M318 Excavator Hydraulic System Caterpillar

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Illustration 1	g00293505
The pressure taps are located in the battery compartment. (1) Main pump pressure (2) Proportional reducing valve pressure (Main pump)

1. Connect a 60000 kPa (8600 psi) pressure gauge to pressure tap (1) .

2. Connect a 4000 kPa (580 psi) pressure gauge to pressure tap (2) .

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Illustration 2	g00817270
Left side of cab seat (3) Service connector

3. Connect a laptop computer or 123-6471 Diagnostic Tool Group to the service connector (3) .

   Note: Refer to Special Instruction, SEHS9825 for the use of the 123-6471 Diagnostic Tool Group .

   Note: Refer to Special Instruction, REHS0701, "Instructions for the Use of the M300 Technician Software with a Laptop Computer".

4. Start the engine.

5. Place the AEC switch in the OFF position and move the heavy lift switch to the OFF position.

M300 Technician

1. Place the engine speed dial at the HIGH IDLE position.

2. Lower the left console.

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Illustration 3	g00852888
Main control valve (4) Locknut (5) Adjustment screw (main relief valve pressure)

3. Loosen locknut (4) .

4. Turn adjustment screw (5) by three full turns counterclockwise.

5. Stall the bucket.

6. Turn adjustment screw (5) clockwise and watch the pressure gauge on pressure tap (1). Continue turning the adjustment screw clockwise until the pressure is 10000 kPa (1450 psi).

7. Start M300 Technician.

8. Select "Configuration".

9. Use the arrow keys to select the "Operation Mode" option.

10. Select "Change Value".

11. Select the "Constant" option.

12. Select "OK".

13. Use the arrow keys to select the "Current Adjust" option.

14. Select "Change Value".

15. Use the arrow keys to change the numeric value until the pressure gauge reading at pressure tap (2) is approximately 3000 kPa (435 psi). Start with a numeric value of 180.

16. Select "Close".

17. Select "Status".

18. Verify that "Engine Speed" is shown. If "Engine Speed" is not shown, add "Engine Speed" to the parameters list.

19. Select "Engine Speed".

20. Turn the engine speed dial to the HIGH IDLE position and activate Mode II.

21. Move the joystick to the full BUCKET CLOSE position.

22. Turn the adjustment screw on the main relief valve clockwise until the engine speed is approximately 1950 rpm.

    Note: The pressure reading at pressure tap (1) should be a minimum of 20000 to 20500 kPa (2900 to 2972 psi).

    Note: If the pressure is not reached, check the engine.

23. After the engine speed has been checked, return the main relief valve to the original setting.

    Note: Refer to Testing and Adjusting, "Relief Valve (Main) - Test and Adjust".

24. In order to return the machine to the "Normal" operation mode, turn the engine start switch to the OFF position and back to the ON position without starting the engine.

Note: Do not use the "Teach" option.

PDT

1. Place the engine speed dial at the HIGH IDLE position.

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Illustration 4	g00852888
Main control valve (4) Locknut (5) Adjustment screw (main relief valve pressure)

2. Loosen locknut (4) .

3. Turn adjustment screw (5) by three full turns counterclockwise.

4. Stall the bucket.

5. Turn adjustment screw (5) clockwise and watch the pressure gauge on pressure tap (1). Continue turning the adjustment screw clockwise until the pressure is 10000 kPa (1450 psi).

6. Select the "F1 Config/Cal" function.

7. Select the "8 Operation Mode" function.

8. Use the arrow keys to select the "Const. Operation" function.

9. Press the "ENTER" key.

10. Select the "2 Current Adjust" function.

11. Use the arrow keys to change the numeric value until the pressure gauge reading at pressure tap (2) is approximately 3000 kPa (435 psi). Start with a numeric value of 180.

12. Select the "PROC STATUS" function.

13. Select the "5 Engine RPM" function.

14. Turn the engine speed dial to the HIGH IDLE position and activate Mode II.

15. Move the joystick to the full BUCKET CLOSE position.

16. Turn the adjustment screw on the main relief valve clockwise until the engine speed is approximately 1950 rpm.

    Note: The pressure reading at pressure tap (1) should be a minimum of approximately 20000 to 20500 kPa (2900 to 2972 psi).

    Note: If the pressure is not reached, check the engine.

17. After the engine speed has been checked, return the main relief valve to the original setting.

    Note: Refer to Testing and Adjusting, "Relief Valve (Main) - Test and Adjust".

18. In order to return the machine to the "Normal" operation mode, turn the engine start switch to the OFF position and back to the ON position without starting the engine.

Note: Do not use the "Teach" option.