Pump Troubleshooting - Graco Uni-Drum Instructions Manual

Pump Troubleshooting

For additional information about the displacement Pump, refer to Related Manuals on page 3 to find the applicable
instruction manual.
Problem
Rapid downstroke or upstroke
(pump cavitation)
Material leaks around Pump outlet
Material leaks around Bleed Port (Q) Bleed Port fitting is loose.
Pump won't move up or down
Wet cup leaks
309028ZAT
Cause
Air is trapped in Pump.
Downstroke: Lower check in Pump
is worn.
Upstroke: Upper check in Pump is
worn.
Outlet fitting is loose.
Problem with air motor.
Foreign object lodged in Pump.
Worn throat packings.
Troubleshooting
Solution
Bleed air from the Pump using this
procedure:
1. Place a waste container under
the Pump Bleed Port (Q).
2. Press the PRIME PUMP
Pushbutton to turn on air to the
Pump.
3. Allow material to flow from the
Bleed Port until it is air-free.
4. Release the PRIME PUMP
Pushbutton to shut off air to the
Pump. Close the Bleed Port.
5. Turn air on to the Pump and set
the Pump air regulator for normal
operation.
Rebuild and replace Pump, as
necessary.
Tighten outlet fitting.
Tighten Bleed Port fitting.
See Air Motor Troubleshooting
chart on page 54.
Remove object and rebuild Pump
assembly.
Tighten wet cup. Replace throat
packings.
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