Practice question

Why is heat the enemy of brake drums on long downgrades?

  1. Heat improves friction
  2. Heat causes drums to expand away from the linings (fade) and can crack the drums or burn the linings
  3. Heat freezes the air
  4. Heat strengthens metal

Answer: B — Heat causes drums to expand away from the linings (fade) and can crack the drums or burn the linings

The correct answer is shown above. Try the full quiz for additional practice.

Practice more: Colorado CDL Air Brakes Practice Questions - Colorado CDL Air Brakes Knowledge Test Exam →