SWING BRAKE LOCK VALVES
SWING BRAKE LOCK VALVES
A. Loosen all the tube nuts on the tubes attached to the
SWING BRAKE LOCK VALVE (36Z361)
valve, but do not disconnect the nuts from the fit-
B. Tap each tube gently to break the oil tight connec-
The swing brake lock valve is located just below and to the
tion. This will allow any pressure trapped in the brake
rear of the instrument panel in the upper cab, and is used to
circuit to escape.
maintain the swing brake in the applied position when oper-
ated. This valve is a three way, two position, spool type
2. Disconnect the tubes attached to the valve.
valve which operates in the swing brake circuit as follows:
3. Remove the capscrews, lockwashers, and nuts which
secure the valve to the cab wall, and remove the valve. Be
The swing brake lock valve is installed between the
sure to hold the nuts, as they are not welded to the cab
swing brake valve and the swing brake. It operates
independently of the swing brake valve, and will over-
ride the swing brake valve, when operated.
When the control knob is pulled up, the spool is positioned
Repair of this valve is limited to the replacement of ring
so that the swing brake valve is connected to the swing
seals. To replace the ring seal, proceed as follows (see
brake. This allows the swing brake to be applied and re-
leased by the swing brake pedal.
1. Remove the snap rings at each end of the valve spool.
When the control knob is depressed, the spool is positioned
so that the swing brake valve is disconnected from the
2. Push the control knob in until the rear ring seal is ex-
swing brake, and the swing brake is connected to tank. This
posed. Remove the rear ring seal.
allows the pressure in the swing brake circuit to vent to
3. The valve spool may now be removed from the valve
tank, thereby allowing the brake springs to apply the swing
body. Remove the front ring seal.
brake. The swing brake will remain in the applied position
until the control knob of this valve is pulled up.
4. To prevent cutting the front ring seal on sharp edges,
wrap the spool with 3 or 4 layers of glossy paper, leaving
only the front seal groove exposed. Slids the front ring seal
on from the rear of the spool over the paper and into the
To remove the swing lock valve, proceed es follows:
front seal groove.
1. Depress the control knob to vent any pressure which
5. Apply clean grease to the new seal. Remove the paper
may exist in the swing brake circuit. If the knob cannot be
and insert the spool in the valve body, and with a rotating
depressed, proceed as follows, otherwise proceed to Step 2.