Drum Brake System: Description and Operation

The rear drum brake assembly is a leading/trailing design. When the brakes are applied, the wheel cylinder pistons move both shoes out to contact the drum with enough energy to overcome the rotation of the wheels, slowing and, with continued application, stopping the vehicle. Adjustment for both the leading and trailing shoes and linings is automatic when the brakes are applied. It is normal for the leading shoe to wear at a faster rate than the trailing shoe.