Graco LineLazer GM 3500 Manuel D'instructions page 78

PROBLEM
Displacement pump output low on
downstroke or both strokes
Paint leaks into wet–cup
Spitting from gun
Troubleshooting
CAUSE
Pump inlet screen clogged
Pressure setting too low
Dirty outlet filter, tip filter or tip
Piston packings worn or damaged
Intake valve ball check not seating
properly
Engine RPM too low
Clutch worn or damaged
Partially clogged suction tube assembly
Large pressure drop in hose
Loose wet–cup
Throat packings worn or damaged
Displacement rod worn or damaged
Air in fluid pump or hose
Tip partially clogged
Fluid supply is low or empty
Dried paint particles from a poorly cleaned
suction tube assembly
SOLUTION
Clean screen.
Increase pressure. See Startup,
Step 14, page 13.
Clean filters and/or tips.
Replace packings. See page .
Clean and service intake valve. See 307–806.
Increase throttle setting. See Startup,
Steps 5b and 14, page 13.
Replace clutch. See page 32.
Remove and clean suction tube. During normal
flushing remove and clean the suction tube as-
sembly separately to prevent further clogging.
Use larger diameter hose.
Tighten wet–cup just enough to stop leakage.
Replace packings. See 307–806.
Replace displacement rod. See 307–806.
Check for loose connections at pump intake and
tighten. Them prime the pump.
See Startup, page 13.
Clear tip clog. See page 15.
Refill and prime the pump. See Startup, page 13.
Check fluid supply often to prevent running the
pump dry.
Remove and clean suction tube. During normal
flushing remove and clean the suction tube as-
sembly separately to prevent further clogging.