Free Georgia DMV CDL — Air Brakes Practice Test 2026
The Georgia CDL — Air Brakes knowledge test has ~25 questions, and you need ~20 correct (80%) to pass. Practice free with questions written from the official Georgia driver handbook — every one has a clear explanation, and you can retake as often as you like with no sign-up.
Content reviewed against official driver handbooks · August 12, 2026
What's on the Georgia written test
The Georgia CDL — Air Brakes knowledge test has ~25 questions; you need ~20 correct (80%) to pass.
Based on the official Georgia exam format — always confirm current details with your state DMV.
Practice by topic
Focus on one area at a time — each topic has its own set of Georgia practice questions.
How to pass the first time
- Read the official Georgia driver handbook at least once before test day.
- Practice by topic to find your weak spots, then fix them.
- Take full-length practice tests until you pass comfortably every time.
- Read every explanation — understanding beats memorizing.
Georgia CDL — Air Brakes test — frequently asked questions
How many questions are on the Georgia CDL — Air Brakes test?
The Georgia CDL — Air Brakes knowledge test has ~25 questions, and you need ~20 correct (80%) to pass. Our practice tests mirror that format.
How many questions can I miss on the Georgia CDL — Air Brakes test?
You can miss up to ~5 of the ~25 questions and still pass — you need ~20 correct, which is 80%.
Can I retake the practice test?
Yes — practice as often as you like, completely free. The questions and answer choices are shuffled each time.
Can I take the Georgia practice test in Spanish?
Yes. Every question here is available in English and Spanish — switch languages anytime. Many states also offer the real knowledge test in languages other than English; confirm what Georgia offers with your DMV.
Can I practice on my phone?
Yes. The practice tests work in any mobile or desktop browser — no app or sign-up needed — so you can study anywhere.
Are these the real DMV test questions?
No. Our questions are original, written from the current official Georgia driver handbook to match the real test's topics and style. We are not affiliated with any DMV or government agency.
What's the best way to study?
Read the Georgia driver handbook, practice by topic to target weak areas, and finish with full-length tests until you consistently pass.
Other Georgia practice tests
Take the CDL — Air Brakes test in another state
Every Georgia question is written from the official Georgia driver handbook and checked against its current edition. DMV Test Free is a free, independent study resource — not affiliated with any DMV or government agency. About DMV Test Free
Georgia CDL — Air Brakes questions with answers
20 sample questions from the Georgia CDL — Air Brakes question bank — each with the correct answer, a short explanation, and the section of the official handbook it comes from.
Show all 20 questions with answers
1. What is the main advantage of the dual air brake system used on most newer heavy vehicles?
Correct answer: If one system fails, the other can still provide braking on some wheels
A dual air system has two separate halves — primary and secondary — sharing one set of controls. If one half loses pressure, the other can still operate brakes on some of the wheels, giving you a chance to stop.
2. The correct rhythm for snub braking on a long downgrade is to:
Correct answer: Slow about 5 mph below your safe speed, release, then reapply when back at safe speed
Once you reach your safe speed, apply the brakes firmly enough to feel a definite slowdown of about 5 mph below that speed, then release. When speed climbs back to your safe speed, repeat the cycle.
3. For a normal stop in an air-braked vehicle, the manual says to press the brake pedal so that:
Correct answer: The vehicle comes to a smooth, safe stop
For a normal stop, push the pedal down and control the pressure so the vehicle comes to a smooth, safe stop. With a manual transmission, do not push the clutch in until engine rpm nears idle.
4. What must a CDL applicant do to be licensed WITHOUT an air brake restriction?
Correct answer: Pass the air brakes knowledge test and take the skills test in a vehicle with full air brakes
To avoid the restriction, you must pass the air brakes knowledge test and complete the skills test in a vehicle equipped with a full air brake system, demonstrating the air brake inspection during the test.
5. When leaving your air-braked vehicle unattended, what does proper (and required) practice call for?
Correct answer: Applying the parking brakes, or chocking the wheels when the brakes are very hot or wet in freezing weather
Any time you park, use the parking brakes (with the exceptions for very hot or wet-freezing brakes, when you use wheel chocks instead). Never leave the vehicle relying only on the service brake pedal or the transmission.
6. For the static leakage test on a single vehicle — engine off, brakes released, fully charged system — the air pressure loss must be less than:
Correct answer: 2 psi in one minute
After the initial pressure drop settles, a single vehicle should lose less than 2 psi in one minute with the brakes released (less than 3 psi per minute for combination vehicles). More than that means a leak that must be fixed before driving.
7. What is the main cause of brake fade on a long downgrade?
Correct answer: Excessive heat from using the brakes too much instead of engine braking
Relying on the service brakes instead of engine braking causes excessive heat. Overheated drums expand and linings lose friction, so the brakes provide less and less stopping power — and severe overheating can cause permanent damage.
8. Which distance is unique to air-braked vehicles when figuring total stopping distance?
Correct answer: Brake lag distance
All drivers face perception, reaction, and braking distance. Air-braked vehicles add a fourth element — brake lag distance — because air must flow through the lines before the brakes act.
9. In Georgia, what happens if you complete your CDL skills test in a vehicle that is not equipped with air brakes?
Correct answer: Your CDL is issued with a restriction barring you from air-braked vehicles
If your skills test vehicle lacks air brakes, Georgia DDS issues your CDL with an air brake restriction, and you may not legally drive a CMV equipped with air brakes until the restriction is removed.
10. Under safety regulations, the brakes on the front wheels of a truck or tractor must be:
Correct answer: In working order like the brakes on every other wheel
Working brakes are required on all wheels. Front wheel brakes provide effective stopping power under almost all conditions, and the old practice of cutting them out or limiting them is not permitted as a substitute for proper braking.
11. The governor stops the air compressor from pumping once the tanks reach the cut-out level, which is around:
Correct answer: 125 psi
The governor controls when the compressor pumps air. When tank pressure climbs to the cut-out level of about 125 psi, the governor stops the compressor from pumping more air.
12. Your brakes have overheated and are failing partway down a mountain grade, and an escape ramp is marked ahead. What should you do?
Correct answer: Use the escape ramp — it is built to stop runaway vehicles safely
Escape ramps use loose material or an upgrade to stop a runaway vehicle safely. If your brakes fail on a downgrade, use the escape ramp — it greatly reduces the chance of injury and vehicle damage compared to any alternative.
13. During stab braking in an emergency, when do you release the brake pedal — and when do you press it again?
Correct answer: Release when the wheels lock up; reapply fully once the wheels start rolling again
In stab braking you apply the brakes fully, release when the wheels lock up, and apply fully again as soon as the wheels start rolling. It can take up to a second for wheels to start rolling after you release.
14. Which warning equipment is legally required on every vehicle with air brakes?
Correct answer: A low air pressure warning signal
All air-braked vehicles must have a low air pressure warning signal — a light, buzzer, or wig wag — that activates before pressure falls below the required level, so the driver can stop before the brakes stop working normally.
15. Some air brake systems include an alcohol evaporator. What job does it perform?
Correct answer: It puts alcohol into the system to help keep ice from forming in valves and lines
The alcohol evaporator introduces alcohol into the air system, which reduces the risk of ice forming inside air brake valves and lines in cold weather. Ice inside the system can cause brake failure.
16. Some dash-mounted control handles let you put the spring brakes on a little at a time. Why is that gradual action useful?
Correct answer: It lets you meter the spring brakes yourself if the service brake system quits
A modulating valve is spring-loaded, so the farther you move the lever the harder the spring brakes grab. That feel lets a driver hold the vehicle under control by hand when the normal foot-brake system has failed.
17. Add together perception distance, reaction distance, brake lag distance, and braking distance for an air-braked vehicle at 55 mph on good pavement. The total is:
Correct answer: Over 450 feet
At 55 mph under good conditions, the total stopping distance for a vehicle with air brakes is over 450 feet — perception, reaction, and brake lag all add distance before effective braking even begins.
18. Which instrument tells you how much air pressure is currently stored in your air tanks?
Correct answer: The supply pressure gauge
Every air-braked vehicle has a supply pressure gauge that shows the pressure available in the air tanks. Vehicles with dual air systems have a gauge (or two gauges) for each half of the system.
19. Why should you avoid pressing the brake pedal down while the spring brakes are applied?
Correct answer: The combined spring and air pressure forces could damage the brakes
The forces of the springs and the service brake air pressure can add together and damage the brakes. Many vehicles have valves to prevent this, but you should not rely on them.
20. At 55 mph, roughly how much extra distance does brake lag alone add to your stop compared to a vehicle with instant brakes?
Correct answer: About 32 feet
At 55 mph on dry pavement, the roughly 0.4-second brake lag adds about 32 feet of travel before the brakes even begin to slow the vehicle.