Georgia CDL Air Brakes Practice Test

The Georgia CDL Air Brakes test is a multiple-choice knowledge test you take for your commercial learner's permit. Georgia Department of Driver Services (DDS) says you need 80% to pass (source).

Last updated Oct 15, 2026. FirstTry CDL is a CDL permit test prep site by Hive Asset Group, LLC.

By Scott Wilder, Editor

Last reviewed against the Georgia CDL manual on October 15, 2026

Scott Wilder on X | scottwilderhq.com

FirstTry CDL is a CDL permit test prep site by Hive Asset Group, LLC. It offers free exam-style practice tests built from the official CDL manual. FirstTry CDL is not affiliated with any DMV, FMCSA or government agency. Practice questions are exam-style questions built from the official CDL manual, not actual test questions.

Georgia CDL permit facts

What	What Georgia says	Source
Air Brakes pass mark	80%	Official page
CLP fee	$10	Official page
CLP validity	365 days (for permits issued on or after July 1, 2021)	Official page
Knowledge test retest wait	2 days after the first failure and any later failure	Official page
Test languages	You must be able to read and understand English, and all documents must be in English. The DDS manual says road signs and driving tests are in English only. Which languages the CDL knowledge tests come in is not stated on the official pages.	Official page

20 question Air Brakes practice test

1. How does a manual reset wig wag get back out of your view?
1. A. It rises out of view by itself
2. B. You must place it out of view by hand
3. C. The buzzer resets it
4. D. It resets when the engine starts
Show answer
Answer: B. You must place it out of view by hand
A manual reset wig wag must be placed in the out of view position by the driver.
From the official CDL manual, section 5.1.11.
2. How do you test the parking brake in the final air brake check?
1. A. Set it and gently pull against it in a high gear
2. B. Set it and rev the engine with the transmission in neutral
3. C. Release it and tap the brake pedal at 20 mph
4. D. Set it and gently pull against it in a low gear
Show answer
Answer: D. Set it and gently pull against it in a low gear
You put the parking brake on and gently pull against it in a low gear to see that it holds.
From the official CDL manual, section 5.3.3.
3. During the spring brake check, the parking brake knob pops out at 30 psi. What does this show?
1. A. A defect, because it should pop out at 85 psi
2. B. Normal, because it is within the 20 to 45 psi range
3. C. A defect, because it should stay in until 10 psi
4. D. A defect, because it should pop out at 55 psi
Show answer
Answer: B. Normal, because it is within the 20 to 45 psi range
Popping out at 30 psi is within the 20 to 45 psi range, so the spring brakes are coming on as they should.
From the official CDL manual, section 5.4.7.
4. During the walk-around, which brake lining condition is a defect?
1. A. Covered with a light layer of brake dust
2. B. Showing normal wear but still thick enough
3. C. Loose or soaked with oil or grease
4. D. Slightly darker than the brake drum
Show answer
Answer: C. Loose or soaked with oil or grease
The manual says linings must not be loose, soaked with oil or grease, or dangerously thin.
From the official CDL manual, section 5.3.2.
5. Which kind of brakes work instantly, with no brake lag?
1. A. Drum brakes with air
2. B. Spring brakes
3. C. Hydraulic brakes
4. D. Air brakes
Show answer
Answer: C. Hydraulic brakes
The manual says hydraulic brakes work instantly.
From the official CDL manual, section 5.4.4.
6. What can ABS help you do in a hard stop?
1. A. Steer around an obstacle while braking
2. B. Always stop in a shorter distance
3. C. Follow closer to the vehicle ahead
4. D. Skip the use of engine braking on grades
Show answer
Answer: A. Steer around an obstacle while braking
With ABS you may or may not stop faster, but you should be able to steer around an obstacle while braking.
From the official CDL manual, section 5.4.2.
7. In a dual air brake system, what is the first system called?
1. A. The secondary system
2. B. The main system
3. C. The emergency system
4. D. The primary system
Show answer
Answer: D. The primary system
The first system is called the primary system and the other is the secondary system.
From the official CDL manual, section 5.2.
8. On older vehicles, the low air warning may come on before pressure falls below what?
1. A. The pressure at which the governor cuts in
2. B. A fixed 20 psi on every vehicle
3. C. One half of the governor cutout pressure
4. D. The pressure at which the safety valve opens
Show answer
Answer: C. One half of the governor cutout pressure
For older vehicles the manual gives one half of the compressor governor cutout pressure.
From the official CDL manual, section 5.1.11.
9. How do you open a manually operated air tank drain valve?
1. A. Press the brake pedal until the air stops
2. B. Push in the yellow parking brake knob
3. C. Turn it a quarter turn or pull its cable
4. D. Turn it several full turns with a wrench
Show answer
Answer: C. Turn it a quarter turn or pull its cable
Manual drain valves work by a quarter turn or by pulling a cable.
From the official CDL manual, section 5.1.4.
10. Why should you never push the brake pedal down when the spring brakes are on?
1. A. The springs and air together could damage the brakes
2. B. It lets compressed air out of the tanks
3. C. It releases the spring brakes at once
4. D. It turns off the low air pressure warning
Show answer
Answer: A. The springs and air together could damage the brakes
Springs and air pressure pushing together could damage the brakes.
From the official CDL manual, section 5.1.15.
11. Some buses have a separate air tank tied to dual parking control valves. What is it for?
1. A. Releasing the spring brakes to move in an emergency
2. B. Filling the service brake tanks more quickly
3. C. Holding the spring brakes on while the bus is parked
4. D. Running the low air pressure warning signal
Show answer
Answer: A. Releasing the spring brakes to move in an emergency
The separate tank can release the spring brakes so the vehicle can be moved in an emergency.
From the official CDL manual, section 5.1.15.
12. What is brake lag?
1. A. The time it takes you to see a hazard
2. B. The time it takes you to move your foot to the pedal
3. C. The time it takes for the brakes to work after you push the pedal
4. D. The distance the vehicle travels while the brakes are slowing it
Show answer
Answer: C. The time it takes for the brakes to work after you push the pedal
Brake lag is the time required for the brakes to work after the brake pedal is pushed.
From the official CDL manual, section 5.4.4.
13. Air brake truck tractors built on or after what date must have ABS?
1. A. March 1, 1975
2. B. March 1, 1997
3. C. March 1, 1998
4. D. March 1, 2005
Show answer
Answer: B. March 1, 1997
Truck tractors with air brakes built on or after March 1, 1997 must have ABS.
From the official CDL manual, section 5.1.16.
14. How does ABS help you keep control during hard braking?
1. A. It adds extra air pressure to the brakes
2. B. It applies the spring brakes on slippery roads
3. C. It removes brake lag
4. D. A computer senses wheel lockup and lowers brake pressure
Show answer
Answer: D. A computer senses wheel lockup and lowers brake pressure
The ABS computer senses impending lockup and reduces braking pressure to a safe level so you keep control.
From the official CDL manual, section 5.4.2.
15. On large buses, low pressure warning devices commonly signal at about what pressure?
1. A. 55 psi
2. B. 20 to 30 psi
3. C. 125 psi
4. D. 80 to 85 psi
Show answer
Answer: D. 80 to 85 psi
Large buses often have warnings that signal at 80 to 85 psi.
From the official CDL manual, section 5.1.11.
16. In controlled braking, you released the brakes to make a larger steering change. When do you re-apply them?
1. A. After you stop steering for ten seconds
2. B. As soon as you can
3. C. Only after the vehicle stops
4. D. Never, coast to a stop
Show answer
Answer: B. As soon as you can
Re-apply the brakes as soon as you can.
From the official CDL manual, section 5.4.3.
17. What does the s-cam do to the brake shoes?
1. A. Pulls them together to grip the outside of the drum
2. B. Squeezes them against a disc held in a caliper
3. C. Pushes a wedge between the ends of the shoes
4. D. Forces them apart against the inside of the drum
Show answer
Answer: D. Forces them apart against the inside of the drum
The s-cam spreads the shoes apart so they press on the inside of the drum.
From the official CDL manual, section 5.1.8.
18. In a dual air brake system, which brakes does one system typically operate?
1. A. Only the trailer brakes
2. B. Only the parking brakes
3. C. The regular brakes on the rear axle or axles
4. D. Only the engine brake
Show answer
Answer: C. The regular brakes on the rear axle or axles
One system typically operates the regular brakes on the rear axle or axles.
From the official CDL manual, section 5.2.
19. How do you test the low air pressure warning signal?
1. A. Run the engine and watch for the signal at fast idle
2. B. Engine off, power on, then fan the brake pedal to lower pressure
3. C. Open all tank drain valves with the engine running
4. D. Pull the parking brake knob out and wait for the signal
Show answer
Answer: B. Engine off, power on, then fan the brake pedal to lower pressure
You shut the engine off, turn the electrical power on, and step on and off the brake pedal to bring pressure down.
From the official CDL manual, section 5.3.3.
20. What is the main danger of a vehicle that has too much brake slack?
1. A. The air compressor will cut out too early
2. B. The spring brakes will come on while driving
3. C. The low air pressure warning will stay on
4. D. It can be very hard to stop
Show answer
Answer: D. It can be very hard to stop
Too much brake slack means the brakes do not apply well, so the vehicle can be very hard to stop.
From the official CDL manual, section 5.3.2.

Georgia CDL Air Brakes questions

What score do you need to pass the Georgia CDL Air Brakes test?

Georgia says you need 80% to pass the Air Brakes test.

Is the Georgia CDL Air Brakes test the same as other states?

The Air Brakes test is built on the same federal knowledge standards in every state, so the topics match the CDL manual. Georgia uses its own handbook: https://dds.georgia.gov/media/12646/download

How much does a CDL permit cost in Georgia?

CLP fee: $10.

What languages is the Georgia CDL knowledge test offered in?

You must be able to read and understand English, and all documents must be in English. The DDS manual says road signs and driving tests are in English only. Which languages the CDL knowledge tests come in is not stated on the official pages.

Sources

https://dds.georgia.gov/media/12646/download
https://dds.georgia.gov/fees-and-terms
https://dds.georgia.gov/georgia-licenses-ids-and-permits/new-license-id-or-permit/how-do-i-cdl-license
Manual sections used in this test: 5.1.11; 5.1.15; 5.1.16; 5.1.4; 5.1.8; 5.2; 5.3.2; 5.3.3; 5.4.2; 5.4.3; 5.4.4; 5.4.7

Air Brakes practice test in nearby states