Troubleshooting Chart - Craftsman 921.16477 Owner's Manual

Note: Troubleshooting problems may have similar causes and solutions.
PROBLEM
Excessive current draw
trips circuit breaker or
motor reset switch
Compressor stalls
Low discharge pressure
Compressor pump
knocking
Oil in discharge air
Overheating
Excessive belt wear
Compressor won't start
in cold temperatures
Air leaking through
bleeder valve after
compressor shuts off
TROUBLESHOOTING
POSSIBLE CAUSE
Low voltage/motor overload
Drive belt tension too tight
Restricted air passages
Low voltage to motor
Bad check valve
Seized pump
Air leaks
Leaking valves
Restricted air intake
Blown gaskets
Worn piston rings or cylinder
Loose motor pulley or pump
flywheel
Low oil level in pump crankcase
Excess carbon on valves or top of
piston
Worn piston rings or cylinder
Restricted air intake
Oil level too high
Poor ventilation
Dirty cooling surfaces
Restricted air passages
Pulley out of alignment
Improper belt tension
Pulley wobbles
Too much back pressure in tank
40W oil in crankcase
Compressor too cold
Dirty or defective check valve.
SOLUTION
Check that power supply is adequate and that compressor is on a
dedicated circuit.
Readjust belt tension.
Inspect and replace transfer tubes or the check valve, (see "To replace
or clean check valve" in the maintenance section).
Furnish adequate power.
Replace the check valve (see "To replace or clean check valve" in the
maintenance section).
Contact a Sears or other qualified service center.
Tighten or replace leaking fittings or connections. Do not overtighten.
Contact a Sears or other qualified service center.
Clean or replace air filter element(s).
Contact a Sears or other qualified service center.
Contact a Sears or other qualified service center.
Retighten pulley and flywheel. Check alignment.
Keep oil at proper level at all times.
Contact a Sears or other qualified service center.
Contact a Sears or other qualified service center.
Clean or replace the air filter element(s).
Reduce to proper level.
Relocate compressor to an area with cool, dry, well circulated air, at
least 12 in. from nearest wall.
Clean all cooling surfaces thoroughly.
Inspect and replace transfer tubes or the check valve, (see "To replace
or clean check valve" in the maintenance section).
Realign pulley with compressor flywheel.
Readjust.
Replace the pulley and check for a damaged crankshaft or flywheel.
Open petcock when starting motor.
Use synthetic, non-detergent air compressor oil.
Move compressor to a warmer location.
Replace or clean the check valve (see "To replace or clean check
valve" in the maintenance section).
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