Symptom Tree t005
| Cause | Correction |
|---|
|
Air system leaks |
Block the vehicle wheels and check the air system for leaks with spring brakes applied and released. Check for leaks from the air compressor gaskets and the air system hoses, fittings, tanks, and valves. Refer to Procedure 012-019 in Section 12 and the OEM service manual. Check for air system leaks in the aftertreatment purge air actuator. Refer to Procedure 011-065 in Section 11. |
 |
|
Air governor is malfunctioning or not set correctly |
Check the air governor for correct operation. Some OEM installations may not utilize an air governor, therefore frequent cycling may be expected and normal. Refer to the OEM service manual. |
|
|
Air system component is malfunctioning |
Check the operation of check valves, alcohol evaporators, air dryers, and other OEM-installed air system components. Refer to the OEM service manual. Check the operation of the air shutoff valve. |
|
|
Carbon buildup is excessive in the air discharge line, downstream air valves, or cylinder head |
Check for carbon buildup. Replace the air compressor discharge line, cylinder head, or air compressor. Check the turbocharger for oil leaks. Check the intake tube for oil. Refer to Procedure 012-003 in Section 12. Check the turbocharger for oil leaks. Check the intake tube for oil. Refer to |
|
|
Air dryer outlet check valve is sticking |
Lubricate or replace the air dryer outlet check valve assembly. Refer to the OEM service manual. |
