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North Carolina Air Brakes Test

You'll tackle steep grades on I-40 near Asheville — this test gets you ready for them.

118

Questions

80%

To Pass

Minutes

118 questions · 30 min time limit · 80% to pass

Opens in a practice window — choose your mode inside.

Reviewed by Jack Mahana, CDL Instructor (13+ years)

Last verified: August 2026

All questions sourced from the official North Carolina CDL handbook and FMCSA regulations.

About the North Carolina Air Brakes Test

North Carolina's roads demand air brake mastery. You'll face everything from the flat, humid stretches of I-95 to the twisting mountain descents on US 421. Your brakes need to perform in both hot Piedmont summers and icy winter mornings in the High Country. The CDL Air Brakes test doesn't just check your knowledge — it checks if you can keep a fully-loaded rig safe in these conditions.

Logistics is a big deal here. Warehouses in Greensboro, ports in Wilmington, and furniture trucks leaving Hickory all rely on air brakes. If you're hauling freight through Charlotte's interchanges, a split-second brake response can prevent a disaster. That's why this practice test focuses on real NC scenarios, like stopping on a wet bridge deck near the coast or controlling brake fade on a long downgrade.

You'll see questions on system components, daily inspections, and emergency procedures. We don't waste your time with fluff. Every question ties back to a situation you'll actually encounter on North Carolina highways. Pass this test on your first try, and you'll be one step closer to earning your NC CDL.

Topics Covered

✓Dual air brake systems — crucial for NC's long downhill stretches on US 421

✓Spring brakes and parking brakes — know them before you park on a steep slope in the Piedmont

✓Air brake delay — why you need extra stopping distance on I-40's rainy sections

✓Low pressure warnings — common issue in older trucks running through Charlotte's stop-and-go

✓Brake fade prevention — vital for logging trucks coming out of the Uwharrie Mountains

✓Daily inspection checklist — exactly what NC examiners want to see during the pre-trip

Study Tips

Start with the North Carolina CDL handbook — it's your official guide. Focus on the air brake section and practice the inspection steps out loud. That's what the examiner will ask for during the skills test. You don't need to memorize every psi number, but you'd better know when the low pressure warning light comes on.

Use our practice test to find your weak spots. Take it multiple times. Each attempt shuffles the questions, so you'll see new ones. If you get a question wrong, read the explanation — it's written to match the NC DMV's way of testing. On test day, arrive early, bring your permit, and don't rush. You've got 30 minutes for 25 questions, which is plenty of time.

North Carolina Specific Information

North Carolina DMV offers the Air Brakes knowledge test at all CDL testing locations. You'll find them in Raleigh, Charlotte, Greensboro, Asheville, and Wilmington. You must make an appointment — no walk-ins. Book online at the NCDOT website at least a week in advance. The test costs $35 for the knowledge exam, and you'll need a passing score of 80% to get your Air Brakes endorsement.

Bring your NC driver's license, your CDL learner's permit, and a valid medical card. If you're taking the test in a language other than English, you can request an interpreter, but that takes extra time. Most folks take the computer-based test right at the DMV office. It's all multiple choice. Once you pass, the endorsement goes on your license — no separate card.

Frequently Asked Questions

Do I need a separate air brakes endorsement for a Class B CDL in North Carolina?

Yes, you do. Any vehicle with air brakes — even a Class B straight truck — requires the Air Brakes (L) endorsement. Without it, you can't drive an air-brake-equipped truck legally.

How many questions are on the NC Air Brakes knowledge test?

The official test has 25 questions. You need to answer 20 correctly to pass. That's an 80% score, same as our practice test.

Can I take the Air Brakes test online in North Carolina?

No, you can't. The knowledge test for an endorsement must be taken in person at a DMV office. You'll use a computer terminal there. Our practice test is the best way to prepare before you go.

What happens if I fail the Air Brakes test?

You can retake it the same day if time allows, but you'll have to pay the $35 fee again. If you don't pass, come back another day — no limit on attempts. Just study up first.

Does North Carolina's air brake test cover the same stuff as other states?

It's similar, but NC's test includes state-specific questions about mountain braking and wet road conditions. That's why using a NC-focused practice test like ours gives you an edge.

Reviewed by Jack Mahana, CDL Instructor (13+ years)

Last verified: August 2026 · FMCSA-compliant content