TM 5-3805-263-14&P-3
Air from the air tank (6) goes through one-way check
SYSTEMS OPERATION
valve (16) to the control valve (17) for the parking brake.
When the safety lever is pulled to the rear, pressure air
When the machine is stopped and the safety lever is
goes through the control valve to quick release valve (7).
pushed to the PARK position, the transmission shift lever
Air then goes through the quick release valve into
is held in the NEUTRAL position. In an emergency, when
rotochamber (8). The pressure air moves the rod and
the machine is being operated, the safety lever can be
rod end. The rod end is connected to a lever on the front
pushed to the PARK position. This will engage the
of the transmission housing. This lever is connected to
parking brake and also move the transmission shift lever
the parking brake piston in the transmission. As the
to the NEUTRAL position.
rotochamber moves the rod end and the lever down, the
piston is turned to release the disc-type brake. The one-
way check valve prevents the parking brake from
engaging if air pressure to the control valve is low.
SAFETY LEVER FOR PARKING BRAKE IN
PARK POSITION
Accessory Circuits
Differential Lock
The machine is equipped with an oil activated
differential lock. The oil supply for the differential lock is
from the No. 6 clutch of the transmission. Part of the oil
ROTOCHAMBER FOR PARKING BRAKE
from the No. 6 clutch goes through a differential lock
IN BRAKE OFF POSITION
solenoid control valve mounted on the differential carrier.
10. Rotochamber.
The lock control valve is normally open (in LOCK
When the safety lever is pushed forward to the PARK
position) allowing oil to flow to the locking mechanism.
position, the inlet port in control valve (17) for the parking
The valve is closed (in UNLOCK position) by a solenoid
brake closes and the exhaust port opens to release the
controlled by a switch mounted on the operator's steering
air in the line to quick release valve (7). The exhaust
console panel. In UNLOCK position the solenoid is
port of the quick release valve then opens to release the
activated to stop the flow of oil to the locking mechanism
air in the rotochamber. With no pressure air in the
with the differential.
rotochamber, the spring force moves the rod and rod
Because oil is sent to the No. 6 clutch only in the first
end into the rotochamber. This moves the lever on the
four speeds of the transmission, the differential lock is
transmission to engage the parking brake.
engaged only when the transmission is in these speed
ranges.
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