Graco Inc 800-668, 800-666 manual Pump Service, Valves, Pumping Section, Servicing the Plungers

PUMP SERVICE

WARNING

To reducetherisk ofserious bodily injury, including fluid injection, splashingin the eyes or on the skin, or injury from moving parts, always follow the Pressure Relief Procedure Warning

-before proceeding.

NOTE The following metric wrenches are needed: M10, M13 andM30. Repair kits are available. Refer to the individual repair sectionsand the pump partspagefor moredetails. For the best results, use all partsin the kits.

NOTE Thereare two different tool kits to aidin servicing the pump. P/N 800-298is used to easeinstallation of packings.P/N 800-271 includes the itemsin800-298andtools to aid in the removal ofpacking retainers.

Valves

NOTE: For a set of six valves, order P/N 801-472.

1.Removethehex plug fromthe manifold using an M30 wrench.

2.Examinethe O-ring under the hexplug and replace it if it is cut or distorted.

3.Removethevalveassemblyfromthecavity;the assembly may comeapart.

4.Install thenewvalve.Install theO-ring and hexplug; torque to 75 It-lb(103 Nm).

NOTE: Retorque the plug after 5 hours of operation.

Pumping Section

1.Remove the eight capscrews and lockwashers from the manifold using an M13 wrench.

2.Carefully separate themanifoldfrom the crankcase.

NOTE It may be necessaryto tap themanifoldlightly with asoft mallet to loosen.

CAUTION

Keepthe manifold properly aligned withthe

ceramicplungers whenremoving to avoid damage to the plunger or seals.

Servicing the Plungers

NOTE Plunaer reDairkit. P/N. 801-474 is availableto

I.

replaceretainers, O-rings, washers and backup rings for three cylinders.

1, Loosenthe plunger retaining screwfive to six turns, using an MlOwrench. Push theplungertowardsthe crankcase to separatetheplunger and retaining screw.

2.Remove the screw from the plunger and examine the O-ring,backup ring and copperbearinggasket washer. Replace these parts,ifnecessary,usingkit 801-474.

3.Remove the plunger and flinger from the plunger

shaftClean,examine.	and replacepartsas
necessary.

4.Inspect the plunger shaft for oil leakage from the crankcase. Ifleaking is obvious, replace the oil seals. Otherwise,DO NOT remove these seals as they cannotbe reused. An oil seal kit isavailableto replace the seals.

5.Lightly greasethe flinger andoil seal, if it is being replaced and replace them on the plunger shaft. Then install the plunger.

6.Lightly grease the retaining screw andoutertheend of the plunger. Place the washer, andO-ringbackup

ring around the screw and install the screw through the plunger.Torque to 14.4 ft-lb (19.5 Nm).

NOTE If you plan to replace the packings, refer to Servicingthe V-Packings.

7.Lubricate the outside of eachplunger.Slidethe manifold onto the crankcase, being careful not to damage the seals.

8. Installthecapscrewsand washersfinger-tight. Torquethe screwsto 21.7 ft-lb (29Nm) followingthe

tighteningpattern (Figure4).Uneven tightening may cause themanifoldto bind or jam.

II

3.Carefully examine each plunger for any scoring or cracking and replace as necessary.

Flgure 4

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