330,330 L & 330 LN EXCAVATORS MACHINE SYSTEMS Caterpillar

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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 six bolts (1), the washers and spacers that hold cover plate (2) in position under the hydraulic oil tank. Remove the cover plate.

View From Under Hydraulic Oil Tank

3. Remove drain plug (5) to drain the oil from 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).

4. Remove four bolts (3) and the washers to disconnect pipe assembly (4) from the bottom of the hydraulic oil tank.

View From Under Hydraulic Oil Tank

5. Remove four bolts (6) and the washers that hold the hydraulic oil tank to the frame of the machine.

6. Open the right rear access door.

7. Disconnect pipe assembly (7) from the side of the hydraulic oil tank.

8. Disconnect hose assembly (8) from the side of the hydraulic oil tank.

9. Disconnect clip (9) from the side of the hydraulic oil tank.

10. Disconnect electrical connector (10).

11. Remove cover assembly (11) from the top of the hydraulic oil tank.

12. Fasten tool (A) and a hoist to the top of hydraulic oil tank (12) as shown. Carefully remove the hydraulic oil from the machine. The empty weight of the hydraulic oil tank is approximately 193 kg (425 lb).

13. Put identification marks on the shims used between the frame of the machine and the hydraulic oil tank for installation purposes. Remove the shims from the frame of the machine.

NOTE: The following steps are for the installation of the hydraulic oil tank.

14. Check the condition of all O-ring seals used in the hose assemblies and pipe assemblies that are connected to the hydraulic oil tank. If any of the seals are worn or damaged, use new parts for replacement.

15. Put the shims for the hydraulic oil tank in their original position on the frame of the machine.

16. Fasten tool (A) and a hoist to hydraulic oil tank (12). Put the hydraulic oil tank in position on the frame of the machine. Install four bolts (6) and the washers that hold it in place.

17. Connect electrical connector (10).

18. Reinstall clip (9) on the side of the hydraulic oil tank.

19. Connect pipe assembly (7) to the side of the hydraulic oil tank.

20. Connect hose assembly (8) to the side of the hydraulic oil tank.

21. Connect pipe assembly (4) to the bottom side of the hydraulic oil tank.

22. Be sure drain plug (5) is tight.

23. Reinstall cover plate (2) under the hydraulic oil tank.

24. Reinstall cover assembly (11) on top of the hydraulic oil tank.

25. Fill the hydraulic oil tank with oil to the correct level. See the Operation & Maintenance Manual for the correct filling procedure.