Drum Brake System: Description and Operation

Drum Brake System

This drum brake is an advanced leading/trailing shoe design.
The advanced design operates with less total parts. The drum brake performance is equivalent to other drum brakes while providing improved reliability. The operation and servicing of the advanced design brake is much simpler than traditional drum brakes.
This brake system employs a single universal spring. The single universal spring holds both the shoe and the lining assemblies to the backing plate. The spring also acts as the return spring for both the shoe and the lining assemblies. Force from the brake shoes is transferred through the fixed anchor and backing plate to the axle flange. Adjustment is automatic and occurs on any service brake application. Also, with leading/trailing brakes, it is normal for the leading (front) shoe to wear at a faster rate than the trailing (rear) shoe. Do not switch the position of shoes that have been in service; this may render the self adjustment feature inoperative and result in increased pedal travel.