PUMP REPAIR SECTION
PISTON
REPLACEMENT
1. Remove the four hex head cap screws holding the
discharge manifold. Pull the discharge manifold off
with a slight rocking motion as shown in Picture 1,
then pull out the cylinders. Use a pair of pliers as
shown in Picture 2 and unscrew the piston retainer.
Remove the intake valve seat and piston assembly.
Use a wire brush to clean all sealant off the
threaded ends of the retainers and wipe the threads
clean with a rag soaked in alcohol or decreasing
solvent.
2. Place the piston assembly and the intake valve seat
on the retainer. The rubber cup side of the piston
is placed adjacent to the "+" portion of the
retainer and the rounded or smooth side of the
intake valve seat adjacent to the metal side of the
piston. Put one or two small drops of
adhesive/sealant onto the end of the male thread
on the retainer. Install the retainer in the pushrod
and tongue to 40-50 inch-pounds. DO not "fill"
the female threaded port ion of the push rod
or you will not be able to disassemble the
parts at some future time.
3. Check the inside surface of the cylinder before
replacing it; if it is badly scratched or scored,
replace it. Put a light film of oil on the inside
diameter of the cylinder and on the O-rings at each
end. Slip the cylinder over the piston as shown in
Picture 3 until it touches the intake manifold bore.
Push the cylinder into the intake manifold bore as
shown in Picture 4 until it is firmly seated. Take
care not to pinch the O-ring when replacing the
cylinder.
Tools referenced are not required
to disassemble, repair, or assemble
the water pump.
They are available
for major repair shops when volume
warrants.
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