37
BRAKE VALVE SERVICE
4.
Remove spool plug (Item 4) and carefully remove
spool (5).
5.
Remove the check valve spring retainer (2), spring
(10), and check valve poppet (8). 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 surfaces of
spool 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 because
these parts are not serviced separately.
2.
Inspect the .020-inch orifice in the pilot orifice (9) to be
certain it is open.
ASSEMBLY
1. Install new O-rings on the plug and spring retainers.
2. Install new O-rings and backup rings on the spool. It
is important that the backup ring is on the correct side
of its O-ring. Take care not to cut the O-ring during
assembly. Let the spool set for 10 minutes before in-
stalling them in their respective bores. This will allow
the O-ring to return to their original size after being
stretched.
3. Lubricate the spool bore and spool O-rings with hy-
draulic 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.
4. Install the check valve poppet, spring and check valve
spring retainer.
5. Install the solid plug into the drain port.
6.
Install the pilot orifice into the valve housing.
7. The brake valve is complete and ready to be installed
on winch motor.
