10
307–452
Troubleshooting
WARNING
To reduce the risk of serious injury whenever you
are instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 8.
1.
Relieve the pressure before you check or service
any system equipment.
2.
Check all possible causes and solutions in the
Troubleshooting Chart before disassembling the
gun.
NOTE: Some improper patterns are caused by the
improper balance between air and fluid.
Problem:
Improper Spray Pattern
Cause
Solution
Fluttering or spitting spray
Insufficient fluid supply.
Loose fluid nozzle or damaged fluid
nozzle taper seat.
Dirt between fluid nozzle, taper seat,
and body.
Loose or cracked fluid inlet fitting (22).
Loose fluid tube in cup or tank.
Dry or worn fluid needle packing or
loose packing nut permits air to get
into fluid passage (siphon feed).
Adjust fluid regulator or fill fluid supply.
Tighten fluid nozzle or replace fluid
nozzle and needle.
Clean.
Tighten or replace fitting.
Tighten.
Lubricate or replace packings (10);
tighten packing nut (9).
Fluid build-up on air cap; partially
clogged horn holes. Full air pressure
from clean horn hole forces fan pattern
toward clogged end.
Damaged fluid nozzle or air cap holes.
Clean with soft implement or sub-
merge in suitable solvent and wipe
clean.
Replace damaged part.
Fluid build-up on the perimeter of fluid
nozzle orifice, or partially clogged fluid
nozzle orifice.
Remove obstruction. Never use wire
or hard instruments.
Too high atomization air pressure.
Fluid too thin.
Not enough fluid pressure.
Reduce air pressure or adjust fan ad-
justment valve (5).
Regulate fluid viscosity.
Increase fluid pressure.
Low atomization air pressure.
Fluid too thick.
Too much fluid.
Increase air pressure or adjust air ad-
justment valve (17).
Regulate fluid viscosity.
On siphon feed guns, reduce fluid flow
by adjusting fluid adjustment knob (6).
On pressure feed guns, reduce fluid
pressure. Adjust fluid adjustment knob
(6) until proper pattern is obtained.
Streaks
Last coat of fluid applied too wet.
Too much air pressure.
Insufficient air pressure.
Non-uniform spray pattern.
Apply drier finish with multiple strokes.
Use lowest air pressure necessary.
Increase air pressure.
Clean or replace air cap.
