TM 5-4310-362-14
Troubleshooting
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1. SLOW PUMPING OR INSUFFICIENT PRESSURE
Step 1. Check for leaks in air lines and fittings.
Tighten fittings or replace leaking parts.
Step 2. Check for overloading of the compressor.
Reduce air use to less than 5 cfm.
Step 3. Check for wrong adjustment of pressure switch.
Adjus t pressure switch to cut in at 160 psi and to cut out at 180 psi. (para 6-14)
Step 4. Check for bad head valves (para 8-12).
Repair or replace valves (para 8-13).
2. EXCESSIVE COMPRESSOR OIL CONSUMPTION
Step 1. If unit is new, oil consumption may be high until rings seat.
Wait for rings to seat, then recheck oil consumption.
Step 2. Check for worn or stuck piston rings.
Replace bad rings. (para 8-17)
NOTE
Rings can be replaced by removing head and cylinder.
The pump can stay
mounted on the air tank.
3. COMPRESSOR RUNS NOISY
Step 1. Check for loose mounting bolts or flywheel.
Tighten.
Step 2. Check for foreign matter such as carbon, metal chips, etc. in cylinder.
Remove head and clean cylinder. (para 8-11)
Step 3. Check if piston extends above cylinder at top of stroke and hits cylinder head.
Add gaskets between crankcase and cylinder. Do not add gaskets between cylin-
der and head since air leaks may occur if more than one gasket is used.
Step 4. Check for end play in crankshaft.
Remove one end cover gasket and reinstall end cover. Do not remove too many
gaskets or the crankshaft may bind. (para 8-17)
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