Troubleshooting - Graco Dyna-Star 26A938 Instructions Manual

Troubleshooting

Problem
Air motor will not run.
Air continuously exhausting around
air motor piston rod.
Air continuously exhausting muffler.
Air motor "bounces" at top of
stroke.
Air motor "bounces" at bottom of
stroke.
Icing inside the motor.
Manual 3A7718A
1. Relieve pressure before checking or servicing the
equipment, following the pressure relief procedure
for your system.
NOTE: Check all possible problems and causes before
disassembling the air motor.
Cause
Damaged air valve (17).
Damaged pilot valve (19).
Damaged u-cups (3, 33)
Damaged air valve plate (105) or
cup (112)
Damaged piston o-rings (8)
Damaged bottom pilot valve.
Damaged top pilot valve.
Air motor is operating at high
pressure or high cycle rate.
Troubleshooting
Solution
Replace or service air valve (17),
see page 18.
Replace pilot valves (19), see page
12.
Replace piston rod u-cups (3, 33),
see page 13.
Replace or service air valve (17),
see page 10.
Replace the seals, see page 13.
Replace bottom pilot valve (19),
see page 12.
Replace top pilot valve (19), see
page 12.
Reduce pressure, cycle rate, or
duty cycle of motor.
Reduce the dew point of
compressed air by using a moisture
coalescing filter.
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