Operation and maintenance manual

QSB4.5 and QSB6.7 Troubleshooting Symptoms Charts
Section TS - Troubleshooting Symptoms Page TS-5
Air Compressor Noise is Excessive
Cause Correction
STEP 1
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 and cylinder head
assembly if necessary. Refer to Section 7.
OK
Go To Next Step
STEP 2
Air compressor is sending air pulses into the air
tanks
.............
Install a ping tank between the air dryer and the
wet tank. Refer to the manufacturer's instructions.
OK
Go To Next Step
STEP 3
Ice buildup in the air system components
.............
For all models, check for ice in low spots of the air
discharge line, dryer inlet, and elbow fittings. On
Holset® models, also check the Econ valve (if
equipped). Refer to the OEM service manual.
OK
Go To Next Step
STEP 4
Contact a Cummins® Authorized Repair Facility