318C and 319C Excavators Caterpillar

4000 Hour Oil Change Interval

A 4000 hour maintenance interval for hydraulic oil (change) is available. The extended interval requires S·O·S monitoring of the hydraulic oil. The interval for S·O·S monitoring is every 500 hours. The maintenance interval for the hydraulic oil filter is not changed. If S·O·S monitoring is not performed, the 2000 hour maintenance interval must be used.

Machines with hammers are not included in the 4000 hour maintenance interval. Machines with hammers must use the intervals that are listed in the Maintenance Interval Schedule. Machines that are used in severe conditions are not included in the 4000 hour maintenance interval. Machines that are used in severe conditions must use the interval in the Maintenance Interval Schedule.

Lubricants

Approved hydraulic oil must be used to obtain the 4000 hour hydraulic oil change. Refer to the list that follows for approved oils.

Caterpillar Hydraulic Oils

• Cat HYDO

• TDTO

• TDTO (TMS)

• DEO

• Biodegradable Hydraulic Oil (HEES)

• MTO

Commercial Oils

Diesel engine oils (Heavy Duty) with a minimum zinc content of 900 ppm can be used. Acceptable commercial oils are identified by the American Petroleum Institute trademark (API). Refer to the list that follows for acceptable types of hydraulic oils.

• CF

• CF-4

• CG-4

• CH-4

Note: Industrial hydraulic oils are not recommended for the hydraulic systems of Caterpillar machines. Industrial hydraulic oils are more likely to allow corrosion and Industrial hydraulic oils are more likely to allow excessive wear.

Procedure to Change the Hydraulic Oil

Illustration 1	g00101435

1. Park the machine on level ground. Lower the bucket to the ground so that the stick is vertical.

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Illustration 2	g00687272

2. Remove bolts (1), washers (2) and cover (3) from the top of the hydraulic tank.

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Illustration 3	g00687312

3. Clean the area thoroughly in order to keep dirt out of the screen cover. Clean the area thoroughly in order to keep dirt out of the fill/vent plug.

4. Relieve the internal pressure from the hydraulic tank by loosening the fill/vent plug. After the pressure is relieved, remove the fill/vent plug.

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Illustration 4	g00101446
The oil drain valve is located under the hydraulic tank.

5. Remove the hydraulic tank access cover that is located under the upper structure. This will allow access to the drain valve.

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Illustration 5	g00687273
(4) Plug

Note: Refer to Operation and Maintenance Manual, "General Hazard Information" for information that pertains to containing fluid spillage.

6. Remove plug (4) .

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Illustration 6	g00687274
(5) Pipe Nipple (6) Hose (7) Drain plug

7. Install a 3B-7271 Pipe Nipple (5) with hose (6) into the hole on the bottom of the hydraulic tank.

8. Loosen drain plug (7) in order to drain the oil.

9. Drain the oil into a suitable container.

10. After the oil has been drained, tighten drain plug (7) to a torque of 110 ± 15 N·m (81 ± 11 lb ft).

11. Remove Pipe Nipple (5) and hose (6) .

12. Clean plug (4) and install the plug. Tighten the plug to a torque of 75 ± 5 N·m (55 ± 48 lb ft).

13. Open the access door on the right side of the machine.

14. Clean the pump, the hydraulic lines, and the hydraulic tank.

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Illustration 7	g00687275

15. Remove the plug from the tube. Allow the oil to drain into a container.

    Note: Dispose of used filters and used fluids according to local regulations.

16. Inspect the O-ring. Replace the O-ring if wear or damage is evident.

17. Clean the plug. Install the plug and the O-ring into the drain port.

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Illustration 8	g00687277
(8) Bolts (9) Washers (10) Cover (11) Spring (12) Screen

18. Remove bolts (8), washers (9) and cover (10) .

    Note: Dispose of used filters and used fluids according to local regulations.

Note: Do not allow spring (11) to fall back into the tank.

19. Remove spring (11) and screen (12) .

    Note: Refer to Operation and Maintenance, "General Hazard Information" for information on containing fluid spillage.

20. Wash the screen in a clean nonflammable solvent. Allow the screen to dry. Inspect the screen. Replace the screen, if the screen is damaged.

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Illustration 9	g00687278
(13) O-ring seal (14) O-ring seal

21. Remove O-ring seal (13) from the screen.

22. Inspect O-ring seals (13) and (14). Replace the O-ring seals if wear or damage is evident.

23. Install O-ring seal (13) on screen (12) .

24. Install screen (12) and spring (11). Then install cover (10), washers (9), and bolts (8) .

    Note: Make sure that the O-ring seals and the spring are properly positioned during installation.

25. Fill the hydraulic system oil tank. Refer to Operation and Maintenance Manual, "Capacities (Refill)".

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Illustration 10	g00687312

26. Inspect the O-ring seal on the filler plug for damage. Replace the O-ring, if necessary. Clean the filler plug. Install the filler plug.

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Illustration 11	g00687281

27. Remove the pressure cap.

28. Inspect the pressure cap. Clean the pressure cap. Replace the pressure cap if damage is evident.

29. Replace the pressure cap.

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Illustration 12	g00753020
(15) Drain hose (16) Connector (17) Seal (18) Negative flow control hose

Note: Make no attempt to start the engine until the pump has been filled with hydraulic oil. Serious damage to the hydraulic components can result.

30. When the hydraulic oil has been replaced, the air must be removed from the hydraulic oil system. To remove the air from the hydraulic oil system, follow Step 30.a through Step 30.g.

    1. While the engine is stopped, remove drain hose (15), connector (16) and seal (17) from the top of the pump. Add hydraulic oil through the opening.

    2. Check the condition of seal (17). If the seal is damaged, replace the seal.

    3. After the pump has been filled with oil, install drain hose (15), connector (16) and seal (17) to the original locations.

    4. Start the engine. When the engine is at low idle, fully raise the boom. Hold the boom in this position.

    5. Slowly loosen negative flow control hose (18) until the air has been released from the pump.

    6. Tighten negative flow control hose (18) .

    7. Stop the engine. Slowly lower the boom until the bucket is on the ground. This pressurizes the hydraulic tank.
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    Illustration 13	g00687285
    (19) Vent plug

    8. Slowly loosen vent plug (19) until the hydraulic oil flows out of the opening. This indicates that the air has been released from the pump.

    9. Tighten vent plug (19) .

31. Start the engine. Operate the engine at idling speed for five minutes.

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Illustration 14	g00101435

32. Operate the joysticks in order to circulate the hydraulic oil. Lower the bucket to the ground so that the stick is vertical to the ground. Stop the engine.

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Illustration 15	g00687286

33. Maintain the oil level between the marks on the sight gauge in the appropriate temperature range.

34. Close the access door.