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Delaware Air Brakes Test

You'll tackle I-95's steep grades around Wilmington and squeeze through tight docks at the Port of Delaware — master your air brakes here.

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 Delaware CDL handbook and FMCSA regulations.

About the Delaware Air Brakes Test

Delaware's highways aren't flat pancakes. I-95 snakes through Wilmington with sharp curves and heavy traffic. Route 1 and 13 carry thousands of trucks daily to the Port of Delaware and the refineries near Delaware City. Air brakes aren't just a requirement — they're your lifeline when a sudden stop means avoiding a pileup on the Delaware Memorial Bridge.

Our practice test covers the air brake system components you'll see on the actual Delaware DMV exam. You'll get questions on the compressor, governor, air tanks, and brake valves. We don't waste your time with fluff. Each question comes straight from the Delaware CDL handbook.

Delaware winters bring wet, icy roads off the Atlantic. You need to know how to manage brake lag and avoid skids. We'll also hit the farms downstate — hauling grain or chickens means steep driveways and gravel lots where air brakes behave differently than pavement.

Take this test right now. No sign-up. No paywall. Just 25 questions that match the real Delaware air brake exam. You'll know if you're ready before you walk into the DMV.

Topics Covered

✓Air brake system components — essential for Delaware's mixed fleet of dump trucks and delivery vans on 13 and 9.
✓Dual air brake systems — critical when a failure on I-495 means one circuit still stops you.
✓Spring brakes and parking brakes — know how to release them when loading at the Port of Wilmington's docks.
✓Brake lag distance — matters more on wet Delaware roads near the coast where stopping distances double.
✓Air gauge operation — Delaware DMV inspectors check you can read those needles at the actual test.
✓Pre-trip inspection steps — fail the air brake pre-trip in Delaware and you fail the whole test.

Study Tips

Study the Delaware CDL handbook's air brake chapter — pages 40-55. The Delaware DMV test pulls directly from that material. Skip the general knowledge sections and focus on air-only questions. We've seen drivers lose points on governor cut-out pressure and low air warning devices.

Practice the pre-trip inspection out loud. Stand next to a truck or use our diagrams. Say each component's name and what it does. Delaware examiners listen for specific terms like 'slack adjuster,' 'pushrod stroke,' and 'low air warning.' They don't care about your theory — they want you to point and say 'this is the compressor, it's belt-driven, no leaks.'

Take our practice test three times. First time, learn. Second, check your speed. Third, get 100%. The real test gives you 50 minutes, but we time you at 30 to build confidence.

Delaware Specific Information

You take the air brakes knowledge test at any Delaware DMV location — Wilmington, Dover, or Georgetown. No appointment needed for the written test. Walk in during business hours, Monday through Friday, 8:30 AM to 4:15 PM. The fee for the CDL knowledge test is $10, but you pay when you apply for your permit. Bring your current driver's license, Social Security card, and proof of Delaware residency.

For the skills test (pre-trip, backing, and road), you must schedule an appointment. Call 302-434-3200 or book online at Delaware DMV's CDL page. The skills test costs $50. You need your own vehicle with air brakes and all lights working. The Delaware DMV doesn't provide trucks.

Here's a local tip: the Dover DMV has the most CDL test slots. Wilmington fills up fast, especially in summer. If you can drive downstate, you'll get a quicker appointment. Bring your air brake system diagram — they let you reference it during the pre-trip inspection.

Frequently Asked Questions

Do I need an air brake endorsement for a Delaware CDL?
Yes, if you drive a vehicle with air brakes or a combination vehicle that requires air brakes. You'll take an additional air brakes knowledge test and an air brake skills test.
How many questions are on the Delaware air brake test?
The Delaware DMV air brake test has 25 questions. You need 20 correct (80%) to pass. The questions are multiple choice.
Can I use the air brake manual during the Delaware DMV test?
No, the knowledge test is closed-book. However, during the pre-trip inspection, you may use a diagram of the air brake system provided by the DMV.
What happens if I fail the air brake test in Delaware?
You can retake it the same day at some locations. Otherwise, wait one business day. There's a $10 retest fee for each attempt after your first try.
Does Delaware require a separate air brake endorsement for a Class B CDL?
Yes. Any commercial vehicle with air brakes — Class A, B, or C — requires the air brake restriction removed by passing the tests. No endorsement code, just a restriction code L if you don't pass.
JM

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

Last verified: August 2026 · FMCSA-compliant content