MH3049 Material Handler Hydraulic System Caterpillar

Specification

Introduction

The IQAN monitor has a "Warm Up Speed" function that is used to warm the hydraulic fluid to 13° C (55° F). The warming manifold allows hydraulic oil to cycle through the main control valves. This test will verify that the warming relief valve is set to the correct pressure.

Note: This test must be performed when the ambient temperature and the hydraulic fluid are both below 13° C (55° F).

Note: Prior to performing this test, the Testing and Adjusting, "Hydraulic System Pressure - Test and Adjust (Anti-Cavitation)" must be performed.

Required Tools

Illustration 1	g02571852
Tooling (A) 198-4240 Digital Pressure Indicator Gp

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 2	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 3	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 4	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 5	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.

9. Lower the work tool to the ground.

10. Place the hydraulic activation control lever in the LOCKED position.

11. Stop the engine.

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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 attachments have been lowered, 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.

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NOTICE
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the machine. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Caterpillar Tools and Shop Products Guide", for tools and supplies suitable to collect and contain fluids in Caterpillar machines. Dispose of all fluids according to local regulations and mandates.

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Illustration 6	g03166705
Load sensing signal pressure tap is located behind the right side access door.

12. Connect tooling (A2) 0 to 41,368 kPa (0 to 6,000 psi) pressure sensor to the load sensing signal pressure tap.

Test Procedure

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

1. Start the engine.

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Illustration 7	g03230516
Engine speed control "Warm Up Speed" as displayed on the programmable function key on the monitor.

2. Press button "C" on the monitor in order to engage the "Warm Up Speed".

3. Check the pressure at the load sensing signal pressure tap.

   Note: Refer to Table 1 in this procedure for the correct pressure.

4. If the signal pressure is not correct, refer to the "Adjustment Procedure".

Adjustment Procedure

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Illustration 8	g03230436
View of warming manifold and relief valve (1) Load sensing signal limiter valve

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

2. Turn the adjustment screw until the pressure reading at the load sense pressure tap has reached the correct pressure.

   Note: Refer to Table 1 in this procedure for the correct pressure.

   Note: Turn the adjustment screw clockwise in order to increase the pressure. Turn the adjustment screw counterclockwise in order to decrease the pressure.

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

3. While the adjustment screw on load sensing signal limiter valve (1) is being held, tighten the locknut.

4. Verify that the pressure is within specification.