CDL General Knowledge TestDriving SafelyMedium
A commercial driver is performing a post-trip inspection. They notice that the vehicle's brake drums appear discolored, possibly blue or glazed, and there's a strong burnt smell. What does this condition most likely indicate?
- ANormal wear and tear from routine braking.
- BThe brakes have been properly adjusted and are working efficiently.
- CThe brakes have overheated, leading to potential brake fade.
- DThe brake linings are too thick, causing excessive friction.
Show answer & explanationAnswer & explanation
Correct answer: C. The brakes have overheated, leading to potential brake fade.
Blue or glazed brake drums, along with a burnt smell, are classic signs of brake overheating. Overheating can lead to brake fade, where the brakes lose effectiveness, and can cause damage to brake components.
Why the other options are wrong
- A. Normal wear does not typically cause blue discoloration or a burnt smell.
- B. Efficient brakes do not typically show signs of overheating like discoloration and burnt smell.
- D. Brake linings that are too thick would likely cause dragging or binding, not necessarily blue discoloration associated with overheating.
Brake Overheating Signs
Visual and olfactory indicators that a vehicle's brakes have been subjected to excessive heat, potentially compromising their performance and integrity.
- Blue or glazed appearance of brake drums/rotors.
- Strong, acrid, burnt smell.
- Can lead to brake fade and reduced stopping power.
Memory trick: Blue drums and burnt smell mean brake trouble's real!