Graco Inc 800-702 Pump Service, Servicing the Valves, Servicing the Pumping Section, 18308-531

PUMP SERVICE

Servicing the Valves

1.Remove the hex valve plug.

2.Examine the O-ring under the plug for cuts or distortion and replaceif wom. Lubricate new O-ring before installing.

3.Grasp valve retainerbytab at the top withpliers and remove from valve chamber. Valve parts usually separate during removal.

Note: A special tool will be neededto remove the seat from the manifold.A reverse pliers ora standard vise grip and1/4”a x 3”boltto fit I.D. of seat Inserted under the edgeofthe seat,will pry the valve seat out easily.

4.Examine all valve parts for wear and replace with preassembled valve assembly in sefvice kit containing retainer, spring, valve, valve seat, O-ring, and back-up ring.

5.Grasp new valve assembly by attabtop with pliers, immerse in oiland push into valve chamber. Be certain valve assembly is square in valve chamber.

6.ApplyLoctite242tovakreplug,threadintomanifold port and torque perchart.

Note: Corrosion Resistant models require thecoil spring installed in theValve Plug.

Servicing the Pumping Section

Dlsassembly:

1.Remove the four(4)hexnuts ortwo(2)boltsfromthe manifold (varies with model).

Reassembly:

1.Carefully examine each ceramic plunger for scoring or cracks, replaceifwomandslip onto plunger rod.

Note: Ceramic plunger can only be installedone direction (frontto back). Donot force onto rod.

2.Examine plunger retainer and stud and replaceif worn.

Note: Thread stud into plunger retainer.

3.Examine O-ring. back-up ring and gasket on plunger retainer and replaceifwomor cut. Lubricate O-ring for ease of installation and to avoid damaging O-rings.

Note: First install gasket, then back-up ring and O-ring.

4.Thread plunger retainer and stud assembly into plunger rod. Exercise caution notto over torque.

5.Saturate new oil wick by soaking in oil, place in seal retainer andslip retainer over ceramic plunger.

6.Replace oil pan.

7.Tum shaft by hand to line up plungers so end plungers are parallel.

8.Carefully slip manifold onto plungers, keeping manifold level, and tap with malletto bring manifold flush with crankcase.

9.Replace washers and nutsor bolts and torque per chart.

2.Rotate crankshaft by handto start separation of manifold from crankcase. Support the underside of the manifold and tap lightly with a malletto remove the manifold assembly.

CAUTION

Keep manifold properly aligned with ceramic plungers when removingto avoid damageto either plungers or seals.

3.Remove oil pan and slideout seal retainer with wicks.

4.Using a wrench, loosen the plunger retainer. Grasp ceramic plunger and push toward crankcase until plunger retainer pops out.

5.Remove plunger retainer with copper gasket, back-up Ring andO-ring.

6.Remove plunger from plunger rod.

Servicing the Seals and V-Packings

Disassembly:

1.Remove the manifold as described.

2.With crankcase side of manifold facing up, unscrew the seal case from the manifold usinga special key wrench.

3.Remove O-ring from seal case.

4.Remove snap ring and low pressure seal from the seal case. Seals are generally removed easily without anytools.

5.Hlgh Pressure Seal Models: The high pressure seal is generally easily removed from the manifold without anytools. Ifextremely worna reversepliers may be used.

6.V-PacklngModels: The female adapter, two v-packlngs and male adapter are easily removed from manifold without tools. If extremely wom a reverse pliers maybe used.

18308-531