Chery automobile Service Manual page 314

1 Front wheel hub
2 Dust cover
3 Brake pad assy.
4 Dust boot
5 Guide rod
6 Bleeder valve screw
Structure of Front Wheel Disc Brake
The rotating component of front brake is the brake disc, which is fixed onto the wheel hub
and rotates together with the hub. The brake caliper bracket is a fixed component (integrated
with the steering knuckle). When braking, the piston pushes the friction pad adjacent to the
piston due to the hydraulic pressure, and makes the pad press the brake disc. Since the brake
caliper moves relatively on the guide rod of caliper bracket, the counterforce will push the
caliper together with friction pad to the other side of brake disc, until the forces applied on
both friction pads are equalized.
The piston gasket installed in the caliper housing is elastically deformed when braking, and
resumes the original shape, based on the elastic restoring force, and makes the piston return
back to its original position when the brake is released. When brake clearance exceeds the set
value due to the wear of friction pad, the piston will slide relatively with the gasket so as to
achieve the automatic adjustment of clearance.
Characteristics of Front Wheel Disc Brake
* Stable braking performance. The disc brake is generally free of the friction adding effect,
so the friction factor makes very limited influence on the braking performance, and the
brake stability of whole vehicle is considerably improved.
* Good water stability, i.e., its efficiency decrease is small after being soaked in water. The
brake lining of disc brake is with high unit pressure which is easy to squeeze out the water,
and, based on the centrifugal force, only the first or twice braking is required to resume the
original after water is squeezed out. And, for the drum brake, tenth braking or more is
required to resume the original.
* Lower possibility of forming the hot crack or hotspot under the high temperature than
that of the brake drum provided that the brake disc is not too thick.
* Smaller dimension and lighter weight than drum brake in case that their output moments
of braking force are the same.
* Extremely low thermal expansion in the thickness direction of brake disc, which isn't the
same as the thermal expansion of brake drum to make the clearance of brake increase
considerably and cause the too larger travel of brake pedal.
* Easy and automatic clearance regulation, and simple maintenance and repair operation.
7 Bolt
8 Bolt
9 Left caliper housing
10 Piston
11 Piston gasket
12 Piston dust cover
P-10
13 Piston damping washer
14 Bracket
15 Lock screw
16 Brake disc
17 Screw