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Maryland Air Brakes Test

You’ll navigate I-95 through Baltimore and the Capital Beltway — your air brakes better work right every time.

118
Questions
80%
To Pass
30
Minutes

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

Opens in a practice window — choose your mode inside.

JM

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

Last verified: August 2026

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

About the Maryland Air Brakes Test

Maryland’s roads demand a lot from your air brake system. You’ll haul freight down I-95 through Baltimore’s tunnels and across the Bay Bridge. Heavy traffic, sudden stops, and steep grades near Frederick test your skills daily. Our practice test mirrors the real Maryland CDL air brakes exam.

Winter weather adds another layer. Ice and snow hit the I-70 corridor and Western Maryland hard. You need to know brake lag, emergency stopping, and how moisture freezes in air lines. These questions prepare you for those conditions.

Maryland’s ports and farms mean commercial trucks carry everything from shipping containers to chicken feed. Each load changes your braking distance. We cover inspection procedures, the spring brake system, and low-air warning devices — all critical for local routes.

This free test helps you find weak spots before your DMV appointment. Answer 25 questions, review the explanations, and walk in confident. No sign‑up required.

Topics Covered

✓Air brake system components – why you’ll inspect them daily on Maryland’s weight stations near I-95
✓Dual air brake systems – crucial for redundancy on long downhills like US-40 in Garrett County
✓Brake lag distance – matters more when you’re merging onto the Beltway at rush hour
✓Emergency braking techniques – needed for sudden deer crossings on rural MD highways
✓Low air pressure warnings – MD inspectors check this rigorously during the pre-trip
✓Spring brake operation – know how to release them after a mandatory rest stop

Study Tips

Practice with our test until you score 90% or better. The real Maryland CDL air brakes exam has 25 questions, and you need 80% to pass. Focus on the parts that tripped you up — review the Maryland CDL Handbook sections 5.1 through 5.4.

At the DMV, you’ll also do a pre-trip inspection. Practice checking the air governor cut‑out pressure (100–125 psi) and listening for air leaks. If you can’t find a typical Maryland vehicle, watch the MVA’s official video. Study in short bursts, and take our test between shifts.

Maryland Specific Information

You take the Air Brakes knowledge test at any Maryland DMV office that handles CDLs. Popular locations include the Glen Burnie hub, Waldorf, and Frederick. No appointment is needed for knowledge tests — walk‑ins accepted during business hours. Bring your learner’s permit and pay the $15 endorsement fee (cash or card).

After you pass, you’ll get the L endorsement on your permit. Then you must pass a skills test in a vehicle with air brakes. Schedule that online through the Maryland MVA. Same fee applies. If you fail the knowledge test, you can retake it the same day after a 1‑hour wait. No extra fee for the retake.

Frequently Asked Questions

Do I need a separate air brakes endorsement for my Maryland CDL?
Yes. If your vehicle has air brakes, you need the L endorsement. The Maryland DMV tests you on air brake knowledge during your written exam.
Can I take the air brakes test online in Maryland?
No. The knowledge test is only available at DMV offices. Use our practice test to prepare, then visit a local office.
What happens if I fail the Maryland air brakes test?
You can retake it the same day after a 1‑hour wait. No charge for the retake. Study more and try again.
How long is the air brakes endorsement valid on my Maryland CDL?
It’s valid for the same period as your CDL — usually 5 years. You renew it during your regular license renewal.
Do I need to show a vehicle with air brakes for the skills test?
Yes. If you want the L endorsement, your test vehicle must have operating air brakes. The inspector will check them during the pre‑trip.
JM

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

Last verified: August 2026 · FMCSA-compliant content