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Troubleshooting
3A1211M 7
Troubleshooting
NOTE: Check all possible problems and causes before
disassembling the pump.
Relieve the pressure before checking or servicing
the equipment.
Problem Cause Solution
Air motor will not run. Damaged air valve (17). Replace or service air valve (17).
See page 9.
Damaged pilot valve (19). Replace pilot valves (19). See page
11.
Air continuously exhausting
around air motor piston rod.
Damaged u-cups (3, 33). Replace piston rod u-cups (3, 33).
See page 12.
Air continuously exhausting from
muffler.
Damaged air valve plate (105) or cup
(112).
Replace or service air valve (17).
See page 9.
Damaged piston o-ring (8). Replace seals. See page 12.
Air motor “bounces” at top of
stroke.
Damaged bottom pilot valve. Replace bottom pilot valve (19). See
page 11.
Air motor “bounces” at bottom of
stroke.
Damaged top pilot valve. Replace top pilot valve (19). See
page 11.
Icing inside motor. Air motor operating at high pressure
or high cycle rate.
Reduce pressure, cycle rate, or duty
cycle of motor.
Reduce dew point of compressed
air in moisture coalescing filter.