4. Remove spool plug and carefully remove spool
assembly.
5. Remove the damper piston from the spool. The
piston will come out slowly, because of a partial
vacuum formed as it is removed. Use extreme care
to avoid damaging the polished surfaces of the pis-
ton or spool.
6. Remove the check valve spring retainer, spring
and check valve poppet. Check spring free length.
Replace spring if less than 1-1/2 inches (38.1 mm)
long.
CLEAN AND INSPECT
1. Discard all O-rings and backup rings. Clean all
parts in solvent and blow dry. Inspect polished sur-
faces of spool and damper piston for damage that
may cause binding or leakage. Inspect spool bore
in valve housing for damage or scoring. Inspect
check valve seat in valve housing and check valve
poppet. If the spools, bores or valves are damaged,
the entire valve must be replaced as these parts
are not serviced separately.
2. Inspect the .020-inch orifice in the end of the spool
and the pilot orifice to be certain they are open.
ASSEMBLY
1. Install new O-rings on the plug and spring retainers.
2. Install new O-rings and backup rings on the spool
and damper piston as shown. It is important that
each backup ring is on the correct side of its O-ring.
Take care not to cut the O-rings during assembly.
Let the spool and damper piston set for ten minutes
before installing them in their respective bores. This
will allow the O-rings to return to their original size
after being stretched.
3. Lubricate the spool and damper piston O-rings with
hydraulic oil. Carefully install the damper piston into
the spool.
4. Lubricate the spool bore and spool O-rings with
hydraulic oil. Carefully install the spool into the
valve housing. Always install the spool from the
plug end as shown to minimize the possibility of
damaging the O-ring. Install the plug, spool spring
and spring retainer.
5. Install the check valve poppet, spring and check
valve spring retainer.
6. Install the motor drain check ball, spring and elbow
fitting.
7. Install the pilot orifice into the valve housing.
8. The brake valve is complete and ready to be
installed on the winch motor.
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