3M Scotch-Weld Owner's Manual - Troubleshooting
© 3M 2006
8
Troubleshooting
Problem
Probable Cause
Correction
(In order of priority)
Low or no adhesive flow
1. Hung adhesive stick
Turn on the 3M™ Scotch-Weld™ Hot Melt
Applicator PG II and allow it to heat for at
least 60 minutes. With incoming air at 80 psi
extrude adhesive. If unsuccessful remove
nozzle assembly and extrude one stick of
adhesive. Readjust incoming air to 80 psi.
Check to see if there is sufficient air
pressure. Test by setting pressure at 80 psi.
Check in-line filter to insure that it is not
plugged with contaminants. Disconnect in-
line filter from air hose. Using a
compressed air line, blow compressed air
through the filter in the reverse flow
position. If this does not increase air flow
through the filter, swivel filter should be
replaced.
Check to see that electrical service is live,
and that lighted switch is in “on” position.
Remove nozzle valve and clean. Run one
adhesive stick out. Replace cleaned valve
assembly.
Squeeze trigger and try to pull retract
knobs. If they can be pulled back easily,
install new regulator kit.
With Volt/Ohm Meter, run electrical
continuity check on each heater (see page
13 for procedure). If open circuit exists,
install new heater kit.
If the piston is retracted before reaching the
point where the whistle is heard, a jam-up
of the adhesive may occur. To free this,
simply retract the piston fully and roll the
applicator to one side so that the adhesive
in the magazine will free itself. Now push
the knobs forward until the adhesive stick
still in the chamber is contacted by the
piston. Roll the applicator back to its
normal operating position and continue
extruding adhesive until the whistle is heard
or until the piston has traveled its full length
as indicated by the orange retract knobs.
Replace with new Thermostat/TCO kit.
Refer to page 14, paragraph J.
With finger off of trigger, attempt to retract
piston. If piston is very difficult to pull back,
air regulator may not be shutting off
entirely. Replace regulator.
Extrude one adhesive stick.
Replace with new nozzle valve assembly.
Refer to page 12, paragraph C.
2. Low air pressure
3. No electricity
4. Dirty nozzle valve assembly
5. Regulator malfunction
6. Burned out heater(s)
7. Jammed slugs
1. Blown thermal cutoff
1. Regulator malfunction
2. Expanded adhesive stick
3. Worn nozzle valve
No heat
Dripping Nozzle