Michigan State Brakes Certification Practice Exam

When installing brake shoe linings of different lengths, which shoe lining is traditionally smaller?

1. The secondary shoe lining

2. The primary shoe lining

3. The lining near the rear axle

4. The lining that faces the drum

The correct answer is: The primary shoe lining

When considering the installation of brake shoe linings, the primary shoe lining is traditionally smaller in length compared to the secondary shoe lining. This design is integral to the functioning of drum brakes. The primary shoe is responsible for initiating braking when the brake pedal is pressed, while the secondary shoe engages more fully during operation due to its larger size. The primary shoe lining being smaller allows it to provide an efficient initial contact with the brake drum while enabling the secondary shoe to take over and provide increased braking force. This is important for maintaining balance and effectiveness within the braking system. The secondary shoe’s larger surface area helps to enhance the overall braking force as it engages more directly with the drum during braking action. In contrast, lining near the rear axle or lining that faces the drum does not necessarily determine the size of the lining; rather, it's the functional design of the primary and secondary shoes that dictates their sizes in braking systems. This is essential knowledge for ensuring effective brake performance.