Graco Inc. 965786 - Manual (Page 10)

10 308876
Troubleshooting
WARNING
To reduce the risk of serious injury
whenever you are instructed to relieve
pressure, always follow the Pressure
Relief Procedure on page 8.
SKIN INJECTION HAZARD
1. Relieve the pressure.
2. Check all possible causes to the problem before
disassembling the pump.
PROBLEM CAUSE SOLUTION
Valve does not open Insufficient air pressure Turn on or turn up air pressure.
Air not exhausted from behind air cylin-
der piston Use four-way, relieving-type air valve operator.
Shaft adjustment too far closed Adjust the shaft stroke as instructed on page 9.
Valve does not close
(leaks) Insufficient air pressure Turn on or turn up air pressure.
Air not exhausted from behind air cylin-
der piston Use four-way, relieving-type air valve operator.
Blockage between needle and seat Remove and clean needle and seat.
Bad or missing gasket between seat
and housing Replace gasket (38).
Needle worn out Replace needle and seat.
Higher than normal
back-pressure Nosepiece plugging up Remove and clean.