Operation and maintenance manual

Troubleshooting Symptoms Charts QSB4.5 and QSB6.7
Page TS-4 Section TS - Troubleshooting Symptoms
Air Compressor Cycles Frequently
Cause Correction
STEP 1
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 the OEM service manuals.
OK
Go To Next Step
STEP 2
Carbon buildup is excessive in the air discharge
line, check valve, or cylinder head
.............
Check for carbon buildup. Replace the air
compressor discharge line, if necessary. Refer to
Section 7.
OK
Go To Next Step
STEP 3
Air compressor pumping time is excessive
.............
Replace the desiccant cartridge on the Turbo/CR
2000 air dryer. Refer to the OEM service manual.
Check the air compressor duty cycle. Install a
larger air compressor, if necessary. Refer to an
Authorized Cummins Repair Facility.
OK
Go To Next Step
STEP 4
Contact a Cummins® Authorized Repair Facility