Troubleshooting
3Z9478A
35
Problem
Cause
Solution
Pump cycles but pressure does
not build up.
Pump not primed.
Prime pump, page 15.
Inlet screen clogged.
Clean debris off inlet screen
Suction tube not immersed.
Reposition suction tube in bottom of paint pail.
Paint pail empty.
Refill paint pail and reprime sprayer.
Suction tube has vacuum air leak.
Tighten suction tube connection. Inspect for cracks or
vacuum leaks. If cracked or damaged, replace.
Pump check valves are dirty or
damaged.
Return sprayer to Graco/M
AGNUM
authorized service
center.
Prime/Spray valve worn or
obstructed with debris.
Pump check ball stuck.
See “Pump will not prime” section of Troubleshooting
table, page 34.
Cannot pull gun trigger.
Gun trigger safety engaged.
Remove gun trigger safety
Gun stops spraying.
Spray tip clogged.
1 Turn arrow-shaped handle to unclog position.
2 Aim gun into waste pail.
3 Squeeze trigger.
4 Return arrow-shaped handle to spray position
and begin spraying.
Pump cycles but paint only
dribbles or spurts when trigger is
pulled.
Pressure is set too low.
Turn pressure control knob right to increase pressure.
Spray tip clogged.
Clean tip. See “Gun stops spraying” section of
Troubleshooting table, page 34.
Spray tip too large or worn.
Replace tip.
Gun filter clogged.
Clean or replace gun filter, page 48.
InstaClean fluid filter is clogged.
Clean or replace InstaClean fluid filter, page 47.
Pump check ball stuck.
See “Pump will not prime” section of Troubleshooting
table, page 34.
Pressure set at maximum, but
cannot achieve good spray
pattern.
Tip is too large for sprayer.
Select smaller tip, Tip Hole Size, page 30.
Tip is worn beyond capability of
sprayer.
Replace tip.
Gun filter clogged.
Clean or replace gun filter, page 48.
Inlet screen clogged.
Clean debris off inlet screen.
Pump valves worn.
Check for worn pump valves:
1 Prime sprayer with paint.
2 Trigger gun momentarily. When trigger is
released, pump should cycle and stop.
3 If pump continues to cycle, pump valves may be
worn.
4 Return sprayer to Graco/M
AGNUM
authorized
service center.
InstaClean fluid filter clogged.
Clean or replace InstaClean fluid filter, page 47.
Extension cord too long or not
heavy enough gauge.
Replace cord, Grounding and Electrical Requirements,
page 10.