Michigan State Brakes Certification Practice Exam

If rear brakes are dragging after new linings are installed, what is the likely cause?

1. The shoes are too long

2. The technician adjusted the shoes with a stuck parking brake cable

3. The drums were not machined correctly

4. The brake fluid is contaminated

The correct answer is: The technician adjusted the shoes with a stuck parking brake cable

When rear brakes are dragging after new linings are installed, a common cause is related to the interaction between the brake shoes and the parking brake mechanism. If the technician adjusts the shoes while the parking brake cable is stuck, the adjustment may not allow the shoes to retract properly. This improper adjustment can lead to excess friction against the brake drum, causing the brakes to drag. In this scenario, if the parking brake cable is immobilized, it prevents the brake shoes from being fully released. As a result, the shoes remain in contact with the drum even when the brakes are not engaged, leading to overheating and premature wear of the brake components over time. This highlights the importance of ensuring that all parts of the braking system, including the parking brake, are functioning correctly during maintenance or installation of new brake linings. In contrast, issues such as the shoes being too long would lead to fitment problems rather than dragging specifically after installation. Similarly, if the drums were not machined correctly, it might create uneven contact but not necessarily relate directly to the adjustment procedure after installation. Lastly, contaminated brake fluid is typically a concern for hydraulic systems and would not singularly cause dragging in the context of a mechanical brake adjustment.