Free Idaho Air Brakes CDL Practice Test
7 real Air Brakes questions from the same bank our students use. No account, no email needed. You see the correct answer after each question, and your score at the end.
Take the Idaho Air Brakes test
Air Brakes is a restriction removal rather than an endorsement. Most tractor-trailers and many straight trucks use air brakes, so without it your license is issued barring you from the vehicles most employers run.
- 7 questions, from the 57-question Air Brakes bank, one for each key manual topic
- Practice mode: the correct answer and manual reference show after each question
- 80% is a pass, the same standard as the real Idaho CDL knowledge test
Takes about 3 minutes. Keyboard: A to D to answer, Enter for next.
At the end you get your score, the correct answer for anything you missed, and the CDL manual section to go back to. No account needed, and you can retake it as often as you like.
Already included in Idaho Class B CDL Study Material and Idaho Class A CDL Study Material. On its own it is Idaho CDL Air Brakes Study Material. Not sure what you need? The CDL Selector works it out from a few questions.
About the Idaho Air Brakes test
The questions come from the Idaho CDL manual, they are multiple choice, and you need 80% to pass, the same standard as every other CDL knowledge test. Idaho Transportation Department gives it, and you sit it on top of the General Knowledge test rather than instead of it.
The air brake test is not an endorsement. It is the opposite: pass it and your license is issued without the restriction that would otherwise bar you from driving any vehicle with air brakes. Most tractor-trailers and a great many straight trucks have them, so for most drivers this is not optional in practice. Skip it, or fail it, and the restriction stays on the license.
What it covers
Our 7 free questions and the full 57-question Air Brakes bank are drawn from these manual sections:
- The Parts of an Air Brake System
- Dual Air Brake
- Inspecting Air Brake Systems
- Using Air Brakes
Every CDL applicant also sits the General Knowledge test, whatever class they are working toward. Try the free Idaho CDL permit practice test, or see which Idaho CDL endorsements you need.
What Idaho requires
- The CLP must be held at least 14 days before the skills test and is valid for one year.
- Two separate skills-test payments are made: $10 to the county and the examiner's fee directly to the examiner at the test.
- Your DOT medical examiner must be on the FMCSA National Registry.
- Idaho's ten-step CDL guide from ITD lays out the whole process in order.
Checked against Idaho Transportation Department on September 16, 2026. Rules change, so confirm anything that affects your booking before you travel.
Try another free CDL practice test
Each one is a different knowledge test, with real questions from the same bank our students use. No account and no email needed for any of them.
- Free CDL Permit practice test 10 questions
- Free Combination Vehicles practice test 8 questions
- Free HazMat practice test 6 questions
- Free Tanker practice test 6 questions
- Free Passenger practice test 6 questions
- Free School Bus practice test 8 questions
- Free Doubles & Triples practice test 6 questions
Where to go next
Work out which license class you need, then study the test that goes with it:
- Idaho CDL classes: what Class A, B and C each let you drive.
- Idaho CDL endorsements: H, N, P, S, T and X, and who needs each.
- CDL requirements: the age, medical, ELDT and permit steps around the knowledge test.
- The CDL skills test: what comes after the knowledge tests, and the 14 day permit rule.
- What CDL do I need, by vehicle: the class and the tests for a dump truck, box truck, school bus, tanker and more.
- Idaho CDL study material: the full study guides, practice tests and narrated audio.
Other free CDL practice tests
Each CDL knowledge test is a separate exam, and every one of them has a free practice test here:
- Free CDL Permit Practice Testthe permit test
- Free Combination Vehicles CDL Practice Testa core Class A test
- Free HazMat CDL Practice Testthe H endorsement
- Free Tanker CDL Practice Testthe N endorsement
- Free Passenger CDL Practice Testthe P endorsement
- Free School Bus CDL Practice Testthe S endorsement
- Free Doubles & Triples CDL Practice Testthe T endorsement
See all eight free CDL practice tests →
Common questions
How long is the air brake test?
The number of questions is set by your state, not nationally. Federal rules require each knowledge test to draw a set number of questions from an approved pool, but they do not fix a count per test, so the length is whatever Idaho Transportation Department uses. Whatever the length, 80% is the pass mark.
Do I have to take the air brake test?
Only if you want to drive a vehicle with air brakes, which in practice means most commercial vehicles. It is not an endorsement you add: if you do not pass it, your license is issued with a restriction barring you from air-braked vehicles. You can remove that restriction later by passing the test.
What does the air brake test cover?
The air brake section of the CDL manual: how the system builds and holds pressure, the dual air brake system, the warning devices, the inspection steps specific to air brakes, and how brake lag changes your stopping distance compared with hydraulic brakes.
Does the restriction come off automatically?
No. The restriction stays until you pass the air brake knowledge test and, where your state requires it, take the skills test in a vehicle equipped with air brakes. Idaho Transportation Department can confirm what it asks for.