Troubleshooting - Graco 237-004 Instructions-Parts List Manual

WARNING
To reduce the risk of serious injury whenever you
are instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 8.
PROBLEM
Pump fails to operate
Pump operates but output
low on both strokes
Pump operates but output
low on down stroke
Pump operates but output
low on up stroke
Erratic or accelerated
operation
* To determine if the fluid hose or gun is obstructed, relieve the pressure. Disconnect the fluid hose and place a container at the
pump fluid outlet to catch any fluid. Turn on the air just enough to start the pump (about 20–40 psi [140–280 kPa, 1.4–2.8 bar]). If
the pump starts when the air is turned on, the obstruction is in the fluid hose or gun.
306–694

Troubleshooting

CAUSE
Restricted line or inadequate air supply
Obstructed fluid hose, gun, or
dispensing valve
Exhausted fluid supply
Fluid dried on displacement rod
Damaged air motor
Restricted line or inadequate air supply
Obstructed fluid hose, gun, or
dispensing valve
Exhausted fluid supply
Air in displacement pump and hose
Check valves need adjustment
Packing nut too tight or too loose
Worn throat packings
Held open or worn intake valve
Held open or worn fluid piston valve
or packings
Exhausted fluid supply
Packing nut too tight
Check valves need adjustment
Held open or worn intake valve
Held open or worn fluid piston valve
or packings
1. Relieve the pressure.
2. Check all possible causes and problems before
disassembling the pump.
SOLUTION
Clear; increase air supply.
Open, clear.*
Refill; purge all air from pump and fluid lines.
Clean; always stop pump at bottom of stroke;
keep wet–cup 1/2 filled with compatible solvent.
Service air motor (see 307–049 or 307–304).
Clear; increase air supply.
Open, clear.*
Refill; purge all air from pump and fluid lines.
Reprime.
Adjust (see manual 307–862).
Adjust (see page 11).
Replace (see manual 307–862).
Clear; service. See manual 307–862.
Clear; service. See manual 307–862.
Refill; purge all air from pump and fluid lines.
Adjust (see page 11).
Adjust (see manual 307–862).
Clear; service. See manual 307–862.
Clear; service. See manual 307–862.