Troubleshooting - Graco PR70 Repair And Parts Manual

Troubleshooting

Troubleshooting
Before starting any troubleshooting procedures, perform
the following procedure.
1. Relieve pressure. See Pressure Relief Procedure,
page 14.
2. Disconnect AC power from the machine.
Problem
Display Module completely dark
No or incorrect amount of material
dispensed from either side.
Piston stalled
Significant material leaking from
pump rear seal
16
3. Allow the machine to cool if the machine has a heat
Try the recommended solutions in the order given for
each problem to avoid unnecessary repairs. Verify all
circuit breakers, switches, and controls are properly set
and wiring is correct.
Cause
No power
Fuse blown
Loose connection
Bad display module
Ball valve closed (if installed)
Tank empty
Tank clogged
Air in material
Check valve malfunction
Piston worn or broken
Input air reduced or removed
Mixer blocked
Open Dispense Valve (ODV) adjust-
ment too late
Blocked check valve
Air cylinder failure
Pump shaft worn
control option.
Verify rear AC Power switch is ON.
Replace machine fuses.
Tighten 5-pin cable on Display Mod-
ule.
Replace Display Module.
Open tank ball valve.
Fill tank with material.
Verify no obstruction in the tank.
Prime the machine until the air is
removed.
Remove; clean or replace check
valve.
Remove and replace piston if worn.
Reconnect input air line to machine.
Increase air pressure regulator
adjustment.
Replace static mixer.
Incorporate purge timer or decrease
purge timer delay to prevent mixer
blockage.
Readjust the ODV setting to occur
sooner.
Remove check valve; clean and
replace.
Remove air cylinder and reinstall air
cylinder parts as necessary.
Remove pump shaft assembly, and
reinstall rear pump rebuilt kit.
Solution
312760Y