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NC CDL Air Brakes Practice Test 4 2025

Perfect for first-time and renewal CDL/CLP applicants, and those adding endorsements.

You’ve come to the right place for removing the “L” restriction from your CDL. Passing the North Carolina DMV CDL Air Brakes Knowledge Test and the Skills Test in an air brake-equipped vehicle is essential to that process. The “L” restriction prohibits you from operating any commercial motor vehicle equipped with air brakes and creates a serious impediment to accessing a wide range of job opportunities. Removing that restriction is a strong way to add marketability to your CDL. The Air Brakes Knowledge Test includes multiple-choice questions based on the official CDL Manual. You must score at least 80% to pass. If you fail either test (or take the Skills Test in a vehicle not equipped with air brakes), the restriction will remain on your CDL.

Additionally, in North Carolina, if you fail either test, you must wait one day before retesting and pay an added fee. Our North Carolina CDL Air Brakes Practice Tests prepare you to pass on the first try with a variety of study tools that not only grant you familiarity with the exact format of the official test but also contain AI-driven feedback, an interactive CDL Manual, and a Challenge Bank of questions that remembers what you get wrong. It then presents missed questions again and again until you answer them correctly. These proven methods speed learning and increase overall retention. Our practice tests eliminate any unnecessary fluff found in other study guides and make certain you work with tested material, including air brake components, dual-air systems, proper brake inspection, and safe braking techniques. This approach saves you time and mental bandwidth. Once you’ve mastered this practice test, try another from our series: https://driving-tests.org/north-carolina/nc-cdl-air-brake-practice-test/.

From the state’s steep grades to the rolling hills and coastal plains, the Tar Heel State demands dependable braking systems. Air brakes are especially critical on I-40, I-85, I-95, and US-64. The state’s often-severe weather (summer thunderstorms, heavy rains, black ice, and winter snow) further increases the need for properly trained, air brake-qualified drivers.

North Carolina’s economy relies heavily on industries where air-brake-equipped CMVs are standard, including agriculture, energy, freight, logistics, passenger transportation, and manufacturing. Major employers dependent on air brake-qualified drivers include Carolina Biological Supply, Carolina Trailways, Duke Energy, Greyhound Lines, FedEx Freight, Smithfield Foods, Tyson Foods, Volvo Trucks, XPO Logistics, and all North Carolina public school districts.

Consider adding valuable endorsements to your CDL. Our Practice Tests can help: https://driving-tests.org/north-carolina/nc-cdl-hazmat-practice-test/. Also, check out our Combination Vehicles Practice Tests to prepare for the official combination exam: https://driving-tests.org/north-carolina/nc-cdl-combination-test/.

Real exam-style pitfalls you’ll practice:
Common Traps
Distractors
Trick Wording
Double Negatives
NC CDL Air Brakes Practice Test 4 2025
NC commercial driver's license
Based on official NC exam questions
Steven Litvintchouk, M.S., Chief Educational Researcher at Driving-Tests.org

Authored and fact-checked by Steven Litvintchouk, M.S.

Chief Educational Researcher, Driving‑Tests.org (ACES member)
Verified for accuracy November 2025
Methodology & Editorial Policy

9 min to complete
Available in EN and ES

What to expect on the actual NC permit test

25

questions

20

correct answers to pass

80%

passing score

More NC CDL test resources

  1. Air Brakes Test 1
  2. Air Brakes Test 2
  3. Air Brakes Test 4 (you are here)

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