LENS 5A9528 - Caterpillar

Probable Cause
Insufficient system pressure
Brake components have failed.
Steering clutch and brake control valve
Proportional solenoid valveRecommended Actions
If the brakes are applied and the machine does not slow down or if the machine does not stop, follow this procedure.The brakes are engaged with spring force. Hydraulic pressure is required to disengage the brakes. If hydraulic pressure is lost, the brakes fully engage due to the action of the spring force.Initially, a check of the brake pressure guides the diagnosis of the symptom to the brakes or to the steering clutch and brake control valve.If the brake pressure is correct, then the steering clutch and brake control valve is eliminated as the probable cause of the symptom. Thus, the brakes are the probable cause.If the brake pressure is not correct, then the steering clutch and brake control valve is the probable cause of the symptom. If the brake pressure is corrected and the symptom still exists, then the brakes could be the second contributor of the symptom.Insufficient Pressure Oil To The Brakes
Check the brake pressure.The brakes are engaged by spring force. The brakes are released by pressure oil which is sent from the steering clutch and brake control valve to the brakes. Therefore, insufficient pressure oil to the brakes is a probable cause of the symptom.ReferenceFor D5R2 models refer to Specifications, Systems Operation/Testing and Adjusting, UENR4119, "Steering Clutch and Brake Pressure - Test".ReferenceFor D6R2 models refer to Specifications, Systems Operation/Testing and Adjusting, UENR4109, "Steering Clutch and Brake Pressure - Test".Expected Results
The pressure is correct.Results
OKAY: Since the pressure at the steering clutch and brake control valve is correct, the brake control valve is eliminated as the cause of the symptom. The probable cause of the symptom is the brakes. Proceed to "Brake Components Have Failed".
NOT OKAY: The brakes are engaged by spring force. The brakes are released by pressure oil which is sent from the steering clutch and brake control valve to the brakes. Therefore, high-pressure oil from the steering clutch and brake control valve to the brakes is a probable cause of the symptom. Proceed to "Steering Clutch And Brake Control Valve".Brake Components Have Failed
Check the brakes.The brake pressure is correct and the engagement of the transmission clutches is correct. The brakes are the probable cause of the symptom.
Disassemble the brakes and check the following components of the brakes for failure:
Brake housing
Reaction plate
Brake pistons
Belleville springs
Stationary ring gear
Seals
Splines
Friction discs
Brake plates
Shuttle valve
Replace any damaged components, if necessary.
Calibrate the brakes.
ReferenceFor D5R2 models refer to Specifications, Systems Operation/Testing and Adjusting, UENR4119, "Calibration".ReferenceFor D6R2 models refer to Specifications, Systems Operation/Testing and Adjusting, UENR4109, "Calibration".Expected Results
The brake components are repaired or replaced. The original symptom is resolved.Results
OKAY: The brake components are repaired or replaced. The original symptom is resolved.
Stop.
NOT OKAY: The probable causes that were analyzed in this procedure did not identify the cause of the symptom. Use the information from the original symptom to troubleshoot. Proceed to "Steering Clutch And Brake Control Valve".Steering Clutch And Brake Control Valve
Disassemble the steering clutch and brake control valve and inspect