CDL (Commercial Driver)
CDL Air Brakes Practice Test 14
Free — no payment neededPractice betaLevel: Mixed
20 original CDL Air Brakes questions based on the federal motor carrier safety rules (49 CFR). Practice test, not affiliated with any government agency. Practice beta.
Created by AI
Practice test, not affiliated with any government agency. Original questions written from public sources, checked by a second AI reviewer and automated checks. Rules change; confirm with the official handbook. Available in 2 languages (translations are machine-made and checked automatically).
Before you start
- Questions
- 20 multiple-choice questions, one at a time
- Time
- About 12 minutes. Untimed — take as long as you need.
- Pass mark
- 16 out of 20 correct (80%)
- Feedback
- Your score, the correct answers and short explanations when you finish
- Account
- Not needed. Your answers stay in this browser.
What this test covers
Inspecting air brakesUsing air brakesAir brake system partsDual air systems
Preview the first question
Before checking slack adjusters under the vehicle, what should you do first?
- Chock the wheels and release the parking brake
- Drain all air tanks to zero
- Put the transmission in high gear
- Set the parking brake and leave the engine running at high idle
Answers are revealed on the results page after you finish.