BRAKE SYSTEM
The air brake system includes a service brake, an
emergency brake, a parking brake and a digging
brake.
W A R N I N G
Do not drive while low air indicator is
flashing. If light comes on while carrier is
moving, stop carrier in a safe area as soon
as possible. If carrier will not maintain
proper brake pressure notify maintenance
personnel immediately for repair of
condition.
W A R N I N G
Wear safety belt to avoid-beIng thrown
from driver ’s seat during braking
emergency.
NOTE:
Lines in following simplified brake system
diagrams show pressure and exhaust air flow under
various system conditions.
Service brake
The basic system includes two reservoirs to store
and furnish air pressure for service brake operation.
One reservoir supplies pressure to apply brakes to
the wheels of the front axle and the other supplies
pressure to apply brakes to the wheels of the
forward and rear tandem axles. Depressing the
brake treadle causes air pressure to be applied to
brake actuators of all wheels simultaneously.
Do not “fan” the brake valve treadle. A long
series of rapid brake applications can
reduce system pressure to a point where
effective service braking will be lost until
air compressor can restore pressure.
The operating pressure range for service brakes is 60
to 125 psi (414/862 kPa). Two pressure gages are
furnished to indicate pressure in front and rear
portions of the system. The gage on top indicates
pressure available for front axle brakes and the gage
on the bottom indicates pressure available for tandem
axle brakes. If pressure in either portion of the system
falls below safe operating range, the low air indicator
light will flash.
1 8
Emergency brake
The emergency brake functions only when air
pressure has been lost from some portion of the dual
brake system. Emergency brakes are applied by
normal foot pressure on the brake treadle.
W A R N I N G
Emergency brakes will not stop carrier in
as short a distance as the service brakes.
If air pressure is lost from the front portion of the
dual brake system, normal actuation of the brake