Graco GM 3500 - Page 14

14
307-863
Troubleshooting
PROBLEM CAUSE SOLUTION
Displacement pump output
low on upstroke
Pump inlet screen clogged Clean.
Piston ball check not seating Service piston ball check. See page 18.
Piston packings worn or damaged Replace packings. See page 18.
Sleeve gasket in displacement
pump worn or damaged
Replace. See page 18.
Displacement pump output
low on downstroke or both
strokes
Pump inlet screen clogged Clean.
Piston packings worn or damaged Replace packings. See page 18.
Intake valve ball check not seating
properly
Clean and service. See page 18.
Engine RPM too low Increase throttle setting. See Startup,
Step 1 1, page 10.
Clutch worn or damaged Replace. See page 24.
Paint leaks into wet–cup Loose wet–cup T ighten just enough to stop leakage.
Throat packings worn or damaged Replace packings. See page 18.
Displacement rod worn or
damaged
Replace rod. See page 18.
Low fluid delivery Pump inlet screen clogged. Clean.
Pressure setting too low Increase pressure. See Startup,
Step 1 1, page 10.
Engine RPM too low Increase throttle setting. See Startup,
Step 1 1, page 10.
Dirty outlet filter , tip filter or tip Clean.
Large pressure drop in hose Use larger diameter hose.
Spitting from gun Air in fluid pump or hose Check for loose connections at pump in -
take and tighten. Them prime the pump.
See Startup , page 10.
T ip partially clogged Clear.
Fluid supply is low or empty Refill and prime the pump. See Startup,
page 10. Check fluid supply often to pre -
vent running the pump dry .