BRADEN CH330, Installation Maintenance And Service Manual

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  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 valve must be 

replaced as these parts are not serviced separately. 

Check the free length of the main piston spring.  For 

the 1-1/4-inch valve, replace if less than 1-15/16 inches 

(49.2 mm) long.  For the 1-1/2-inch valve, replace if 

less than 3-7/16 inches (87.3 mm) long.  Check the free 

length of the check valve spring.  Replace if less than 

1-1/2 inches (38.1 mm) long.

1-1/4-inch Valve

1-1/2-inch 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-inch valve, 

also inspect the pilot orifice to be certain it is open.

ASSEMBLY

1. Install new O-rings on the plug and spool retainers.

1-1/4-inch Valve

1-1/2-inch Valve

2. Install new O-rings and backup rings on the spool and 

damper pistons 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 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.

1-1/4-inch Valve

1-1/2-inch Valve

3. Lubricate the spool and damper piston O-rings with hy-

draulic 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 so the O-ring enters the bore first, or the plug end 

of the valve body.  Install the plug.  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 

spring 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 brake release port on the valve housing.

7. The brake valve is now complete and ready to be in-

stalled on the winch motor.

BACK-UP RING

O-RING

O-RING

BACK-UP RING