Air Leaks, Check Chart | Graco Inc 220106, 307741, 237000, 235525

Troubleshooting

Air Leaks

Air leaks are caused by worn or damaged gaskets or seals. To locate the leaks, first shut off the air supply to the pump and open the bleed-type master air valve to relieve air pressure. Disconnect the main air supply line from the air inlet. Remove the shield (27) as explained on page 10, then reinstall the other parts and connect the main air line to the inlet.

Open the bleed-type master air valve and adjust the air pressure to .07–0.1 MPa, 0.7–1.0 bar (10–15 psi). Stall the pump on both the up and down stroke as indicated in the Check Chart below. Use the methods listed in the Check Chart to find where air is leaking. See Fig. 2.

WARNING

MOVING PARTS HAZARD

Keep you fingers away from all moving parts while performing this test, to

reduce the risk of pinching or amputating your fingers. Reinstall the air motor shield before resuming normal operation of the pump.

Check for air leaks by feeling, listening, or squirting oil around the suspected area. The oil will bubble if there is a leak.

CHECK CHART

Stroke Position

Letter Ref. Points

Check Method

Cause of Leakage

UP stroke only

By listening for air leak at exhaust outlets

Worn trip rod packing (65).

	B	By feel	Blown air cylinder gasket
			(35).

	C	Squirt oil around wiper (44)	Worn throat packing (46).

	G	By feel	Damaged cylinder gasket
			(38).

DOWN stroke only	D	By feel.	Damaged air manifold gas-
			ket (30).

BOTH strokes	E	By feeling exhaust, or	Worn director valve (3).
		hearing a high-pitched	Replace, or lap faces with
		sound	no. 500 grit sandpaper.

	F	By feel, or hearing a high-	Worn piston o-ring (33).
		pitched sound

	D or G	By feel	Blown manifold gaskets
			(38 and 30).

	H	Squirt oil around o-ring	Damaged housing o-ring
		(15)	(15).

	K	By feel	Damaged o-ring (26).

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