Drum Brakes; Brake Light Switch; Removal & Installation - Ford Ranger Maintaince And Repair Manual

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The sliding and floating designs are quite similar. In fact, these two types are often lumped together. In both
designs, the pad on the inside of the rotor is moved into contact with the rotor by hydraulic force. The caliper,
which is not held in a fixed position, moves slightly, bringing the outside pad into contact with the rotor.
There are various methods of attaching floating calipers. Some pivot at the bottom or top, and some slide on
mounting bolts. In any event, the end result is the same.

DRUM BRAKES

Drum brakes employ two brake shoes mounted on a stationary backing plate. These shoes are positioned
inside a circular drum which rotates with the wheel assembly. The shoes are held in place by springs. This
allows them to slide toward the drums (when they are applied) while keeping the linings and drums in
alignment. The shoes are actuated by a wheel cylinder which is mounted at the top of the backing plate. When
the brakes are applied, hydraulic pressure forces the wheel cylinder's actuating links outward. Since these
links bear directly against the top of the brake shoes, the tops of the shoes are then forced against the inner
side of the drum. This action forces the bottoms of the two shoes to contact the brake drum by rotating the
entire assembly slightly (known as servo action). When pressure within the wheel cylinder is relaxed, return
springs pull the shoes back away from the drum.
Most modern drum brakes are designed to self−adjust themselves during application when the vehicle is
moving in reverse. This motion causes both shoes to rotate very slightly with the drum, rocking an adjusting
lever, thereby causing rotation of the adjusting screw. Some drum brake systems are designed to self−adjust
during application whenever the brakes are applied. This on−board adjustment system reduces the need for
maintenance adjustments and keeps both the brake function and pedal feel satisfactory.
WARNING
Clean, high quality brake fluid is essential to the safe and proper operation of the brake system. You should
always buy the highest quality brake fluid that is available. If the brake fluid becomes contaminated, drain and
flush the system, then refill the master cylinder with new fluid. Never reuse any brake fluid. Any brake fluid
that is removed from the system should be discarded.

Brake Light Switch

REMOVAL & INSTALLATION
DISC BRAKES 973