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MODELS 2WN150L, 2WN150H
1.
Remove unloader piping from unloader towers
and unloader controls..
2. Suction
valves:
a. Remove the unloader assembly. Remove and
discard unloader gaskets.
b. Remove valve cover. Discard valve cover O-
ring.
c. Remove the unloader tube and valve assembly
and discard valve seat gasket.
d. Disassemble the valve and inspect the valve
seat, plate, spring, guide and unloader
fi
nger/
spring for wear. Repair or replace as necessary.
Valve seats can be lapped to clean up minor
damage. Valve plates should be replaced if
damaged. Turning over a damaged valve plate
will lead to premature failure of the plate and
possible damage downstream from debris.
Valve and unloader spring and valve guide
should be replaced if in doubt.
e. Reassemble the valve in the reverse order it
was disassembled. Check for free movement
of the valve plate. Tighten valve nut to speci
fi
ed
torque.
f. Reinstall a new valve seat gasket into the valve
pocket. Install valve assembly, verifying correct
valve orientation. The inlet valve plate should
move down when pushed from above with a
probe.
3. Discharge
valves:
a. Remove the valve cover and discard valve cover
O-ring. Remove the valve assembly.
b. Disassemble the valve and inspect the valve
seat, plate, and spring. Repair or replace as
necessary. Valve seats can be lapped to clean
up minor damage. Valve plates should be
replaced if damaged. Turning over a damaged
valve plate will lead to premature failure of the
plate and possible damage downstream from
debris. Valve springs should be replaced if in
doubt.
c. Reassemble the valve in the reverse order it
was disassembled. Check for free movement
of the valve plate. Tighten valve nut to speci
fi
ed
torque.
d. Reinstall a new valve seat gasket into the valve
pocket. Install valve assembly, verifying correct
valve orientation. The discharge valve plate
should NOT move when pushed from above
with a probe.
4.
Install valve cover with new valve cover O -
ring. Torque cap screws to proper tightness.
5.
Install the unloader tower and gasket on suction
valve covers. Torque to
fi
nal tightness.
6. Rotate
the
fl
ywheel by hand to insure there is
no interference between the valves and pistons. Also
listen for air moving across the valves.
7.
Reinstall unloader tubing.