M313D, M315D, M316D, M318D and M322D Wheeled Excavators and M318D MH and M322D MH Wheeled Material Handlers Hydraulic System Caterpillar

Show/hide table

Personal injury or death can result from sudden machine movement. Sudden movement of the machine can cause injury to persons on or near the machine. To prevent injury or death, make sure that the area around the machine is clear of personnel and obstructions before operating the machine.

Introduction

The test measure the charge pressure of the ride control accumulators, and checks for the correct opening and closing of the ride control solenoids.

Machine Preparation

1. Clear all personnel from the machine and from the area around the machine.

2. Start the engine.

Show/hide table



Illustration 1	g02449876
Engine speed dial

3. Set the engine speed dial at "10".

4. Lower the left console.

5. Position the machine on level ground. Check the visibility and adjust the mirrors for the best vision close to the machine.

6. Fully depress the service brake pedal until the service brake pedal locks mechanically.

7. Increase the hydraulic oil temperature to 46 to 80° C (115 to 176° F).

8. Lower the stabilizers and the blade tip.

Show/hide table



Illustration 2	g02552721
Power mode control button located on the soft panel switch

9. Push down on the power mode control button in order to activate power mode.

   Note: The indicator light will be illuminated when power mode is activated.

10. Use the Monitor in the cab in order to disable the Automatic Engine Speed Control.

    1. Select the "Performance" menu from the main menu on the monitor.

    2. Select "AESC Status" from the "Performance" menu and change the value to "Inactive".

    3. Press the "OK" key.

Show/hide table



Illustration 3	g02447064
Joystick (front switch)

11. Disable the hydraulic modulation control, if equipped. Press the front switch on the right joystick in order to deactivate hydraulic modulation.

12. The air conditioning should be turned off for the following procedures.

Check the Charge Pressure for the Accumulators

1. Read all pressures on the monitor. Access the display by selecting the following menus in sequence: "SERVICE", "STATUS", and "ANALOG IN STATUS"

Show/hide table



Illustration 4	g02553157
Ride control button located on the soft panel switch

2. Disable the ride control function at the soft switch panel by pushing down on the button for ride control.

   Note: The indicator light will not be illuminated when the ride control function has been disabled.

3. Lower the implement to the ground until the head end pressure for the boom cylinder is less than 3000 kPa (435 psi).

4. Stop the engine.

5. Turn the ignition key to the ON position.

Show/hide table



Illustration 5	g02365136
(1) Ride control accumulator #1 (2) Ride control accumulator #2 (3) Ride control solenoid (4) Head end pressure (Boom cylinder) (5) Ride control solenoid (6) Ride control solenoid

6. Read "Ride Control Accu #1" and "Ride Control Accu #2" pressures on the monitor. Refer to Table 1 for the correct charging pressure and temperature relationship for the accumulators. The pressure reading for both ride control accumulators should be equal to 500 kPa (73 psi).

7. If the charge pressure for the ride control accumulators is not correct, charge the accumulators to the correct gas pressure.

Check if Solenoids Close Correctly

Note: The following procedure checks the correct closing of ride control solenoids (3) , (5) , and (9) .

Show/hide table



Illustration 6	g02452604
Engine speed dial

1. Set the engine speed dial at "1".

2. Deactivate the ride control function at the soft switch panel by pushing down on the button for ride control.

   Note: The indicator light will not be illuminated when the ride control function has been disabled.

3. Release the pressure of the ride control accumulators by moving the implements to the ground until the "Boom Cylinder Head Pressure" is less than a pressure of 3000 kPa (435 psi).

4. Stall the BOOM UP control.

5. Verify that the "Boom Cylinder Head Pressure" is greater than a pressure of 30000 kPa (4351 psi). The pressure reading for "Ride Control Accu #1" and "Ride Control Accu #2" should be around the value that was measured at Step 6 of the "Check the Gas Charge Pressure for the Accumulators" procedure.

6. Stall the BOOM DOWN control.

Show/hide table



Illustration 7	g02365397
Typical example of a main control valve for the M316D (7) Rod end pressure (Boom cylinder)

Show/hide table



Illustration 8	g02365320
Typical example of a main control valve for the M318D and M322D (7) Rod end pressure (Boom cylinder)

7. Use the machine implement to lift the machine slightly off the ground.

8. Verify that "Boom Cylinder Rod Pressure" is equal to or greater than 13000 kPa (1885 psi).

   Note: This pressure should remain constant and stable for several seconds.

Check if Solenoids Open Correctly

Note: The following procedure checks the correct opening of ride control solenoids (3) , (5) , and (6) .

1. Set the engine speed dial at "1".

Show/hide table

Ride control activation/operation may cause sudden movement of the boom. Boom movement may cause personal injury or death. Be sure no one is under or near the boom before activating ride control. Keep all personnel away from the boom area during ride control operation.

2. Activate the ride control function at the soft switch panel by pushing down on the button for ride control.

   Note: The indicator light will be illuminated when the ride control function is activated.

   Note: Refer to Operation and Maintenance Manual, SEBU8694, "Operator Controls" for additional information concerning activation of the ride control function.

3. Stall the BOOM UP control.

4. Verify the "Boom Cylinder Head Pressure", and the pressure for "Ride Control Accu #1" and "Ride Control Accu #2".

   Note: All three pressures should be nearly the same pressure.

5. Stall the BOOM DOWN control.

6. Verify the "Boom Cylinder Rod Pressure" is less than 6000 kPa (870 psi).

   Note: This pressure should remain constant and stable for several seconds.

7. Testing the ride control is now completed.

Worksheet