Usage:
Start By:
a. remove hood assembly*
*This operation is in the appropriate Engine Supplement For 320B, 320B L and 320B N Hydraulic Excavators Disassembly & Assembly module.
Fluid Spillage Containment
Care must be taken to ensure that the fluids are contained during performance of the inspection, the maintenance, the testing, the adjusting and the repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to the "Tools And Shop Products Guide, NENG2500" the tools and the supplies suitable to collect and contain any of the fluids in Caterpillar machines. Dispose of the fluids according to local regulations and mandates.
1. Start the machine, and fully extend the stick and the bucket. Lower the stick and the bucket to the ground.
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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 all of the implement hydraulic circuits (the boom, the stick and the bucket) before any of the hydraulic lines or any of the components are disconnected or removed. |
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2. Release the pressure in all of the implement hydraulic circuits (the boom, the stick and the bucket) before any of the hydraulic lines or any of the components are disconnected or removed. Release the pressure as follows:
a. Shut off the engine and place key in the "ON" position. Put the hydraulic activation control lever in the "UNLOCK" position.
b. Move the control levers for the boom, the stick and the swing to all full stroke positions. This will release any pressure that might be present in the pilot system.
c. Return the key to "OFF" position.
d. Slowly loosen the fill plug on the hydraulic tank and release the pressure.
e. Tighten the fill plug on the hydraulic tank. Tighten the fill plug to a torque of 68 ± 7 N*m (50 ± 5 lb ft).
f. The pressure in the hydraulic system has been released and the hydraulic lines and the components can be removed.
3. Remove 12 bolts (1), the washers and cover assembly (2).
4. Remove six bolts (3), the washers and upper plate (4).
5. Remove four nuts (7) and two U-bolts (6) that hold muffler assembly (5) to the mounting bracket. Loosen two nuts (9). Remove muffler assembly (5).
6. Remove six bolts (10) that hold muffler assembly mounting bracket (11) to the engine.
7. Put identification marks on all of the hose assemblies and the tube assemblies that are connected to the main hydraulic pump for installation purposes.
8. Oil will drain from the hose assemblies and the tube assemblies that are connected to the main hydraulic pump. Place a suitable drain pan under the main hydraulic pump to collect the drain oil.
9. Disconnect eight hose assemblies (13) from the main hydraulic pump. Put plugs in the ends of the hose assemblies to prevent loss of oil and to keep contaminants out of the hydraulic system.
10. Remove three bolts (12) and the washers that hold remote engine oil filter and base (14) in position. Lower the engine oil filter and the base down on the lower cover assemblies for the machine.
11. Remove two bolts (15) and the washers that hold mounting bracket assembly (11) for the muffler assembly to the main pump housing. Remove the mounting bracket assembly.
12. Loosen four clamps (16). Remove hose assembly (17) from tube assembly (19).
13. Remove four bolts (18) and the washers, and disconnect tube assembly (19) from the main hydraulic pump.
14. Remove three bolts (20) and the washers that hold wiring harness (21) in position. Disconnect wiring harness (21).
15. Remove five bolts (23) and the washers that hold lower plate (22) in position. Tilt the lower plate to gain access to main hydraulic pump mounting bolts (15).
| NOTICE |
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The main hydraulic pump must be held level during the removal and the installation to prevent binding of the pump drive coupling in the engine flywheel. |
16. Fasten a lifting sling and a hoist to main hydraulic pump (24) as shown.
17. Remove ten remaining bolts (15) 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 the flywheel housing. The combined weight of the main hydraulic pump and the pump drive coupling is 145 kg (320 lb).
19. Remove four socket head bolts (25), coupling (27) and spacer (26) from the engine flywheel.
20. Remove element (28) from inserts (29).
21. Remove four inserts (29) from spacer (26).
22. Loosen two setscrews (30). Remove coupling assembly (31) from main hydraulic pump (24).
23. Remove four socket head bolts (34) and four inserts (33) from hub (32).
24. Remove locating pins (35) from hub (32).
NOTE: The following steps are for the installation of the main hydraulic pump and pump drive coupling.
25. Check the condition of all O-ring seals used in the ends of the tube assemblies and the hose assemblies that connect to the main hydraulic pump. If any of the O-ring seals are damaged, use new parts for replacement.
26. Install locating pins (35) in hub (32).
27. Install four inserts (33) and four socket head bolts (34) in hub (32). Tighten the four socket head bolts to a torque of 310 ± 10 N*m (230 ± 7 lb ft).
28. Make sure the splined shaft of the main hydraulic pump is clean. Apply 5P-0960 Multipurpose Grease on the splined shaft.
29. Install coupling assembly (31) on the splined shaft of main hydraulic pump (24). Install the coupling assembly until it is even 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 make sure the coupling assembly is even with the end of the splined shaft. Tighten two setscrews (30) to a torque of 110 ± 10 N*m (80 ± 7 lb ft).
30. Install four inserts (29) on spacer (26).
31. Install element (28) on inserts (29).
32. Position coupling (27) on the engine flywheel. Install four socket head bolts (25). Tighten socket head bolts (25) to a torque of 215 ± 10 N*m (159 ± 7 lb ft).
33. Fasten a lifting sling and a hoist to main hydraulic pump (24) as shown. Carefully install the main hydraulic pump on the engine flywheel housing. Make sure the coupling assemblies are in alignment with each other. Push the main hydraulic pump against the flywheel housing.
34. Install ten bolts (15) and the washers that hold the main hydraulic pump to the engine flywheel housing.
35. Put lower plate (22) in position. Install five bolts (23) and the washers that hold it.
36. Connect wiring harness (21). Install three bolts (20) and the washers that hold wiring harness (21) in position.
37. Connect tube assembly (19) to the main hydraulic pump with four bolts (18) and the washers.
38. Connect hose assembly (17) to tube assembly (19). Install four clamps (16).
39. Position muffler assembly mounting bracket assembly (11) on the back of the engine. Install two bolts (15) and the washers that hold it.
40. Put remote engine oil filter and base (14) in position. Install three bolts (12) that hold it.
41. Connect eight hose assemblies (13) to the main hydraulic pump in their original locations. Refer to the appropriate "320B, 320B L and 320B N Hydraulic Excavators, Hydraulic System Specifications Manual", for specific torque values for all hose assemblies in the various lines groups.
42. Install six bolts (10) that hold muffler assembly mounting bracket (11) to the back side of the engine.
43. Put muffler assembly (5) in position on muffler assembly mounting bracket (8). Install two U-bolts (6) and four nuts (7) that hold the muffler assembly in position. Tighten two nuts (9).
44. Install upper plate (4) and six bolts (3) and the washers that hold the plate in position.
45. Install cover assembly (2) and 12 bolts (1) and the washers that hold the cover assembly in position.
NOTE: Refer to the topic "Lubricant Viscosities and Refill Capacities" in the "Operation & Maintenance Manual" for the proper filling procedure and the proper levels for the hydraulic system.
46. Fill the hydraulic oil tank with oil to the correct level.
| NOTICE |
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When the main hydraulic pump has been serviced or the hydraulic oil has been replaced, the air in the hydraulic system must be removed. No attempt should be made to start the engine until the main hydraulic pump has been filled with oil, or serious damage can be caused to the hydraulic components. |
47. With the engine stopped, remove air vent plug (36) located on top of the main hydraulic pump. Leave the plug off for several minutes until the main pumps are filled with hydraulic oil. After the pumps are filled with hydraulic oil, tighten the air vent plug, and start the engine. With the engine at low idle, fully raise the boom, and hold it in this position.
48. Stop the engine, and slowly lower the boom until the bucket is on the ground. This will pressurize the hydraulic oil tank.
49. Slowly loosen the air vent plug several turns until hydraulic oil flows out of the opening. This is an indication that the air has been completely released from the main hydraulic pump.
50. Tighten air vent plug (36).
End By:
a. install hood assembly*
*This operation is in the appropriate Engine Supplement For 320B, 320B L and 320B N Hydraulic Excavators Disassembly & Assembly module.