BRADEN CH SERIES Installation Maintenance And Service Manual page 40

CLEAN AND INSPECT
1. Discard all O-rings and back-up rings. Clean all parts
in solvent and blow dry. Inspect polished surfaces of
spool and damper piston for damage that may cause
binding or leakage. Inspect spool bore in valve hous-
ing 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 brake valve
must be replaced. Check the free length of main pis-
ton spring. For the 1 1/4 inch valve, replace if less
than 1 15/16 in. (49.2 mm) long. For the 1 1/2 inch
valve, replace if less than 3 7/16 in. (87.3 mm) long.
Check the free length of the check valve spring.
Replace if less than 1 1/2 in. (38.1 mm) long.
1 1/2 in. valve
2. Inspect the 0.020 inch (0.5 mm) orifice in the end of
the spool to be certain it is open. On the 1 1/4 in.
valve, also inspect the pilot orifice to be certain it is
open.
ASSEMBLY
BACK-UP RING
BACK-UP RING
1. Install new O-rings and back-up rings on the spool and
damper pistons as shown. It is important that each
1 1/4 in. valve
O-RING
1 1/4 in. valve
O-RING
1 1/2 in. valve
back-up ring is on the correct side of its O-ring. Take
care not to cut the O-rings during assembly. Let the
spool and piston set for ten (10) minutes before
installing them into the brake valve housing. This will
allow the O-rings to return to their original size after
being stretched.
2. Install new O-rings on the plug and spool retainers.
3. Lubricate the spool and damper piston O-rings with
hydraulic oil. Carefully install the damper piston into
the spool. Carefully install the spool into the valve
housing. On either valve, always install the spool into
the valve body from the plug end, so the O-ring enters
the bore first. On the 1 1/4 inch valve, install the spool
spring and spring retainer. On the 1 1/2 inch valve,
install the spring seat, spool spring, damper piston
extension and spring retainer.
4. Install the check valve poppet, spring and check valve
retainer.
5. Install the motor drain check ball, spring and fitting.
6. On the 1 1/4 inch valve only, install the pilot orifice into
the "BR" port of the valve housing.
7. The brake valve is now completely assembled and
ready to be installed on the winch motor.
38
1 1/4 in. valve
1 1/2 in. valve