SECTION 7: TROUBLESHOOTING
CAS40P 40 CFM / 100 PSIG
PAGE - 60
®
An Oshkosh Corporation Company
Compressor will not start
(continued)
25a fuse blown
Check and replace fuse if necessary
(
Section 6.4.15
).
Compressor pressure switch
stuck
Replace; consult Service Department for
reset instructions.
Diverter valve not operating
Check power and ground/replace valve.
Hydraulic motor stalled
Switch OFF and attempt to turn the motor
by hand to restart—replace if this fails.
Hydraulic pump failure
Replace.
Hydraulic relief valve set too low
Check with pressure gauge and reset.
Power unit speed is too low
Check and correct.
Hydraulic line obstructed
Check hoses for kinks, crimping, or dam-
age.
Low hydraulic oil level
Check and refill.
Compressor runs slow
Hose/connection leaks
Check for leaks or damage/repair (
Sec-
tion 6.4.14
and
Section 8.14
).
Low hydraulic flow/pressure
Check and reset.
Hydraulic motor or pump worn
Replace.
Low hydraulic oil level
Check and refill.
Hydraulic relief valve set too low
Check and reset.
Power speed too slow
Check and correct.
Hydraulic oil line restriction
Check for blockages, kinks, or other
obstructions.
Priority valve set too low
Reset.
Compressor runs hot
Cooling fan not operating
Check/power ground to fan motor (
Figure
4-4
).
Faulty relay
Check for presence of power - if present,
replace relay.
20A circuit breaker tripped
Replace 20A breaker (
Section 6.4.15
).
Replace fan assembly, if faulty.
Continued on next page
7.2 TROUBLESHOOTING GUIDE
MALFUNCTION/FAULT
POSSIBLE CAUSE
CORRECTIVE ACTION
Manual #99905382 Rev 02
(JUNE 2018)
