Drum Brake - Leading/Trailing Design

In the leading/trailing design drum brake system, the return springs hold both shoes against the wheel cylinder at the top and against the fixed anchor at the bottom. When the brakes are applied, the wheel cylinder moves both shoes out to contact the drum. The forward shoe wraps itself into the drum and self-energizes during forward application. With application in reverse, the rear shoe wraps itself into the drum providing self-energization.