Troubleshooting - Craftsman 16781 - Professional 80 Gal. Vertical Air Compressor Owner's Manual

_Risk of Unsafe Operation. Unit cycles automatically when
power is on. When servicing, you may be exposed to
voltage sources, compressed air, or moving parts. Before servicing unit
unplug or disconnect electrical supply to the air compressor, bleed tank of
pressure, and allow the air compressor to cool
PROBLEM
Excessive
tank pressure
- safety valve
pops off
Air leaks at
fittings
Air leaks at or
inside check
valve
Air leaks at
pressure switch
release valve
Air leaks in air
tank or at air
tank welds
Air leaks
between head
and valve plate
Pressure
reading on
the regulated
pressure gauge
(if equipped)
drops when an
accessory is
used
Air leak from
safety valve
CAUSE
Pressure switch does
not shut off motor when
compressor reaches "cut-
out" pressure.
Pressure switch "cut-out"
too high.
Tube fittings are not tight
enough.
Check valve seat
damaged.
Defective pressure switch
release valve.
Defective air tank.
Leaking seal.
It is normal for "some"
3ressure drop to occur.
CORRECTION
Move On/Auto/Off lever to the "Off"
position, if the unit does not shut off
contact a Trained Service Technician.
Contact a Trained Service Technician.
Tighten fittings where air can be
heard escaping. Check fittings with
soapy water solution. DO NOT OVER
TIGHTEN.
A defective check valve results in
a constant air leak at the pressure
release valve when there is pressure
in the tank and the compressor is
shut off. Replace check valve. Refer
the "To Replace or Clean Check
Valve" in the Service and Adjustments
section.
Contact a Trained Service Technician.
Air tank must be replaced. Do not
repair the leak.
_Risk of Bursting.
Be not drill into,
weld or otherwise modify air tank
or it will weaken. The tank can
rupture or explode.
Contact a Trained Service Technician.
If there is an excessive amount of
pressure drop when the accessory
is used, adjust the regulator as
instructed in the Operation section.
NOTE: Adjust the regulated pressure
under flow conditions (while
accessory is being used).
Possible defect in safety Operate safety valve manually by
valve, pulling on ring. If valve still leaks, it
should be replaced.
21ENG 1000002023