17
TROUBLESHOOTING
PROBLEM
POSSIBLE CAUSE
CORRECTIVE ACTION
Low discharge
pressure
(Continued)
4. Blown gaskets
4. Replace any gaskets proven faulty on
inspection.
5. Leaking or damaged
valves
5. Remove head and inspect for valve breakage,
misaligned valves, damaged valve seats, etc.
Replace defective parts and reassemble.
CAUTION
Unit care and maintenance.
Install a new
head gasket each time the head is removed.
Excessive noise
(knocking)
1. Loose motor pulley or
flywheel
1. Tighten pulley / flywheel clamp bolts and set-
screws.
2. Loose fasteners on pump
or motor
2. Tighten fasteners.
3. Lack of oil in crankcase
3. Check for proper oil level; if low, check for
possible damage to bearings. Dirty oil can
cause excessive wear.
4. Worn connecting rod
4. Replace connecting rod. Maintain oil level and
change oil more frequently.
5. Worn piston pin bores
5. Remove piston assemblies from the
compressor and inspect for excess wear.
Replace excessively worn piston pin or pistons,
as required. Maintain oil level and change oil
more frequently.
6. Piston hitting the valve
plate
6. Remove the compressor head and valve plate
and inspect for carbon deposits or other foreign
matter on top of piston. Replace head and
valve plate using new gasket. See Lubrication
section for recommended oil.
7. Noisy check valve in
compressor system
7. Replace check valve.
Risk of Explosion.
Do not
disassemble check valve with air
pressure in tank.
DANGER
Large quantity of oil
in the discharge air
NOTE: In an oil-
lubed compressor
there will always be
a small amount of
oil in the air stream.
1. Worn piston rings
1. Replace with new rings. Maintain oil level and
change oil more frequently.
2. Compressor air intake
restricted
2. Clean or replace filter. Check for other
restrictions in the intake system.
3. Excessive oil in
compressor
3. Drain down to full level.
4. Wrong oil viscosity
4. Use Mobil 1
®
10W-30 or full synthetic.
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