1-21. COMPRESSED AIR AND AIR-HYDRAULIC BRAKE SYSTEM OPERATION (Contd)
b. Air-Hydraulic Brake System Operation.
A BRAKE PEDAL - Operator control for slowing and stopping vehicle. Applies force through brake
linkage to master cylinder to actuate vehicle brakes.
B BRAKE LINKAGE - Transmits brake pedal force to master cylinder.
MASTER CYLINDER Stores brake fluid and is the filling location for adding brake fluid.
C
Converts force from brake linkage into hydraulic pressure.
D AIR-HYDRAULIC UNIT - Combines hydraulic pressure from master cylinder and air pressure
from compressed air system to apply increased hydraulic pressure to the vehicle brakes.
E HYDRAULIC BRAKE LINES - Direct brake fluid under hydraulic pressure to all six wheel
cylinders.
F WHEEL CYLINDER - Converts hydraulic pressure into mechanical force to press brakeshoes
against surface of brakedrum.
G BRAKEDRUM - Encloses wheel cylinder and brakeshoes, and provides a surface for brakeshoes
to press against.
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