TROUBLESHOOTING GUIDE
MAINTENANCE /
REP
AIR
TROUBLESHOOTING
OPERA
TION
ASSEMBL
Y
/
INST
ALLA
TION
SAFETY
/
SPECIFICA
TIONS
GETTING
ST
ARTED
10
OPERA
TION
SYMPTOM
POSSIBLE CAUSE(S)
CORRECTIVE ACTION
Low discharge pressure
1. Air leaks
1. Listen for escaping air. Apply soap solution to
all fittings and connections. Bubbles will appear
at points of leakage. Tighten or replace leaking
fittings or connections.
2. Leaking valves
2. Remove head and inspect for valve breakage,
weak valves, scored valve seats, etc. Replace
defective parts and reassemble.
Be sure that the old head gasket
is replaced with a new one each
time the head is removed.
3. Restricted air intake
3. Clean the air filter element.
4. Slipping belts
4. Loosen motor clamping bolts and move the motor
in a direction away from the compressor, being
sure that the motor pulley is perfectly aligned with
the flywheel. Tighten motor clamping bolts. The
belt should deflect about 1/2 inch under 5-lbs of
pressure. Do not “roll” belts over pulleys
5. Blown gaskets
5. Replace any gaskets proven faulty on inspection.
6. Low compression
6. Low pressure can be due to worn rings and
cylinder walls. Correction is made by replacing
the rings, cylinders, and pistons as required.
Overheating
1. Poor ventilation
1. Relocate the compressor to an area where an ample
supply of cool, clean, dry and well-circulated ari is
available.
2. Dirty cooling surfaces
2. Clean the cooling surfaces of pump and motor-engine.
Excessive belt wear
1. Pulley out of alignment
1. Realign engine pulley with compressor pulley
2. Belt too loose or too tight
2. Adjust tension (See Drive Belt Section).
3. Belt slipping
3. Adjust tension or replace belt (See Drive Belt
Section).
4. Pulley wobbles
4. Check for worn crankshaft, keyway or pulley bore
resulting from running the compressor or motor
with loose pulleys. Check for bent pulleys or bent
crankshaft.
Unit stalls
NOTE:
Electric models are
equipped with a pressure
switch that automatically turns
the motor OFF when the tank
pressure reaches a preset
level. After air is used from
the tank and drops to a preset
low level, the pressure switch
automatically turn the motor
back on.
1. Overloaded motor
1. Increase idle, refer to engine manual for details
2. Improper lubrication
2. See Lubrication section of manual.
3. Low oil level
3. Check oil level. Fill if necessary
4. Defective
check valve
4. Replace
Excessive noise (knocking)
1. Loose engine or compressor pulley
1. Tighten pulley clamp bolts and set-screws.
2. Lack of oil in crankcase
2. Check for proper oil level; if low, check for
possible damage to bearings. Dirty oil can cause
excessive wear.
3. Worn connecting rod
3. Replace connecting rod.
4. Worn piston pin bushing
4. Remove piston assemblies from the compressor
and inspect for excess wear. Replace excessively
worn piston pin or pistons, as required.
5. Worn bearings
5. Replace worn bearings and change oil.
