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page 27
T-12-T
Maintenance
2.8
Electric Brake System
Operation
The electric brakes on your trailer are similar to the drums brakes on your automo-
bile. The basic difference is that your automotive brakes are actuated by hydraulic
pressure while the electric brakes are actuated by an electromagnet. With all of the
brake components connected into the system, the brake will operate as follows:
1. When the electrical current is fed into the system by the controller, it flows through
the electromagnets in the brakes. The high capacity electromagnets are energized and
are attracted to the rotating armature surface of the drums which moves the actuating
levers in the direction that the drums are turning.
2. The resulting force causes the actuating cam block at the shoe end of the lever to
push the primary shoe out against the inside surface of the brake drum. The force
generated by the primary shoe acting through the adjuster link then moves the second-
ary shoe out into contact with the brake drum.
Primary Shoe
Actuating Lever Arm
Backing Plate
Retractor Springs
Adjusting Screw
Spring
Shoe Hold Down
Spring
Secondary Shoe
Magnet
Adjusting Screw
M
A
I
N
T
E
N
A
N
C
E
