Inspection Frequency; Adjust Needle Assembly; Service Valve Stem And Seal - Graco 249514 Operation And Parts Manual

Inspection Frequency

Dispense Gun
Inspect the dispense gun at every use for leakage or
other visible damage.
Heater
Every two weeks, check the heater for proper resis-
tance. Resistance should be approximately 890 ohms,
+/- 70 ohms for the 240V valves. Replace the heater
if necessary. See Electrical Schematic on page 12 for
test point.
Also inspect the heater when performing regular mainte-
nance procedures.
Sensor
Every two weeks, check the sensor resistance. Resis-
tance should be 108 ohms at 70° F (21° C). Replace the
sensor if necessary.
Also inspect the sensor when performing regular main-
tenance procedures.

Adjust Needle Assembly

The trigger travel and corresponding valve opening are
factory set. To adjust this setting, use the following pro-
cedure.
1. Follow the pressure relief procedure in your supply
system manual (see Related Manuals on page 2).
2. Disconnect from power source and wait for the unit
to cool.
3. Disconnect the gun from the hose.
311209W
4. Use a 11/32 in. wrench to loosen hex nut (4g).
5. Trigger the gun and use a 1/8 in. open-end wrench
on the flats of the needle to turn the needle (4a)
clockwise one turn as viewed from the handle end
of the gun.
6. Release the trigger; a slight free play of the trigger
handle should occur.
7. Repeat Step 4 until free play occurs.
8. Tighten hex nut (4g) to lock the adjustment.

Service Valve Stem and Seal

If fluid leaks past seal (4c), the seal or needle (4a) may
be worn or damaged. To replace the seal or valve stem,
use the following procedure:
1. Follow the Pressure Relief Procedure in your supply
system manual (see Related Manuals on page 2).
2. Disconnect from power source and wait for the unit
to cool.
3. Disconnect the gun from the hose.
4. Remove cover (16), and then slide the heater car-
tridge and sensor cartridge out of body (2).
5. Loosen the needle nut.
6. Remove screws (33).
7. Unscrew the needle with the body from the yoke.
8. Remove the seal-cartridge assembly from the body
and replace seals and/or needle. Repack the
grease area of the packing nut prior to reassembly.
9. Reassemble in reverse order and follow Adjust
Needle Assembly.
Service
13