MH3022, MH3024 and MH3026 Material Handlers Hydraulic System Caterpillar

Specification

Introduction

This procedure is utilized to test the line relief for the hammer circuit.

The line relief valves limit the maximum line pressure in each circuit.

Required Tools

Illustration 1	g02726620

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 2	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. Lower the stabilizers and the blade tip.

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

10. Stop the engine.

11. Release the pressure in the hydraulic system.

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

12. Raise the left console.
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    Illustration 3	g03857086
    Signal pressure taps are located behind the left front access door

13. Connect tooling (B2) 60,000 kPa (8,702 psi) pressure sensor to the load sensing signal pressure tap.
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    Illustration 4	g03722485
    Service connector on the right side of cab behind the seat

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

Temporary Setting of the Main Relief Valve

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Illustration 5	g03729304
Main control valve (1) Main relief valve (2) Load sensing signal limiter valve (3) Adjustment screw (4) Locknut (5) Adjustment screw (6) Locknut

1. Loosen locknut (6) on load sensing signal limiter valve (2).

2. Turn adjustment screw (5) of load sensing signal limiter valve (2) clockwise by one half turn.

3. Tighten locknut (6) on load sensing signal limiter valve (2).

4. Remove the cap from main relief valve (1).

5. Loosen the locknut on main relief valve (1).

6. Turn the adjustment screw clockwise on main relief valve (1) by one quarter turn.

7. Tighten the locknut on main relief valve (1).

8. Install the cap onto main relief valve (1).

Work Tool Setup (Monitor Adjustment)

The following procedure will allow for a two-way work tool to be programmed within the machine ECM using the monitor.

This section outlines the procedures for adjusting a tool by utilizing the monitor.

1. Place the engine start switch in the ON position. Do not start the engine.
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   Illustration 6	g03722433

2. The "Home" screen of the monitor is displayed when the key switch for the machine is turned to the ON position. Press the "Menu" key to display the main menu options.
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   Illustration 7	g03724611

3. Use the arrows to select "Service Mode" from the "Main Menu". Press the "OK" key.

4. Input the password "FFF2". Press the "Enter" key.

   Note: The soft switch key pad can be used to enter the desired numbers.

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   Illustration 8	g03741236

5. Select "Tool Program" from the "Service" menu. Press the "OK" key.
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   Illustration 9	g03741237

6. The ten programmable tools are now displayed. Use the arrows to select the desired tool for programming. Press the "OK" key.

   Note: Press the Save key on this screen to save the parameters to USB memory.

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   Illustration 10	g03742042

7. Use the arrow keys to highlight the parameter. Press the "OK" key to change the default value.

8. Use the arrow keys to change the value or designation of the parameter. Press the "OK" key to enter the change.

   Note: The soft switch key pad can be used to enter a desired number value.

   Note: If the selected solenoid is "Two Way", the parameters for the "Back" direction ("B⇒A") and the "Front" direction ("A⇒B") will be displayed.

9. The following parameters can be modified for each of the tools.

   • Name of the tool

   • Flow direction "Two Way"

   • 100 L/min (26 US gpm)flow for the front direction ("A⇒B")

   • 100 L/min (26 US gpm) flow for the back direction ("B⇒A")

   • Maximum pressure for the front direction ("A⇒B")

   • Maximum pressure for the back direction ("B⇒A")

10. Select the desired parameter with the up arrow or the down arrow.

11. Press the "OK" key to enter the change.

12. Change the values with the right arrow or the left arrow.

13. Press the "OK" key to enter the change.

14. Raise the left armrest. Wait for one second. Lower the left armrest. Alternatively, activate the Implement Lockout and then deactivate the Implement Lockout after a few seconds.

Test Procedure

1. Start the engine.

2. Set the engine speed dial at "10".
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   Illustration 11	g02446738
   Power mode control button on the soft panel switch

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

4. Disable the automatic engine speed control through the monitor by pressing the programmable button.
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   Illustration 13	g03722432
   Hydraulic modulation switch on left joystick

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   Illustration 14	g06174873
   Hydraulic modulation medium mode (monitor display)

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

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

7. Start Cat (ET).

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

   2. Select “Service” from the main menu.

   3. Select “Service Procedures”.
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      NOTICE
      Creating main pump pressure higher than 38,000 kPa (5,512 psi) for more than five seconds may damage the machine.

   4. Select "Line and Main Relief Adjustments".

      Note: This selection provides a permanent flow of about 40 L/min (11 US gpm) from the main pump without any margin pressure control. The multi combined valve (MCV) load sensing cutoff valve pressure is set to maximum and the MCV line relief pressure is set to 25,000 kPa (3,626 psi). Cat (ET) also allows the main pump pressure limit to be raised to provide high pressure of about 43,000 kPa (6,237 psi).

8. Lower the left console.
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   Illustration 15	g03741280
   Joystick (thumb slider)

9. Operate the hammer.

   1. For pressure on port "A", move the thumb slider on the left joystick to the left position and read the pressure on the pressure gauge that is connected to the load sensing signal pressure tap. Refer to Table 1 for the correct pressure.

   2. For pressure on port "B", move the thumb slider on the left joystick to the right position and read the pressure on the pressure gauge that is connected to the load sensing signal pressure tap. Refer to Table 1 for the correct pressure.

10. If the line relief valve pressure is not set to the proper specification, refer to the "Adjustment Procedures".

Adjustment Procedures

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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.

Illustration 16	g06174856
(7) Relief valve (port B) (8) Plug (9) Adjustment screw (10) locknut (11) Multi combined valve (12) Relief valve (port A)

Adjustment Procedure (Port A)

1. Stop the engine.

2. Release the pressure in the hydraulic system.

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

3. Raise the left console.

4. Remove the cap from line relief valve (12).
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   NOTICE
   To avoid damage to the hydraulic components, do not turn the main relief valve adjustment screw into the stop.

5. Turn the adjustment screw on the line relief valve clockwise to increase the pressure. Turn the adjustment screw on the line relief valve counterclockwise to decrease the pressure.

   Note: A quarter turn of the adjustment screw will equal approximately 4,000 kPa (580 psi).

6. Repeat the "Test Procedure" until the line relief pressure has been met. Refer to Table 1 for the correct pressure.

   Note: Always make the final pressure adjustments on the pressure rise.

7. Install the cap onto the line relief valve.

8. Once the line relief pressure has been met, click the "Next" button to return to normal operation in Cat (ET).

9. Perform the auto calibration procedure, "Multi-Function - Auxiliary Calibration" in Cat (ET).

   Note: The line relief valve for port "A" is an electronically controlled valve.

Adjustment Procedure (Port B)

1. Stop the engine.

2. Release the pressure in the hydraulic system.

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

3. Raise the left console.

4. Remove plug (8) from line relief valve (7).

5. Loosen locknut (10).
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   NOTICE
   To avoid damage to the hydraulic components, do not turn the main relief valve adjustment screw into the stop.

6. Turn adjustment screw (9) on the line relief valve clockwise to increase the pressure. Turn adjustment screw (9) on the line relief valve counterclockwise to decrease the pressure.

   Note: A quarter turn of the adjustment screw will equal approximately 4,000 kPa (580 psi).

7. Repeat the "Test Procedure" until the line relief pressure has been met. Refer to Table 1 for the correct pressure.

   Note: Always make the final pressure adjustments on the pressure rise.

8. Hold adjustment screw (9) and tighten locknut (10) to the specified torque.

9. Install plug (8) onto the line relief valve.

10. Once the line relief pressure has been met, click the "Next" button to return to normal operation in Cat (ET).

11. Adjust main relief valve (1) to the original setting.

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

12. Adjust load sensing signal limiter valve (2) to the original setting.

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