MH3022, MH3024 and MH3026 Material Handlers Hydraulic System Caterpillar

Specification

Illustration 1	g06178733

Illustration 2	g06178741

Introduction

This procedure is utilized to test the maximum engine and main pump power by raising the main pump power until the 100 percent of the rated load speed of the engine has been met.

Note: This test should only be performed if the machine does not pass the "Main Pump Calibration" procedure. If the machine passes the "Main Pump Calibration" procedure, then the engine torque and main pump power are within specifications.

Required Tools

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Machine Preparation

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

2. Start the engine.
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   Illustration 4	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 60° C (115° to 140° F).

8. Fully extend the bucket cylinder and place the bucket on the ground.

9. Stop the engine.

10. Release the pressure in the hydraulic system.

    Note: Refer to Testing and Adjusting, "System Pressure - Release".

11. Raise the left console.
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    Illustration 5	g03793038
    The pressure tap is located behind the left front access door. (1) Main pump pressure tap (2) Main pump powershift pressure tap

12. Attach Tooling (B2) 60,000 kPa (8,702 psi) pressure sensor to main pump pressure tap (1) and (B2) 6,000 kPa (870 psi) pressure sensor to main pump powershift pressure tap (2).
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    Illustration 6	g03722485
    Service connector on the right side of cab behind the seat

13. Connect tooling (E) to the service connector.

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

15. Start the engine.

16. Use the monitor in the cab to set the desired fan speed.
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    1. Press the "Menu" key to display the main menu options.
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    2. Use the arrows to select the "Service" mode from the "Main Menu". Press the "OK" key.

    3. Input the password "FFF2". Press the "Enter" key.
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    4. Select the "Override" mode from the "Service" menu. Press the "OK" key.
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       Illustration 10	g06034824

    5. Select "Desired Fan Speed" from the "Override" menu.

    6. Set the fan speed at 1200 rpm.

17. The air conditioning should be turned off for the following test.

18. Lower the left console.

19. Lower the stabilizers, the blade tip, and/or the implement to raise the front axle and the rear axle. This step will allow the wheels to turn freely.

    Note: All tires must be fully off the ground.

20. Fully extend the bucket cylinder and place the bucket on the ground.
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    Illustration 11	g02446738
    Power mode control button on the soft panel switch

21. Push down on the power mode control button to activate power mode.

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

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    Illustration 12	g02453444
    Transmission control button on the soft panel switch

22. Push down on the transmission control button to select Second GEAR.

    Note: The second indicator light will illuminate when the transmission is in Second GEAR.

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    Illustration 13	g02453447
    Creeper speed control button on the soft panel switch

23. Push down on the creeper speed control button to activate the creeper speed control.

    Note: The indicator light will be illuminated when the creeper speed control is activated.

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    Illustration 14	g02447036
    Automatic Engine Speed Control (AESC) as displayed on the programmable function key in the monitor.

24. Disable the automatic engine speed control through the monitor by pressing the programmable button.
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    Illustration 15	g03722432
    Hydraulic modulation switch on left joystick

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    Illustration 16	g06174873
    Hydraulic modulation medium mode (monitor display)

25. Select the hydraulic modulation mode as medium. Press the lower front switch on the left joystick to select the hydraulic modulation mode.

Test Procedure

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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.

1. Release the service brake pedal.

2. Fully depress the travel pedal and stall the bucket in the full Bucket Open position.

3. Override the "Main Pump Power Shift Pressure Solenoid Current" until the engine speed has reached the correct value.

   Note: Refer to Table 1 in this manual for the correct value.

   1. Start the Electronic Technician.

   2. Select the Machine ECM and then select “OK”.

   3. Select “Diagnostics” from the main menu.

   4. Select “Diagnostic Tests”.

   5. Select “Override Parameters”.

   6. Select “Main Pump Solenoid Current” and set the current to 0.0 amp.

   7. Select “Main Pump Power Shift Solenoid Current” and set the current to 0.8 amp.

   8. Select “Main Pump Solenoid Current” and set the current to 0.8 amp.

   9. Select “Travel Pilot Solenoid Current Override” and set the current to 0.8 amp.

   10. Select the “Main Pump Power Shift Pressure Solenoid Current” and slowly decrease by 0.05 amp until the engine speed is 15 rpm above the "Target Engine Speed" from Table 1.

   11. Then adjust the “Main Pump Power Shift Pressure Solenoid Current” by 0.01 amp until the "Target Engine Speed" from Table 1 has been met.

       Note: Perform Step 3.k with a fully depressed travel pedal and the bucket in the full Bucket Open position.

       Note: Pay attention to the engine oil temperature and the engine water temperature.

       Note: If the load is too high, or if the load rises too fast the engine will stop running.

4. Verify the transmission output speed in Cat ET and the main pump pressure at pressure tap (1). Compare to Illustration 1 for MH3022 and MH3024 (FB71-UP) machines and Illustration 2 for MH3024 (FM41-UP, FB51-UP) and MH3026 machines.

5. Disable all overrides, release the travel pedal and joystick.

6. If the transmission output speed is not within tolerances, then pump performance or engine performance are out of specifications. To isolate whether the following components are performing properly (engine, main pump, main valve block, and travel motor ), the flow from the main pump will need to be measured with a flow meter. Perform Testing and Adjusting, "Main Pump - Test (Test with Flow Meter)".