ELBOW 0057734 - Caterpillar

Illustration 4 g03870899
(P5) Implement pump discharge pressure
(P6) Load sensing pressure
Attach Tooling (A) to load sensing pressure tap (P6).
Attach Tooling (A) to pump discharge pressure tap (P5).Test Procedure - Margin Pressure
Perform steps in the "Test Preparation - Margin Pressure" section.
Start the engine. Warm the hydraulic oil to 55° 10°C (131° 18°F).
Operate the engine at HIGH IDLE.
Move the bulldozer control lever to a position between 25% and 33% of the RAISE command. Read the differential pressure on Tooling (A) while the blade is still rising. Record this pressure into Table 1 of the "Specifications". The margin pressure should be 1700 100 kPa (247 15 psi).
If, margin pressure is not correct, perform the steps in "Adjustment Procedure - Margin Pressure".Adjustment Procedure - Margin Pressure
Note: Adjustments to the flow compensator valve can be made on the machine.
Illustration 5 g01774475
Compensator Valve
(1) Flow Compensator Spool
(2) Locknut
(3) Adjustment screw for the Flow Compensator
(4) Nut
(5) Nut
(6) Adjustment screw for the Pressure Compensator
(7) Locknut
(8) Pressure Compensator Spool
Perform steps in the "Test Procedure - Margin Pressure".Note: The engine must be off before performing any adjustments to the pump, requiring several adjustments and engine restarts to obtain the required settings.
Remove nut (4).
Loosen locknut (2). Maintain the position of adjustment screw (6).
Turn adjustment screw (3) clockwise to increase the pressure setting. Turn adjustment screw (3) counterclockwise to decrease the pressure setting.Note: Turn adjustment screw (3) counterclockwise past the desired pressure setting. Then, turn adjustment screw (3) clockwise to the correct pressure setting. This method of adjusting the pressure setting eliminates any movement in the threads.
Tighten locknut (2) to a torque of 21 N m (185 lb in).Note: Do not allow adjustment screw (3) to rotate when locknut (2) is tightened.
Install nut (4). Tighten nut (4) to a torque of 21 N m (185 lb in).
Repeat "Test Procedure - Margin Pressure".Test Preparation - High-Pressure Stall
Perform steps in the "Test Preparation - Margin Pressure".Test Procedure - High-Pressure Stall
Perform steps in the "Test Preparation - High-Pressure Stall".
Start the engine. Warm the hydraulic oil to 55° 10°C (131° 18°F).
Operate the engine at HIGH IDLE.
Move the control lever to initiate a stall condition in the tilt cylinder.Note: Do not keep the control lever in a stalled condition for more than 10 seconds. Do not return to a stalled condition within 30 seconds of the prior stalled condition.
Read the pump discharge pressure at pressure tap (P5). Record this pressure into Table 1 of the "Specifications". The pressure reading at pressure tap (P5) should be 25210 450 kPa (3656 65 psi).
Read the load sensing pressure at pressure tap (P6). Record this pressure into Table 1 of the "Specifications". The pressure reading at pressure tap (P6) should be 22650 250 kPa (3285 36 psi).
If, the value that was obtained in Step 5 is not within specifications and the value that was obtained in Step 6 is not within specifications, perform the steps in "Adjustment Procedure - High-Pressure Stall".Adjustment Procedure - High-Pressure Stall
The load sensing relief valve is on the inlet