Practice question

When you press the brake pedal in a vehicle with S-cam brakes, air pressure pushes out the rod and moves the:

  1. Slack adjuster.
  2. Axle.
  3. Brake drum.
  4. Alcohol evaporator.

Answer: A — Slack adjuster.

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

Practice more: District Of Columbia CDL Air Brakes Test 1 →