TROUBLESHOOTING GUIDE
SYMPTOM
Low discharge pressure
Overheating
Excessive belt wear
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.
Excessive noise (knocking)
POSSIBLE CAUSE(S)
1. Air leaks
2. Leaking valves
3. Restricted air intake
4. Slipping belts
5. Blown gaskets
6. Low compression
1. Poor ventilation
2. Dirty cooling surfaces
1. Pulley out of alignment
2. Belt too loose or too tight
3. Belt slipping
4. Pulley wobbles
1. Overloaded motor
2. Improper lubrication
3. Low oil level
4. Defective
check valve
1. Loose engine or compressor pulley
2. Lack of oil in crankcase
3. Worn connecting rod
4. Worn piston pin bushing
5. Worn bearings
CORRECTIVE ACTION
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. Remove head and inspect for valve breakage,
weak valves, scored valve seats, etc. Replace
defective parts and reassemble.
time the head is removed.
3. Clean the air filter element.
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. Replace any gaskets proven faulty on inspection.
6. Low pressure can be due to worn rings and
cylinder walls. Correction is made by replacing
the rings, cylinders, and pistons as required.
1. Relocate the compressor to an area where an ample
supply of cool, clean, dry and well-circulated ari is
available.
2. Clean the cooling surfaces of pump and motor-engine.
1. Realign engine pulley with compressor pulley
2. Adjust tension (See Drive Belt Section).
3. Adjust tension or replace belt (See Drive Belt
Section).
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.
1. Increase idle, refer to engine manual for details
2. See Lubrication section of manual.
3. Check oil level. Fill if necessary
4. Replace
1. Tighten pulley clamp bolts and set-screws.
2. Check for proper oil level; if low, check for
possible damage to bearings. Dirty oil can cause
excessive wear.
3. Replace connecting rod.
4. Remove piston assemblies from the compressor
and inspect for excess wear. Replace excessively
worn piston pin or pistons, as required.
5. Replace worn bearings and change oil.
10
Be sure that the old head gasket
is replaced with a new one each