10
H5-991-406A
W0202
2. Remove and Inspect Valve
Assemblies (3, 11-17, 44-47)
Note: Wanner Repair Kits contain some or all of the required
components to replace items (3), (11-17), and (44-47), as well
as all O-rings for sealing the manifold to the valve plate.
Consult the appropriate Parts Manual for your pump to
determine which Repair Kit to order.
Remove.the.Valve.Assemblies
The.three.inlet.and.three.outlet.valve.assemblies.in.the.pump.
are.identical.(but.face.in.opposite.directions)..One.at.a.time,.
remove.each.valve.assembly.,.then.inspect.and.reinstall.the.
valve.assembly.as.outlined.below..Be.careful.not.to.bend.or.
break.any.of.the.metal.valve.components,.and.not.to.gouge.or.
scrape.the.plastic.valve.plate.
Set.the.valve.plate.on.-in..high.blocks,.with.the.valve.assemblies.
facing.down..As.you.press.out.each.valve.assembly.during.the.
following.procedure,.be.sure.there.is.enough.open.space.below.
so.that.the.valve.can.come.out.of.its.bore.unobstructed.
To remove each valve assembly:
H/G-25-SD Service (Fluid End)
Service Procedure
1. Remove Manifold Support
(43), Manifold (7), and Valve
Plate (18)
a...With.an.8-mm.(or.5/16-in.).hex.Allen.wrench,.and.a.16-mm.
box-end. wrench,. remove. all. nuts.(31). and. capscrews. (5).
around.the.manifold.support.plate..Do.not.remove.the.four.
capscrews.(6).that.are.installed.through.the.back.of.the.
pump.housing.
b...With. a. 10-mm. hex. Allen. wrench,. remove. the. centerbolt.
(1).and.its.washer.().in.the.center.of.the.manifold.support.
plate.
.
Caution: Do not turn the pump drive shaft while the
manifold and valve plate are off the pump, except
when removing diaphragms or repriming the hydraulic
cells.
c... Remove.the.manifold.support.(43).and.manifold.(7).
d...Inspect.the.manifold.support.and.manifold.for.warpage.or.
wear. around. the. inlet. and. outlet. ports.. Also. inspect. the.
manifold.for.warpage.or.wear.in.the.area.of.the.flow.channels,.
especially.where.the.valve.assemblies.contact.the.manifold..
If.wear.is.excessive,.replace.the.manifold.with.a.new.one.
.
To.check.the.manifold.support.for.warpage,.lay.it.on.a.flat.
surface.and.place.a.straightedge.across.it..Check.both.sides.
of.the.plate.for.warpage.
.
To.check.the.manifold.for.warpage,.first.be.sure.any.plugs.
or.O-rings.are.removed,.then.lay.it.on.a.flat.surface.with.the.
flow.channels.facing.you..Place.a.straightedge.across.the.
raised.surfaces.of.the.manifold.
.
Note: A machined recess was cut around the perimeter
of the manifold at the factory. Do not mistake this feature
for warpage.
.
A. warped. manifold. support. or. manifold. should. be.
replaced.
e...With.a.5-mm.hex.Allen.wrench,.remove.the.three.socket-
head.capscrews.(39).that.hold.the.valve.plate.to.the.cylinder.
casting.
.
Note: There is an O-ring (48) under the head of each
capscrew, which acts as a washer between it and the
plastic valve plate.
