TEE AS 1488451 - Caterpillar

Illustration 1 g00893065
Place the steering frame lock in the LOCKED position.ReferenceFor more information about preparing the machine for troubleshooting, refer to the Service Manual module Testing and Adjusting, "Machine Preparation for Troubleshooting" for the machine that is being serviced.Pressure Test
Illustration 2 g00384713
Position the lift arms on the stands.
Illustration 3 g01185771
Front guard
Ensure that the engine start switch is in the OFF position. Remove the front guard in order to access the main control valve.
Illustration 4 g01187817
Main control valve (1) Pressure reducing valve (2) Pressure tap
Install a 8T-0850 Pressure Gauge from 1U-5481 Pressure Gauge Group or a 198-4240 Digital Pressure Indicator to pressure tap (2) on the main control valve.
Start the engine and warm the hydraulic oil to a normal operating temperature of approximately 49 to 65°C (120 to 150°F).
Run the engine at high idle. Raise the work tool until the lift cylinders are fully extended.
Observe the pressure gauge while the lift cylinders are fully extended.
The pressure reading should be at least 3515 345 kPa (510 50 psi).
When pressure is checked, position the lift arms on the lift arm supports.
If the pressure is correct, turn the engine start switch to the OFF position.
Release the hydraulic pressure. Refer to the Service Manual module Testing and Adjusting, "System Pressure - Release".
Remove the test equipment from the machine. Install the front guard.
Start the engine and remove the lift arms from the stands. Position the work tool on the ground and turn the engine start switch to the OFF position.
If the pilot oil pressure is not correct, turn the engine start switch to the OFF position.If the pressure reading is not within specifications, there are several possible causes:
The pressure reduction valve for the pilot system needs to be adjusted.
Pressure reduction valves for the pilot system need to be replaced or a seal may be damaged.
The piston pump (implement)(pilot) is worn. The pump needs to be replaced.
Proportional solenoids require calibration.
The valve for the dead engine lower is leaking.
A damaged seal in one of the proportional valves in the pilot valve
The solenoid valve (hydraulic lockout) may be leaking. There may be a damaged seal.In order to adjust the pressure reducing valve, refer to the instructions below on adjusting the pressure reducing valve.ReferenceFor information about replacing the Piston Pump (Implement)(Pilot), refer to the Service Manual module Disassembly and Assembly, "Piston Pump (Implement)(Pilot) - Remove" and Disassembly and Assembly, "Piston Pump (Implement)(Pilot) - Install".ReferenceFor additional information on calibrations for the operator monitor, refer to the Service Manual module Testing and Adjusting, "Position Sensor for the Electrohydrualic Control Levers (Operator Monitor) - Calibrate, Position Sensor for the Lift Linkage (Operator Monitor) - Calibrate, Position Sensor for the Tilt Linkage (Operator Monitor) - Calibrate, Position Sensor for the Joystick Control (Operator Monitor)