Graco HVLP Series Instructions-Parts List Manual page 20

Spray Gun Problems
PROBLEM
No or slow fluid flow,
intermittent spray, or
fluttering spray
Fluid leaks at fluid nozzle
after the trigger is released
Poor spray pattern
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Troubleshooting
CAUSE
Wrong size fluid set being used or the
o–ring on nozzle is missing
Gun fluid nozzle blocked by dried
paint, or damaged
Cup or pressure pot cover not tight
enough, or gasket damaged
Cup or pressure pot fluid tube blocked
by dried paint or damaged
Air flow to cup blocked
Needle packings not properly adjusted
NOTE: Fluid loss though the packings
affects fluid pressure and causes a
fluid leak from the gun body.
Plugged inlet strainer
Needle not seating in fluid nozzle
Air cap horn holes and/or fluid nozzle
plugged
SOLUTION
Select the proper fluid set for the fluid
being sprayed (see page 8) or put an
o–ring on the nozzle.
Clean or replace fluid nozzle.
Tighten cover or replace gasket.
Clean or replace fluid tube.
To check, remove the cup (leave cover
connected), trigger the gun and check
for air flow out of the duckbill valve. If
air is not flowing freely, clean or
replace the duckbill valve.
Clean the gun body with solvent and
the brush provided. Adjust the needle
packings.
Replace strainer if plugged or remove
strainer if material is highly viscous.
Check for a loose fluid nozzle or a
bent nozzle or needle; tighten the
nozzle or replace parts as needed.
Soak air cap and/or fluid nozzle in
solvent. Clean air cap horn holes with
non-metallic item to avoid permanently
damaging them. See page 14.