SUB-SECTION 5H
WINCH BRAKE VALVES
chamber. Pressure in the brake chamber will then release
Inspect the body and spool for damage. If either part is
the brake.
damaged, the complete valve should be replaced.
REMOVAL. To remove the winch brake valve, proceed as
5. Install a new back up ring and O-ring in the spool
follows:
qroove. The back up ring should be nearest the hole in the
end of the spool.
1. Clean the valve and surrounding area with a suitable
solvent.
6. Lubricate the spool and bore with clean hydraulic oil.
Then carefully install the spool with a slight turning
2. Disconnect the three hydraulic lines. Cap the lines and
motion. Push the spool into the body until 1/2" (12.7 mm)
plug the valve ports as each line is disconnected.
of spool is protruding from the body.
3. Remove the two attaching screws and slide the valve
7. Install the spring support and secure it with the screw.
back to disengage it from the linkage.
Hold the spool with a suitable drift pin and tighten the
screw.
REPAIR. Repair of this valve is limited to the replacement
8. Pull the spool out until the spring support seats against
of the O-ring and back up ring on the spool. To replace
these parts, proceed as follows (see Figure 5H-3):
the body. Then install the spring and plug.
1. Remove the plug and spring from the end of the valve.
INSTALLATION. Install the valve in the reverse order of
removal. Then adjust the actuating linkage as follows (see
2. Push the spool out the plug end of the body. Remove,
and discard the O-ring and back up ring.
1. Loosen the locknut and back out the setscrew in the
3. Insert a suitable drift pin in the hole at the end of the
actuating linkage.
spool to prevent the spool from turn while removing the
screw from the opposite end of the spool. Remove the
2. Then turn the setscrew in until it just touches the end of
screw and spring support.
the spool.
3. Lock the setscrew by tightening the locknut.
4. Wash all parts thoroughly with a suitable solvent.
Figure 5H-4. Linkage Adjustment
5H-3
