Troubleshooting - Graco GX-8 Operation, Parts, Service, Repair

Troubleshooting

Troubleshooting
Follow Pressure Relief Procedure, page 17, before
checking or repairing gun.
To prevent cross-contamination of the equipment's wet-
ted parts, never interchange component A (isocyanate)
and component B (resin) parts. The gun is shipped with
the A side on the left. The gun block and the screen
screw are marked.
Problem
Gun does not fully actuate
Fluid does not pour when gun is fully
actuated
Gun actuates slowly
Gun delays, then actuates abruptly
Gun does not actuate
Pressure imbalance
Fluid does not shut off when fluid
valves are closed
Leak between air cylinder and fluid
housing
Material leaking out weep ports in fluid
housing near air cylinder
26
NOTICE
Cause
Safety lock engaged
Air not vented on open/close ports
Loss of air
Closed manual valves
Plugged orifice ports
Plugged check valves
Safety lock engaged
Loss of air pressure
Damaged piston o-rings
Cured material around the purge rod Inspect purge rod, mix module, and
Air supply to gun is shut off
Foam build-up around front tip
Plugged orifice ports
Plugged check valves
Plugged fluid screens
Damaged fluid valves
Damaged o-ring
Mix module and rear seal worn
Use the following table to check all possible problems
and causes before disassembling gun. See Mainte-
nance on page 18 for referenced procedures.
Solution
Disengage piston safety lock
Vent open air port when closing, vent
close air port when opening
Check air source
Open valves
Clean orifice ports
Clean check valves
Disengage piston safety lock
Check air source
Replace air piston o-rings
orifices. Replace if necessary
Open air supply
Clean off front tip.
Clean orifice ports
Clean check valves
Clean screens
Replace
Replace
Inspect and replace mix module and
rear seal, clean fluid housing
311338N