Graco 231-560 Instructions-Parts List Manual page 20

PROBLEM
The pump output is low on
the upstroke. the upstroke
The output of the pump is
low on the downstroke or on low on the downstroke or on
both of the strokes.
The paint leaks into the wet-
cup.
The fluid delivery is low.
Fluid is spitting from the gun.
The pump is difficult to prime.
CAUSE
The inlet screen (102) is clogged.
A piston ball (121) is not seating.
The piston packings are worn or damaged.
A o-ring (119) in the displacement pump is
worn or damaged.
The inlet screen (39) is clogged.
The piston packings are worn or damaged.
An intake valve ball is not seating
properly.
The engine speed is too low.
The clutch is worn or damaged.
The wetcup is loose.
The throat packings is worn or damaged.
A displacement rod is worn or damaged.
The inlet screen (39) is clogged.
The pressure setting is too low.
The engine speed is too low.
The fluid filter (21), the tip filter or the tip is
clogged or dirty.
There is a large pressure drop in the hose.
There is air in the pump or the hose.
The tip is partially clogged.
The fluid supply is low or empty.
There is air in the pump or the hose.
The intake valve is leaking.
The pump packings are worn.
The paint is too thick.
The engine speed is too high.
SOLUTION
Clean the screen.
Service the piston ball–check. See page 35.
Replace the packings. See page 35.
Replace the o-ring. See page 35.
Clean the screen.
Replace the packings. See page 35.
Clean the intake valve. See page 35.
Increase the throttle setting. See Step 16, page
10.
Replace the clutch. See page 28.
Tighten the wetcup just enough to stop leak-
age.
Replace the packings. See page 35.
Replace the rod. See page 35.
Clean the screen.
Increase the pressure. See Step 16, page 10.
Increase the throttle setting. See Step 16, page
10.
Clean the filter. See page 18. Or, see the gun
instruction manual.
Use a larger diameter hose.
Check and tighten all the fluid connections.
Reprime the pump. See page 10.
Clear the tip. See the gun instruction manual.
Refill the fluid supply. Prime the pump. See
page 9. Check the fluid supply often to pre-
vent running the pump dry.
Check and tighten all the fluid connections.
Reduce the engine speed and cycle the pump
as slowly as possible during priming.
Clean the intake valve. Be sure ball seat is not
nicked or worn and that the ball seats well.
Reassemble the valve.
Replace the pump packings. See page 35.
Thin the paint according to the supplier's
recommendations.
Decrease the throttle setting before priming the
pump. See Step 16, page 10.