330,330 L & 330 LN EXCAVATORS MACHINE SYSTEMS Caterpillar

Main Hydraulic Pump & Pump Drive Coupling

Usage:

Remove & Install Main Hydraulic Pump & Pump Drive Coupling

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At operating temperature, the hydraulic oil tank is hot and under pressure. Hot oil can cause burns. To prevent possible personal injury, release the pressure in the implement hydraulic circuits (boom, stick and bucket) before any hydraulic lines or components are disconnected or removed.

1. Release the pressure in the hydraulic system as follows:

a. Fully retract the rod in the stick cylinder.

b. Adjust the position of the bucket so it will be flat on the ground when the boom is lowered.

c. Lower the boom until the bucket is flat on the ground.

d. Shut off the engine, and put the hydraulic activation control lever in the "Lock" position.

e. Move the control levers for the boom, bucket, stick and swing through their full travel strokes. This will relieve any pressure that may be present in the pilot system.

f. Slowly loosen the air breather cap on the hydraulic oil tank to release the pressure.

g. Tighten the air breather cap on the hydraulic oil tank.

h. The pressure in the hydraulic system has now been released. Lines and components can now be removed.

2. Remove the access cover from under the hydraulic oil tank. Drain the oil from the hydraulic oil tank into a suitable container. The capacity of the hydraulic oil tank is 310 liters (82 U.S. gal).

3. Remove the hood from the machine. The weight of the hood is 79 kg (175 lb).

4. Open the right rear access door.

5. Remove six bolts (2) and washers (3).

6. Remove cover assembly (4).

7. Remove four bolts (5) and washers (6).

8. Remove cover assembly (7).

9. Remove the support assemblies for cover assemblies (4) and (7).

10. Remove seven bolts (8) and the washers that hold upper plate (9) in position. Remove the upper plate.

11. Put identification marks on the seven hose assemblies that are connected to the main hydraulic pump for installation purposes.

12. Disconnect five hose assemblies (11) and (12).

13. Disconnect two hose assemblies (10) and (15).

14. Loosen two clamps (16).

15. Disconnect pipe assembly (13) from the main hydraulic pump.

16. Remove lower plate (14).

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NOTICE

The main hydraulic pump must be held level during removal and installation to prevent binding of the pump drive coupling in the engine flywheel.

17. Fasten a lifting strap and a hoist to main hydraulic pump (18) as shown. Remove twelve bolts (17) and the washers that hold the main hydraulic pump to the flywheel housing.

18. While keeping the main hydraulic pump level, remove it and the drive coupling from the engine flywheel and flywheel housing. The combined weight of the main hydraulic pump and the pump drive coupling is 250 kg (550 lb).

NOTE: If desired, four drive bolts (21) can be removed from spacer plate (20) with the spacer plate still fastened to the engine flywheel.

19. Remove eight bolts (19) and the washers that hold spacer plate (20) to the engine flywheel. Remove spacer plate (20). Remove four drive bolts (21) from spacer plate (20).

20. Remove four elements (22) from coupling assembly (23).

21. Loosen two setscrews (24), and remove coupling assembly (23) from the splined shaft of the main hydraulic pump.

22. Remove socket head bolt (25) and coupling (26) from the coupling assembly.

23. If necessary, remove two locating pins (27) from the coupling assembly.

24. Remove the other two couplings from the coupling assembly as in Steps 23 and 24.

NOTE: The following steps are for the installation of the main hydraulic pump and the pump drive coupling.

25. Assemble the coupling assembly. Install two locating pins (27) in the coupling assembly.

26. Put coupling (26) in position on the coupling assembly, and install socket head bolt (25) which holds it. Tighten the socket head bolt to a torque of 470 ± 20 N·m (350 ± 15 lb ft).

27. Install the other two couplings on the coupling assembly as in Steps 25 and 26.

28. Be sure the splined shaft of the main hydraulic pump is clean and free of dirt and debris. Put a thin coat of 5P0960 Multipurpose Grease on the splines of the shaft.

29. Install coupling assembly (23) on the splined shaft of the main hydraulic pump. Install the coupling until it is flush with the end of the splined shaft. If necessary, use a soft faced hammer to locate the coupling assembly on the splined shaft. Use a straight edge to be sure the end of the coupling assembly is even with the end of the splined shaft. Tighten two setscrews (24) to a torque of 210 to 10 N·m (155 to 7 lb ft).

30. Install four elements (22) in coupling assembly (23).

31. Put spacer plate (20) in its original position in the engine flywheel. Install eight bolts (19) that hold it.

32. Install four drive bolts (21) in the spacer plate, and tighten them.

33. Fasten a lifting strap and a hoist to main hydraulic pump (18). While holding the main hydraulic pump level, put it in position on the engine flywheel housing. Be sure the holes in the elements on the drive coupling are in alignment with the four drive bolts in the spacer plate in the engine flywheel. Push the hydraulic pump into position against the engine flywheel housing.

34. Install the washers and twelve bolts (17) that hold the main hydraulic pump in position.

35. Reinstall lower plate (14).

36. Check the condition of all O-ring seals used in the ends of the hose assemblies and pipe assembly which connect to the main hydraulic pump. If any of the seals are worn or damaged, use new parts for replacement.

37. Connect pipe assembly (13) to the main hydraulic pump.

38. Re-tighten two clamps (16).

39. Connect hose assemblies (10) and (15) to the main hydraulic pump.

40. Connect five hose assemblies (11) and (12) to the main hydraulic pump.