PIN AS 1189932 - Caterpillar

Required Tools
Illustration 1 g01089423
Tooling (A)
Illustration 2 g01784963
This tooling group is used to test the pressure in the pilot manifold.
Table 2
Tool Item Part Number Description Qty
A A1 8T-0856 Pressure Gauge
(0 to 6,000 kPa (0 to 870 psi)) 1
A2 6V-3989 Fitting 1
A3 6V-4143 Quick Connect Coupler 2
A4 177-7860 Hose As 1
F F1 6V-3965 Fitting 1
F2 3J-1907 O-Ring Seal 1 Preliminary Test
Start the engine. Place the hydraulic lockout lever in the UNLOCKED position.
Position the implements 1 m (3.3 ft) from the ground.
Shut off the engine by turning the start switch to the OFF position. When the engine has stopped, return the start switch to the ON position.
Move the joysticks in order to lower the implements. When the accumulator circuit is functioning properly, there will be enough stored energy for approximately 1 minute after a power loss in order to lower the implements to the ground safely.
If the preliminary test fails and the implements are unable to be lowered to the ground safely after a power loss, proceed to test the accumulator circuit. Refer to "Testing the Accumulator (Nitrogen Gas Charge)". Testing the Accumulator (Nitrogen Gas Charge)
Note: Some accumulators do not have a charge pressure port. This type of accumulator cannot be recharged. The accumulator must be replaced. Replacement accumulators are equipped with a charge pressure port.
Illustration 3 g03332567
Accumulator
(1) Charging port cap
Refer to Special Instruction, REHS5464, "Accumulator Discharging and Charging Procedures" for the testing and charging procedure. Note: If the pressure reading is within the specifications of Table 1, continue to test the operation of the check valve within the pilot manifold. Refer to "Testing the Check Valve (Main Control Valve)".Testing the Check Valve (Main Control Valve)
Illustration 4 g03332568
Main control valve
(2) Check valve If check valve (2) does not close properly during a loss of pilot pressure, the accumulator precharge pressure will exhaust before being able to provide lowering of the implements.Note: Make sure that the accumulator has a proper nitrogen gas charge before attempting to test check valve (2). An improperly charged accumulator may give indications of a problem with check valve (2).
Stop the engine. Release the pressure from the pilot hydraulic system. Refer to Testing and Adjusting, "Hydraulic System Pressure - Release".
Illustration 5 g03332569
Main control valve
(3) Pp port
Connect a 6895 kPa (1000 psi) pressure gauge to port "Pp" (3) on the main control valve. Use tooling group (A) and tooling group (F).
Start the engine and place the hydraulic lockout lever in the UNLOCKED position.
Shut off the engine by turning the start switch to the OFF position. When the engine has stopped, return the start switch to the ON position.
After the power loss, the accumulator will still have pilot system pressure. Use the stopwatch to observe the pilot pressure. The pilot pressure should stay above 1035 kPa (150 psi) for 1 minute. The pressure ensures that enough stored energy is available to lower the implements to the ground. Note: When, the pilot pressure in the accumulator is approximately 860 kPa (125 psi) the pressure will suddenly drop