Free CDL Air Brakes Practice Test
If your truck or bus has air brakes, you take the Air Brakes test from Section 5 of the CDL manual: compressors and governors, cut-in and cut-out pressures, spring brakes, slack adjusters, the seven-step air brake check and how to brake on a downgrade.
25 Air Brakes questions with three answer choices, scored at the real 80% pass mark (20 correct), with an explanation from the CDL manual for every answer.
Or start with a free Air Brakes drillTo test the service brakes, you wait for normal air pressure, release the parking brake, and move forward slowly before braking firmly. About how fast should you be going?
CDL Air Brakes test at a glance
- Who takes it
- Anyone who will drive a commercial vehicle with air brakes, including air over hydraulic brakes. Without it your license carries an air brake restriction.
- Passing score
- 80%
- Answer choices
- 3 per question
- Manual
- Section 5
Your state sets the number of questions from the federal question pool. Our full Air Brakes practice test has 25 questions, so you need 20 correct to reach 80%. 38 original Air Brakes questions rotate through it, so a second try is a different test.
What’s on the Air Brakes test
The test comes from Section 5 of the CDL manual. Our questions cover it in 2 topics, and your practice score report shows how you did in each one.
- Parts of the air brake system23 practice questions
- Inspecting and using air brakes15 practice questions
Take the full Air Brakes test
25 Air Brakes questions with three answer choices, scored at the real 80% pass mark (20 correct), with an explanation from the CDL manual for every answer.
Or start with a free Air Brakes drillFree Air Brakes practice drills
Ten questions with the explanation after each answer. Create a free account to save your results; each drill’s first attempt is free.
CDL Air Brakes questions
What happens if I skip or fail the CDL Air Brakes test?
Federal rules require an air brake restriction on your CLP or CDL (49 CFR 383.135), so you may not drive a commercial vehicle with full air brakes.
What is on the CDL Air Brakes test?
Section 5 of the CDL manual: the parts of an air brake system, dual air systems, inspecting the system including the air brake check, and using air brakes, from normal stops to emergency stops and downhill braking.
Ready for the DMV?
25 Air Brakes questions with three answer choices, scored at the real 80% pass mark (20 correct), with an explanation from the CDL manual for every answer.
Or start with a free Air Brakes drillOther CDL practice tests
Questions are written from Section 5 of the model CDL manual; rules from the federal regulations, checked October 2026: Texas Commercial Motor Vehicle Drivers Handbook (DL-7C, AAMVA model CDL manual, revised March 2026) · 49 CFR 383.25 Commercial learner’s permit · 49 CFR 383.71 Driver application and certification procedures · 49 CFR 383.91 Commercial motor vehicle groups · 49 CFR 383.93 Endorsements · 49 CFR 383.133 Test methods · 49 CFR 383.135 Passing knowledge and skills tests · TSA Hazmat Endorsement Threat Assessment Program.
Original independent practice. Not affiliated with or endorsed by FMCSA, AAMVA or any state licensing agency.