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View All Plans- Updated for May 2025
- Based on 2025 ND commercial driver's license manual
Free North Dakota CDL Air Brakes Test 2025
For a sure-fire method of passing your North Dakota DOT CDL Air Brakes Knowledge Test, our CDL Air Brakes Practice Tests are the key. If you don’t pass the Knowledge Test, your CDL will include the restriction “L,” preventing you from operating commercial motor vehicles (CMVs) with air brakes. Securing a CDL without an air brake restriction is vital for expanded job opportunities because most semi-trucks, tractor-trailers, and commercial buses rely on air brakes. Failing the air brakes test results in a one-day waiting period and a fee should you decide to retest. Use our North Dakota DOT CDL Air Brakes Practice Tests to pass on the first attempt.
Due to North Dakota’s diverse terrain, from high winds that cross the mostly flat terrain to the rolling hills in the Badlands, air brakes are necessary for large CMVs. North Dakota’s severe winters bring a lot of snow and ice that require reliable braking systems. Key transportation routes include I-94 (a major east-west route connecting Fargo, Bismarck, and Dickinson), I-29 (running north-south, linking the state to Canada and South Dakota), US-2 (serving the northern part of the state and its oil transportation), and US-83 (running north-south through Bismarck, critical for regional distribution). The restriction “L” would severely limit your job opportunities.
The Peace Garden State relies on drivers with the air brake qualification in industries such as agriculture, energy, and manufacturing. Major companies requiring this qualification include Hess Corporation and Marathon Oil in the energy sector and CHS Inc. and Bobcat in the agriculture and manufacturing industries. Harlow’s Bus and Truck Sales (Bismarck) and Jefferson Lines (Fargo) are charter bus companies requiring air brake-qualified drivers. Additionally, thousands of North Dakota full-size school buses require air brakes, creating numerous employment opportunities for drivers qualified to operate air brakes. Removing the “L” restriction is essential to these jobs.
Our CDL Air Brakes Practice Tests cover everything needed for the official DOT Air Brakes Knowledge Test. This material will also help you practice for your skills test. The written Air Brakes knowledge test features multiple-choice questions based on the state’s CDL manual (North Dakota CDL Handbook 2025) and requires a score of at least 80% to pass.
Our Practice Tests mimic the official knowledge test and offer instant feedback on all responses. This approach has been proven to speed learning and ensures you pass the test.
- Perfect for first-time and renewal CDL/CLP applicants, and those adding endorsements
- Triple-checked for accuracy
What you need to know

What to expect on the actual ND DOT exam
questions
correct answers to pass
passing score
List of questions (classic view)
- How can you tell if your vehicle is equipped with an antilock braking system (ABS)?
- The purpose of a supply pressure gauge is
- Slack adjusters are
- Which of the following are true about a dual air brake system?
- Spring brakes are
- The tractor protection valve
- When should you use the parking brake?
- Which of the following is NOT part of the braking process when you're driving a tractor-trailer combination vehicle with an antilock braking system (ABS)?
- Which of the following is NOT part of the drum brake?
- An antilock braking system (ABS)
- At what measurement is the safety valve USUALLY set to open?
- Which vehicles must have low air pressure warning signals?
- After the initial drop, the maximum acceptable leakage rates per minute are
- Which of the following will be true about your brake function if your antilock braking system (ABS) fails?
- How would you check your truck's slack adjusters?
- Which of the following should you do before leaving your vehicle unattended?
- When should you drain your air tanks?
- Under which conditions are front wheel brakes good?
- How do brakes work on a long, steep downgrade?
- Which of the following can cause brakes to fade or fail?
- What is the best way to test if your vehicle's spring brakes come on automatically?
- Why must you pass a knowledge test on air brakes?
- What is the best way to test your vehicle's low air pressure warning signal?
- Which of the following is NOT part of the air brake system?
- If the air tanks are not drained,
- The low air pressure warning signal will come on before the pressure in the air tanks falls below
- A low pressure warning signal is required on
- All vehicles equipped with air brakes have
- With air brake-equipped vehicles, the parking brakes should be used
- The use of air brakes on a downgrade is only a supplement to the
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