Illustration 2	g00382497

3. Use Tool (A) to install retaining ring (74) in steering pump housing (3).
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   Illustration 3	g00382498

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   Illustration 4	g00382517

4. Use Tool (B) and a hammer to install seal (73) in steering pump housing (3).
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   Illustration 5	g00380122

5. Use two screws (69) to install swashplate bearings (70) and (72) in steering pump housing (3). Tighten screws (69) to a torque of 4 ± .4 N·m (2.95 ± 0.29 lb ft).

6. Install bearing cup (71) in steering pump housing (3). Be certain that bearing cup (71) is properly seated in steering pump housing (3).
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   Illustration 6	g00380120

7. Install bearing cone (68) in steering pump housing (3).
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   Illustration 7	g00383192

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   Illustration 8	g00383279

8. Check stops (78) in swashplate (62) for wear or for damage. If the stops are worn or damaged, replace the stops.
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   Illustration 9	g00383292

9. Install swashplate (62) in steering pump housing (3).
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   Illustration 10	g00383313

10. Position steering pump housing (3), as shown. Install pump shaft (49).
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    Illustration 11	g00383315

11. Install bearing cone (48) on pump shaft (49). Install gasket (34) on steering pump housing (3). Do not install shim pack (50) (not shown) at this time.
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    Illustration 12	g00383352

12. Install socket head bolts (32) and (33) in pump head (31). Tighten socket head bolts (33) to a torque of 115 ± 12 N·m (84.8 ± 8.9 lb ft). Tighten socket head bolts (32) to a torque of 286 ± 29 N·m (210.9 ± 21.4 lb ft).
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    Illustration 13	g00383412

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    Illustration 14	g00383452

13. Attach Tool (C) and a suitable lifting device to pump head (31). Position steering pump housing (3), as shown.

14. Position Tool (D), as shown. Set the bezel to zero.

15. Position the open end wrench on the block of wood that is beneath the shaft splines, as shown. Lift up on the shaft.

16. Record the reading on the dial indicator in order to determine the amount of shaft end play. Insert the proper amount of shims that will provide an end play of .0508 ± .0254 mm (0.002 ± 0.001 inch).

17. Remove Tool (D) from steering pump housing (3).

18. Remove the components that were installed in Steps 11 through 12.
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    Illustration 15	g00379815

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    Illustration 16	g00379855

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    Do not remove the retaining ring until the spring force has been released. Failure to do so could result in personal injury or death. In order to prevent this, use a suitable press to hold the spring force while the retaining ring is removed. Slowly release the spring tension with the press after the retaining ring has been removed.

19. Install guide (53), spring (54), guide (55), and retaining ring (52) in barrel (51).

    Note: Guides (53) and (55) are different sizes. The guides should be identified for the purposes of the assembly. The guide with the smaller diameter goes into the barrel first. The guide with the larger diameter fits below the retaining ring.

20. Position barrel (51) on a suitable press, as shown. Use Tool (A) to install retaining ring (52) in barrel (51).
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    Illustration 17	g00383454

21. Inspect retaining plate (67) for wear or for damage. If necessary, replace retaining plate (67).
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    Illustration 18	g00383455

22. Inspect nine pistons (66) for wear or for damage. If necessary, replace a piston. Dimension X must be maintained on all nine piston shoes within .0254 mm (.001 inch). The shoe must swivel smoothly on the ball. The end play must not exceed .1270 mm (.005 inch).
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    Illustration 19	g00380119

23. Install nine pistons (66) in retaining plate (67).
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    Illustration 20	g00383674

24. Install pistons (66) and retaining plate (67) in barrel (51).
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    Illustration 21	g00383675

25. Install barrel assembly (51) in steering pump housing (3).
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    Illustration 22	g00383677

26. Apply 4C-4030 Thread Lock Compound to the threads of socket head bolts (63). Install two limiter spacers (65), two limiter plates (64), and four socket head bolts (63) to swashplate (62). Tighten socket head bolts (63) to a torque of 34 ± 3 N·m (25.1 ± 2.2 lb ft).

    Note: The bronze side of limiter plates (64) should face limiter spacers (65).

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    Illustration 23	g00380095

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    Illustration 24	g00383679

27. Install O-ring seal (60) on plug (59).

28. Install plug (59) in steering pump housing (3). Tighten plug (59) to a torque of 101.5 ± 4.5 N·m (74.86 ± 3.3 lb ft).
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    Illustration 25	g00383752

29. Position O-ring seal (58) (not shown) on cover (57).

30. Position cover (57) on steering pump housing (3). Install three bolts (56). Tighten bolts (56) to a torque of 8.5 ± 1 N·m (6.27 ± 0.74 lb ft).
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    Illustration 26	g00383815

31. Install shim pack (50) and bearing (48) on pump shaft (49).
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    Illustration 27	g00383816

32. If rod (39) was removed, install O-ring seal (46) on rod (39). If rod (38) was removed, install O-ring seal (45) on rod (38). Apply 4C-4030 Thread Lock Compound to the threads of rod (38) and rod (39). Install rod (38) and rod (39) in pump head (18). Tighten rod (38) and rod (39) to a torque of 79 ± 4 N·m (58.3 ± 2.9 lb ft).

    Note: Refer to the note in Disassembly and Assembly, "Piston Pump (Steering) - Disassemble" for information on poppet (42) and seat (43).

33. Install bearing cup (47) in pump head (31).
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    Illustration 28	g00383819

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    Illustration 29	g00383892

34. Install pin (41) in pump head (31).

35. Install valve plate (40) on pump head (31). Be certain that the notch in valve plate (40) is aligned with pin (41).
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    Illustration 30	g00384073

36. Install piston (35) on rod (38). Install bias spring (36) and bias piston (37) on rod (39).
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    Illustration 31	g00384074

37. Install Tool (E) in steering pump housing (3). Install new gasket (34) on steering pump housing (3).
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    Illustration 32	g00384092

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    Illustration 33	g00378855

38. Use Tool (E) as a guide. Install pump head (31) on steering pump housing (3).

39. Install four socket head bolts (33) in steering pump housing (3). Hand tighten the four socket head bolts. Remove Tool (E) from steering pump housing (3).
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    Illustration 34	g00378648

40. Install two socket head bolts (32) in steering pump housing (3). Hand tighten the two socket head bolts. Tighten four socket head bolts (33) to a torque of 115 ± 12 N·m (84.8 ± 8.9 lb ft). Tighten two socket head bolts (32) to a torque of 286 ± 29 N·m (210.9 ± 21.4 lb ft).

End By:

1. Install the pressure and flow compensator valve in the piston pump. Refer to Disassembly and Assembly, "Pressure and Flow Compensator Valve - Assemble" for the correct procedure.

2. Install the piston pump in the machine. Refer to Disassembly and Assembly, "Piston Pump (Steering) - Install" for the correct procedure.