Graco Inc 307-308, 226-813, 1007 manual Service

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DecreasedDelivery

Accompanied By Smooth

Operation

Plugged or constricted suction piping (suction valve not fully open);

Collapsed suction hose.

Worn valve seats.

Slipping couplers.

Examine the water in the barrel or tank for air

bubbles whilethepumpis discharging. Ifno bubbles areseen and the discharge has actually decreased, look for plug-ups, worn valve seats, or collapsed suction hose. If bubbles areseen, look for air leaks in the suction piping or forair leaking past the piston cups. These leaks are hard to find because they are leaking "in" rather than "out".

However,ifarrangements are made to put pressure intothesuction piping orifnewcups smoothoutthepump operation, theproblemis

solved

Lookfor worn or pitted valveseats. Replace if necessary.

Measureclearancebetweenoutersurfaceor

eccentric roller bearingandyokepads with a feeler gauge. Thisshould not exceed 0.010 inch

(0.2% mm).

NOTE: Worn yokepads will give a verynoisy operation. Replace the yoke or pads if necessary.

Excessive Leakage	Worn piston cups;
	Loose piston bolts;
	Damaged O-rings;
	Cracked ceramic liners;
	Faulty gaskets;
	Loose valve caps;

Examine pistonsandcups for wear. Generally a cup will not leak severelyuntil it is torn.The piston should not be more than0.020in. 10.508 mm) out of round.

Tighten loose piston bolts, cylinder headbolts and valvecaps. Removeheadandsand flatparton 80-grit sandpaper which is laid on a flat surface.

CheckO-rings andgaskets for wear orbreaks.

Loose cylinder head bolts or malfitted heads.

SERVICE

Remove cylinder heads andblocks to examine ceramic liners for cracks. Replace all damaged parts.

Pistons and Yoke

Take off the cylinder head (14) by removing four112 in. socket head capscrews(A). See Fig 3.

Use a 7/32 in. socket wrenchto unscrew the piston bolt

(13)from the yoke. Slide out the cylinder liner (21) and piston assembly. Leave the yoke in place.

Examine the ceramiccylinder liner (21)forcrackstight. Replace worn or cracked parts before reassemblinginto pump body.

NOTE: Dirty grease sludgeadhering to thewallof thecylinder liner shouldberemoved with emery cloth before theliner is replacedin the pump body.

Assembleallpistonparts (10. 11. 12. 13,21, 22, 23, 24)		'	'
as shown and push theassembly into the. cylinder liner.
Make sure thatthe O-ring is in the recess of thepiston
cap.
Screwthepistonboltintothe	yoke. The bolt has a

countersunkheadcapscrewofthelockwelltypeand

will require a-little extra effort to turn. Makecertain it is to prevent leakage throughthe b.olt hole.

Repeat the procedurefor the oppositeside of the pump.

307-308 5