TUBE AS 2473406 - Caterpillar

Probable Causes
Retarder Control Valve
Parking and Secondary Brake Control Valve
Slack Adjuster
Brake Lines
Service BrakeRecommended Actions
The Automatic Control is controlled by the Brake ECM. The function of the ARC system allows the operator to maintain a constant speed of the truck during long downgrades. The ARC also functions in order to maintain constant speed of the engine during long downgrades. The ARC also provides protection for the engine in overspeed conditions. The ARC system signals the Engine ECM to engage the Service brake.Retarder Control Valve
Perform the following test in order to troubleshoot the retarder air control valve. Refer to Testing and Adjusting, KENR8738, "Service Brakes and Retarder System Pressure - Test".Refer to Testing and Adjusting, KENR8738, "Service Brakes and Retarder System Leakage - Check".Refer to Testing and Adjusting, KENR8738, "Braking System Troubleshooting".Parking and Secondary Brake Control Valve
Refer to Testing and Adjusting, KENR8738, "Braking System Troubleshooting".Refer to Testing and Adjusting, KENR8738, "Parking and Secondary Brake Release System Leakage - Check".Refer to Testing and Adjusting, KENR8738, "Brake System Pressure - Test and Adjust".Slack Adjuster
ReferenceRefer to Testing and Adjusting, KENR8738, "Slack Adjuster - Test and Adjust".ReferenceRefer to Testing and Adjusting, KENR8738, "Brake System".ReferenceRefer to Testing and Adjusting, KENR8738, "Service Brakes and Retarder System Pressure - Test".Brake Lines
Check the lines and clamps. Damaged lines with leaks can normally be seen. Lines that have no visual leaks can soften during operation. The soft areas of the lines can become kinked or crushed and these areas of the hose can cause a restriction in fluid flow. Hoses can also crack after a period. The inside of a hose can deteriorate, and the loose particles of the hose can cause a restriction of fluid flow. Ensure that all hoses and lines are routed correctly. Service Brake
Refer to the following procedures when troubleshooting the service brakes. ReferenceRefer to Testing and Adjusting, KENR8738, "Operational Checks".ReferenceRefer to Testing and Adjusting, KENR8738, "Brake System".ReferenceRefer to Testing and Adjusting, KENR8738, "Service Brake Discs - Check (Standard)".ReferenceRefer to Testing and Adjusting, KENR8738, "Service Brake Discs - Check (Extended Life)".ReferenceRefer to Testing and Adjusting, KENR8738, "Service Brakes and Retarder System Pressure - Test".