Automobile & Light Truck Certification Test A5 BrakesDrum Brake Diagnosis and RepairMedium
A technician is performing a drum brake service. After removing the drum, they notice that the brake shoe hold-down springs appear weak and stretched. What is the MOST likely consequence of this condition?
- AIncreased parking brake lever travel
- BUneven brake shoe wear and noise
- CExcessive brake pedal effort
- DPremature wheel cylinder failure
Show answer & explanationAnswer & explanation
Correct answer: B. Uneven brake shoe wear and noise
Weak or stretched hold-down springs allow the brake shoes to move excessively laterally or radially within the drum. This improper positioning can lead to the shoes not contacting the drum evenly, causing uneven wear, vibration, and various noises (e.g., clunking, rattling) during braking or driving over bumps.
Why the other options are wrong
- A. Parking brake lever travel is primarily affected by cable slack or adjuster issues, not hold-down springs.
- C. Excessive brake pedal effort is typically related to power assist, master cylinder, or severely worn linings, not hold-down springs.
- D. Hold-down springs do not directly influence wheel cylinder function or failure.
Hold-Down Spring Function
Springs that secure the brake shoes against the backing plate, preventing lateral movement and ensuring proper alignment with the drum.
- Prevents shoe rattling and noise
- Ensures even shoe-to-drum contact
- Weak springs lead to uneven wear and instability
Memory trick: Loose shoes on the drum, noise will come.