RAM-30 TON 1U7552 - Caterpillar

Illustration 3 g02452796
Main relief valve pressure tap is located behind the left rear access door.
Connect tooling (B2) 41,368 kPa (6,000 psi) pressure sensor to main relief valve pressure tap.Temporary Setting of the Signal Limiter Relief Valve
Illustration 4 g02374477
Main control valve
(1) Adjustment screw
(2) Locknut
(3) Adjustment screw
(4) Locknut
(5) Adjustment screw
(6) Locknut
(7) Main relief valve
(8) Load sensing signal limiter valve
Loosen locknut (6) on load sensing signal limiter valve (8).
Turn adjustment screw (5) on load sensing signal limiter valve (8) clockwise by one half turn.Note: LS cutoff pressure should now be higher than the main relief valve pressure.
Tighten locknut (6) load sensing signal limiter valve (8).Test Procedure
Start the engine.
Illustration 5 g02452604
Engine speed dial
Set the engine speed dial at "1".
Lower the left console.
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Power mode control button on the soft panel switch
Push down on the power mode control button to activate power mode.Note: The indicator light will be illuminated when power mode is activated.
Illustration 7 g02447036
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.
Illustration 8 g03722432
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.
Stall one of the following circuits on the machine to obtain a pressure reading:
Blade/Dozer Circuit
Stabilizer CircuitNote: These circuits are used because there are no line relief valves in these circuits.
Check the pressure at the main relief valve pressure tap.Note: Refer to Table 1 in this manual for the correct pressure.
If the main relief valve pressure is not correct, refer to the "Adjustment Procedure".Adjustment 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.
Loosen locknut (2) on main relief valve (7).
To avoid damage to the hydraulic components, do not turn the main relief valve adjustment screw into the stop.
Turn adjustment screw (1) main relief valve (7) clockwise to increase the pressure. Turn adjustment screw (1) main relief valve (7) counterclockwise to decrease the pressure.Note: A 1/4 turn of the adjustment screw will equal approximately 4000 kPa (580 psi).
Check the pressure at the main relief valve pressure tap.Note: Refer to Table 1 in this manual for the correct pressure.Note: Always make the final pressure adjustments on the pressure rise.
Tighten locknut (2) on main relief valve (7) to the specified torque.
Adjust load sensing signal limiter valve (8) to the correct pressure setting.Note: Refer to Testing and Adjusting, "Relief Valve (Signal Limiter) - Test and Adjust" in this manual for the adjustment procedure.Worksheet
Table 3
"Relief Valve (Main) - Test and Adjust"
Date: Machine Serial Number:
Machine Settings Engine Speed
Speed dial "5"
AESC switch OFF
Item Specification Actual
Main line relief pressure 41,000 + 1,000 kPa (5,947 + 145 psi)