192 Auto Brakes
Figure 12-1. A—Cross-sectional view of a typical single piston, sliding (floating) disc brake assembly. Note the ventilated rotor (disc).
B—Front view. Note the minimum thickness numbers stamped on the hub portion of the disc. (General Motors)
Minimum
thickness
Outboard shoe
and pad
Ventilated
rotor
Piston seal
Shoe retainer
spring
Caliper
housing
Cylinder
bore
Brake fluid
inlet port
Piston
Boot
Mounting
bracket
Rotor cooling fins
Inboard shoe
and pad
A
B
This chapter is designed to provide a clear under-
standing of front and rear disc brake operation. Caliper
hydraulic components were covered in Chapter 5. This
chapter covers all major types of disc brake rotor and
caliper designs and related parts. Studying this chapter
will prepare you for the service and repair information in
Chapter 13.
Disc Brake Rotor
The job of the disc brake rotor is to provide a smooth
braking surface for the pads to contact. When the station-
ary pads contact the spinning rotor, the resulting friction
slows the rotor and stops wheel rotation. Much of the
resulting frictional heat is absorbed and dissipated by the
rotor. Figure 12-1 shows a typical rotor and pad assembly.