Automobile & Light Truck Certification Test A5 BrakesDrum Brake Diagnosis and RepairMedium
When reassembling a drum brake system, a technician applies a thin layer of high-temperature grease to the contact points between the brake shoes and the backing plate. What is the PRIMARY reason for this practice?
- ATo ensure electrical conductivity for ABS sensors.
- BTo prevent rust formation on the backing plate.
- CTo help dissipate heat from the brake shoes.
- DTo reduce friction and prevent squeaks or groans during braking.
Show answer & explanationAnswer & explanation
Correct answer: D. To reduce friction and prevent squeaks or groans during braking.
Applying a thin layer of high-temperature grease or anti-squeal compound to the shoe-to-backing plate contact points reduces friction, allowing the shoes to slide smoothly. This prevents noise (squeaks, groans) and ensures consistent shoe movement, which is crucial for proper braking performance.
Why the other options are wrong
- A. Brake components are not generally involved in ABS sensor electrical conductivity.
- B. While it may offer some rust protection, the primary purpose is not rust prevention.
- C. Grease is an insulator and would hinder heat dissipation, not help it.
Brake Lube Points
Specific contact points in a drum brake system where high-temperature lubricant is applied to facilitate smooth movement and prevent noise.
- Applied to shoe-to-backing plate pads.
- Reduces friction and noise.
- Must be high-temperature grease.
Memory trick: Lube the slides, where the shoe glides, no squeak hides.