Graco 308738C manual Troubleshooting, Problem, Cause, Solution

Troubleshooting

WARNING

To reduce the risk of serious injury whenever you are instructed to relieve pressure, always follow the Pressure Relief Procedure on page 8.

1.Relieve the pressure.

2.Check all possible problems and solutions before disassembling pump.

Problem	Cause	Solution
Pump fails to operate.	Restricted line or inadequate air	Clear; increase air supply.
	supply.
	Insufficient air pressure; closed or	Open; clean (be sure to use air fil-
	clogged air valves, etc.	ter).
	Exhausted fluid supply.	Refill; purge all air from pump and
		fluid lines.
	Damaged air motor.	Service air motor. See manual
		306982.
	Fluid intake or piston valve needs	Adjust. See manual 307044.
	adjustment.
Pump operates but output is low on	Restricted line or inadequate air	Clear; increase air supply.
both strokes.	supply.
	Insufficient air pressure; closed or	Open; clean (be sure to use air
	clogged air valves, etc.	filter).
	Exhausted fluid supply.	Refill; purge all air from pump and
		fluid lines.
	Clogged fluid line, valves, etc.	Clear*.
	Loose packing nut or worn throat	Tighten packing nut (see page 8);
	packings.	replace throat packings.
	Damaged riser tube o-rings.	Replace. See manual 307044.
Pump operates but output is low on	Held open or worn intake valve.	Clear; service. See manual 307044.
downstroke.
	Damaged riser tube o-rings.	Replace. See manual 307044.
Pump operates but output is low on	Held open or worn fluid piston valve	Clear; service. See manual 307044.
upstroke.	or packings.
Erratic or accelerated operation.	Exhausted fluid supply.	Refill; purge all air from pump and
		fluid lines.
	Held open or worn intake valve.	Clear; service. See manual 307044.
	Held open or worn fluid piston valve	Clear; service. See manual 307044.
	or packings.
	Damaged riser tube o-rings.	Replace. See manual 307044.

*To determine if the fluid hose or gun is obstructed, relieve the pressure and 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 1.4 to 2.8 bar (0.14 to 0.28 MPa, 20 to 40 psi). If the pump starts when the air is turned on, the obstruction is in the fluid hose or gun.

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