HOSE AS. 2531502 - Caterpillar

Illustration 5 g06280405
(3) Adjustment screw for margin pressure (Front Pump)
(4) Locknut
(5) Adjustment screw for high-pressure cutoff (Front Pump)
(6) Locknut
Loosen locknut (4) while you hold adjustment screw (3) in place.
Turn adjustment screw (3) clockwise to increase the margin pressure. Turn adjustment screw (3) counterclockwise to decrease the margin pressure.
Repeat Step "Test Procedure - Margin Pressure" to check the margin pressure.
If the margin pressure is 2500 150 kPa (365 22 psi), tighten locknut (4). Make sure that you hold adjustment screw (3) in place.
Check the margin pressure again. If the margin pressure is within the specified limit, the adjustment procedure is complete.Adjustment Procedure - High-Pressure Cutoff
Remove the floor plate in front of the operators seat in the cab.
Illustration 6 g06280405
(3) Adjustment screw for margin pressure (Front Pump)
(4) Locknut
(5) Adjustment screw for high-pressure cutoff (Front Pump)
(6) Locknut
Loosen locknut (6) while you hold adjustment screw (5) in place.
Turn adjustment screw (5) clockwise to increase the cutoff pressure. Turn adjustment screw (5) counterclockwise to decrease the cutoff pressure.
High-pressure cutoff should be 28500 500 kPa (4150 75 psi).
After the pressure is adjusted within the specified limit, tighten locknut (6). Make sure that you hold adjustment screw (5) in place.
Check the cutoff pressure again. If the pressure is within the specified limit, the adjustment procedure is complete.Test Preparation - Rear Pump
Move the machine to a smooth horizontal location.
Place the steering control lever in the NEUTRAL position.
Engage the parking brake.
Lower the attachments to the ground.
Stop the engine.
Turn the key to the ON position, but do not start the engine.
Verify that the implement lockout switch is in the UNLOCKED position.
To relieve any pressure that may be present in the implement hydraulic system, move the control levers through the full range of travel several times.
Make sure that the pressure in the entire hydraulic system has been released.
Turn the key to the OFF position.
Remove the floor plate from the machine.
Illustration 7 g06280426
Disconnect hose (2) from the left-hand pump. Cap hose (2) with Tooling (T2).Note: Leave the pump controller for the left-hand pump vented to the atmosphere.
Attach Tooling (T1) to pressure taps (HA) and (HLSB).
Replace the floor plate making sure not to damage the test equipment.Test Procedures - Rear Pump
Test Procedure - Margin Pressure
Start the engine. Warm the hydraulic oil to a minimum temperature of 65° C (150° F).
Operate the engine at HIGH IDLE.
With the implement control handles in the NEUTRAL position, record the pressure at pressure tap (HA). The rear implement pump discharge pressure should be greater than 1800 kPa (260 psi). This pressure is also known as low-pressure standby.
Move the bulldozer control lever to a position between 25% and 40% of the RAISE command. Take the difference between the pressure reading from the pump discharge pressure tap (HA) and the load sense pressure at pressure tap (HB). This difference is the margin pressure.
The margin pressure of rear pump should be 2500 150 kPa (365 20 psi) plus 175 75 kPa (25 11 psi). If the margin pressure is not within the specified limit,