Graco 236752 Heat Pump User Manual


 
Troubleshooting
10 308391J
Troubleshooting
1. Follow Pressure Relief Procedure, page 8, before
checking or repairing gun.
2. Check all possible problems and causes before dis-
assembling gun.
Problem Cause Solution
Pump will not run
Closed dispense valve Pump only runs with valve open.
Pressure too low
Increase supply pressure using the
pressure adjusting valve.
Insufficient hydraulic fluid supply
Check hydraulic power supply.
Adjust to a maximum of 12 gpm
(45.4 lpm) flow
Clogged fluid outlet line, intake
valve, dispense valve, suction line
Check; clear obstructions.
Motor stalled
Press reciprocator reset button (39).
Pump should start immediately. See
Parts Drawing on page 16.
Reciprocator damaged Repair. See pages 11 through 15.
Pump speeds up or runs erratically
Pump piston and/or intake valve
worn
Check and repair. See Page 11
Empty supply container
Refill and reprime. Do not allow
pump to run dry. Monitor closely or
use a low-level cutoff valve.
Pump runs, but output low on up
and/or down strokes
Pump piston and/or intake valve
worn
Check and repair. See Page 11.
Insufficient material fluid supply Refill fluid supply container.
Pressure too low
Increase supply pressure using the
pressure adjustment on the control.
Clogged fluid outlet line, intake
valve, dispense valve, suction line
Check; clear obstructions.
Excessive weepage from porous
plug (B)
Worn throat seals Repair. See page 11
Hydraulic oil leaks from seal nuts in
the upper housing or cap (36, 43)
Seal nuts (19) are loose, worn, or
damaged
Tighten the seal nuts. If leaking per-
sists, change the seal nuts.
Pump runs slowly with dispense
valve closed
Pump/dispense line leakage
If system is OK, rebuild the pump.
Use kits 220457 and 236862.