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Kentucky Air Brakes Test

Mountain grades on I-64 and I-75 demand perfect air brake control.

118
Questions
80%
To Pass
30
Minutes

Select Test Mode

DMV Simulator

Timed test with no hints. Simulates the real DMV exam experience.

  • 30 minute time limit
  • No hints or explanations

Learning Mode

Study mode with hints and explanations. Take your time to learn.

  • No time limit
  • Explanations available

About the Kentucky Air Brakes Test

Kentucky's roads aren't flat. You'll haul heavy loads through the Appalachians, down steep grades on I-75, and across winding routes on US-23. Air brakes give you the stopping power you need, but one mistake can be costly. That's why our practice test focuses on the exact skills Kentucky examiners check.

Coal trucks, horse trailers, and logging rigs all depend on air brakes. Kentucky's winter ice and summer thunderstorms make brake fade a real danger. You'll learn to inspect slack adjusters, check air loss rates, and identify brake imbalance before it's too late. Every question comes directly from the Kentucky CDL manual.

We don't waste your time with fluff. You get 25 questions that mirror the state test. Each one includes an explanation so you understand the 'why' behind the answer. Practice until you score 80% or higher – that's the real passing score in Kentucky.

Ready to start? Take the test now. You'll finish in about 30 minutes, and you can retake it as many times as you need. No sign-up, no cost.

What This Test Covers

  • Dual air brake systems – you'll rely on them when hauling coal on KY-80's switchbacks.
  • Air compressor cut-in/cut-out pressures – critical for maintaining brakes on long I-65 descents.
  • Brake lag and stopping distance – longer stops mean more accidents on wet Kentucky roads.
  • Spring brakes and parking brakes – horse trailers need secure parking on steep farm driveways.
  • Check of the low air warning device – a must before climbing any mountain grade in eastern KY.
  • Manual and automatic slack adjusters – proper adjustment keeps your rig legal on Kentucky weigh stations.

Study Tips

Study the Kentucky CDL Air Brakes section, pages 30–45. Don't skip the diagrams – examiners love those. Practice the pre-trip inspection aloud. You'll have to narrate every step for the skills test.

Use the 80/20 rule: focus on the top 6 topics above. They drive most of the test questions. Take our practice test at least three times. Track your wrong answers and review those topics again. Kentucky DMV offices in Lexington and Louisville book up fast – schedule your test early.

Kentucky DMV Information

You take the Air Brakes knowledge test at any Kentucky DMV Regional Office. Walk-ins are limited; make an appointment online at drive.ky.gov. The test fee is $40, payable by cash or card. You'll need your Kentucky driver's license and a completed CDL application.

After passing the written test, you get a CDL permit. You then have 180 days to pass the skills test. Bring your own vehicle with air brakes for the skills exam. Kentucky does not allow testing in rental trucks.

Our practice test matches the official Kentucky question bank. It's updated for 2026 rules. Failing the real test costs you $40 each time, so practice until you're confident.

Frequently Asked Questions

Not if the truck's GVWR is under 26,001 pounds. But any vehicle with air brakes – even a straight truck – requires you to pass the Air Brakes knowledge test. You can't drive a rig with air brakes without this endorsement.

You get 25 questions. You must answer 20 correctly to pass – that's 80%. The test covers air brake system parts, dual systems, brake adjustments, and emergency procedures.

No. You must take it in person at a Kentucky DMV Regional Office. They don't offer remote testing for CDL knowledge exams. Make an appointment to save time.

You can retake it immediately, but you pay the $40 fee each time. Many people fail because they don't know the pre-trip inspection steps. Use our practice test to avoid wasting money.

Yes, if you move to Kentucky, your out-of-state CDL with air brakes endorsement transfers. But you must pass the Kentucky knowledge and skills tests to get a new license. The transfer process takes 30 days.

Related Resources

Download Kentucky CDL Handbook Kentucky DMV Website

Other Kentucky CDL Practice Tests

General Knowledge
Combination Vehicles
Hazmat
Tanker
Passenger
School Bus
Doubles & Triples
Pre-Trip Inspection

Test Details

  • State: Kentucky
  • Test: Air Brakes Test
  • Questions: 118
  • Passing Score: 80%
  • Time Limit: 30 minutes
  • Cost: Free

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Quick Topics

  • Dual air systems & compressor
  • Brake lag & stopping distances
  • Spring brakes & low air warning