MH3049 Material Handler Hydraulic System Caterpillar

Introduction

When the main control valve has been serviced or the hydraulic oil has been replaced, use the following procedure to remove air from the hydraulic system.

Machine Preparation

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

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NOTICE
To avoid system damage, make sure that the hydraulic pump is properly filled with hydraulic oil before start-up.

2. Start the engine.

3. Place the hydraulic activation control lever in the UNLOCKED position.

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Illustration 1	g03095556
Engine speed control "Max Speed" as displayed on the programmable function key on the monitor.

4. Press button "A" on the monitor to set the engine speed at "Max Speed".

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Illustration 2	g03094559
Parking brake control button located on the soft panel switch

5. Push down on the parking brake control button in order to de-activate the parking brake.

   Note: The green indicator light will be illuminated when the parking brake is de-activated.

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Illustration 3	g03094697
Swing brake control button located on the soft panel switch

6. Push down on the swing brake control button in order to de-activate the swing brake.

   Note: The green indicator light will be illuminated when the swing brake is de-activated.

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

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Illustration 4	g03094816
Stabilizer lower control button located on the soft panel switch

8. Push down on the stabilizer control button in order to lower the stabilizer to the ground.

   Note: All tires must be fully off the ground.

9. Lower the work tool to the ground.

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Illustration 5	g03377820
Parking brake control button located on the soft panel switch

10. Push down on the parking brake control button in order to activate the parking brake.

    Note: The red indicator light will be illuminated when the parking brake is activated.

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Illustration 6	g03377798
Swing brake control button located on the soft panel switch

11. Push down on the swing brake control button in order to activate the swing brake.

    Note: The red indicator light will be illuminated when the swing brake is activated.

Adjustment 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.

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Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the work tools have been lowered to the ground, and the oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.

Upper Control Valve

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Illustration 7	g03152299
View of upper main control valve (1) Plug (boom cylinder - retract) (2) Plug (stick cylinder - retract) (3) Plug (grapple cylinder - retract) (4) Plug (boom cylinder - retract)

1. Slowly loosen the plug for the appropriate valve.

   Note: Only purge one valve at a time

2. Slowly operate the joysticks for the circuit that is being purged without fully extending the cylinders or without operating at full speed.

3. When oil begins to flow around the plug, tighten the plug for the appropriate shock reducing valve to the specified torque.

4. Repeat Steps 1 through 3 for each circuit.

Lower Control Valve

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Illustration 8	g03152301
View of lower main control valve (5) Plug (right front travel motor) (6) Plug (left front travel motor) (7) Plug (left rear travel motor) (8) Plug (right rear travel motor)

1. Slowly loosen the plug for the appropriate travel valve.

   Note: Only purge one parking brake shock reducing valve at a time

2. Slowly operate the travel pedal if the forward direction and the reverse direction.

3. When oil begins to flow around the plug, tighten the plug for the appropriate travel valve to the specified torque.

4. Repeat Steps 1 through 3 for each circuit.