Graco Pro 270GS, Operation

Troubleshooting

3A2818A

23

Problem

Cause

Solution

Pump does not prime.

Prime/Spray Valve is in SPRAY posi-
tion.

Turn Prime/Spray Valve to PRIME 
position (pointing down).

Inlet screen is clogged or suction 
tube is not immersed.

Clean debris off inlet screen and 
make sure suction tube is immersed 
in fluid.

Pump was not primed with flushing 
fluid.

Remove suction tube from paint. 
Prime pump with water or 
solvent-based flushing fluid, page 10.

Inlet valve check ball is stuck.

Remove suction tube and place a 
pencil into the inlet section to dis-
lodge the ball, allowing pump to 
prime properly.

Inlet valve check ball or seat is dirty

Remove inlet fitting. Clean or replace 
ball and seat. 

Outlet valve check ball is stuck.

Take sprayer to Graco authorized 
service center.

Suction tube is leaking.

Tighten suction tube connection. 
Inspect for cracks or vacuum leaks.

Pump does not prime with fluid.

Remove suction tube from paint. 
Prime pump with water or sol-
vent-based flushing fluid.

Fluids are viscous or sticky.

Thin paint per manufacturers guide-
lines.

Engine speed is too high

Decrease throttle setting before prim-
ing

Pump cycles but does not build up 
pressure.

Pump is not primed.

Prime pump.

Inlet screen is clogged .

Clean debris off inlet screen and 
make sure suction tube is immersed 
in fluid.

Suction tube is not immersed in paint. Make sure suction tube is immersed 

in paint.

Suction tube is leaking, allowing air to 
enter.

Tighten suction tube connection. 
Inspect for cracks or vacuum leaks. If 
cracked or damaged, replace suction 
tube.

Prime/Spray Valve is worn or 
obstructed with debris.

Take sprayer to Graco authorized 
service center.

Pump check ball is stuck.

Read 

Pump does not prime

 section 

in Troubleshooting, page 23.