CYLINDER 9R8639 - Caterpillar

Test Preparation
Clear all personnel from the machine and from the area around the machine.
Start the engine.
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Engine speed dial
Set the engine speed dial at "10".
Lower the left console.
Position the machine on level ground. Check the visibility and adjust the mirrors for the best vision close to the machine.
Fully depress the service brake pedal until the service brake pedal locks mechanically.
Increase the hydraulic oil temperature to 46° to 60° C (115° to 140° F).
Lower the rail axles in order that all tires are fully off the ground, and shunt the road mode.
Fully extend the bucket cylinder and place the bucket on the ground.
Stop the engine.
Release the pressure in the hydraulic system.Note: Refer to Testing and Adjusting, "System Pressure - Release".
Raise the left console.
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Medium pressure tap is located below the seat in the second cab
Attach Tooling (T1) 34,450 kPa (5,000 psi) pressure sensor to the medium pressure tap.Test Procedure
Start the engine.
Set the engine speed dial at "10".
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Power mode control button located on the soft panel switch
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.
Lower the left console.
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Automatic Engine Speed Control (AESC) as displayed on the programmable function key in the monitor.
Disable the automatic engine speed control through the monitor by pressing the programmable button.
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Hydraulic modulation switch on left joystick
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Hydraulic modulation aggressive mode (monitor display)
Select the hydraulic modulation mode as aggressive. Press the lower front switch on the left joystick to select the hydraulic modulation mode.
The air conditioning should be turned off for the following test.
Operate the medium pressure attachment against the end position of the cylinders and hold.
Check the pressure at the medium pressure tap. Refer to Table 1 for the correct pressure.
If the line relief valve pressure is not set to the proper specification, proceed to the "Adjust Procedure"adjust the pressure at the appropriate relief valve.Adjust Procedure
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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Medium pressure manifold
(1) Relief valve (LS cutoff) for the medium pressure function
Loosen the locknut on relief valve (2).
Stall the attachment and hold.
Turn the adjustment screw on relief valve (2) clockwise in order to increase the pressure. Turn the adjustment screw on relief valve (2) counterclockwise in order to decrease the pressure.Note: Pressure will increase 4,000 kPa (580 psi) when the adjustment screw is moved clockwise by one turn.Note: Always make the final pressure adjustment on the pressure rise.
While the adjustment screw on relief valve (2) is being held, tighten the locknut to the specified torque.