Graco D Series Operation, Parts page 29

Problem
Sprayer runs, but pump does not
prime or looses prime while in use.
(Pump cycles but does not pump
paint or build pressure.)
3A3234E
Cause
Inlet valve check ball is stuck.
Prime/Spray Valve is in SPRAY
position.
Pump was not primed with flushing
fluid.
(Thick fluids may not prime if not
initially primed with flushing fluid.)
Debris in paint.
Thick or "sticky" paint.
Inlet strainer is clogged or suction
tube is not immersed in paint.
Inlet valve check ball or seat is dirty.
Suction tube is leaking.
Outlet valve check ball is stuck.
Prime/Spray Valve is worn or
obstructed with debris.
Troubleshooting
Solution
Press PushPrime button to dislodge
the ball allowing pump to prime
properly.
Turn Prime/Spray Valve down to
PRIME position until paint exits drain
tube. The pump is now primed.
Remove suction tube from paint.
Prime pump with oil or water-based
flushing fluid. See page 13.
Strain the paint. See page 11.
Some fluids may prime faster if the
ON/OFF switch is momentarily turned
off so the pump can slow and stop.
Turn ON/OFF switch on and off
several times if necessary.
Clean debris off inlet strainer and
make sure suction tube is immersed
in paint.
Remove inlet fitting. Clean or replace
ball and seat. See page 26.
Inspect suction tube connection for
cracks or vacuum leaks.
Unscrew outlet valve, remove, and
clean assembly.
Take sprayer to an authorized service
center.
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