DE CDL Air Brakes Practice Test 4 2025

Since most large commercial motor vehicles (CMVs) are equipped with air brakes, you’d be shooting yourself in the foot by not removing the air brake restriction from your Commercial Driver’s License (CDL). Chances are, you’re already planning to take the official Delaware DMV CDL Air Brakes Knowledge Test, and you’re here for help preparing. Without passing the Air Brakes Test, your CDL will carry an “L” restriction, making it illegal to operate a vehicle equipped with air brakes. Our Delaware CDL Air Brakes Practice Tests are designed to help you pass your exam on the first attempt.

Our series of Delaware practice tests comes with an interactive handbook, AI-powered feedback, and a challenge bank of questions that remembers what you got wrong and presents real-time feedback on each response. Our experts have eliminated the unnecessary fluff not typically tested and focus on the actual material you need to pass. Our tests follow the same format used by the Delaware DMV. Be sure to check out our other Air Brakes Practice Tests once you’ve mastered this one: https://driving-tests.org/delaware/de-cdl-air-brake-practice-test/.

The official Air Brakes Test consists of two parts. Part One is the written knowledge test, covering the principles of air brake systems, dual air systems, proper inspection, and safe braking techniques. You’ll need at least an 80% score to pass. If you fail, there is a mandatory waiting period and you may face an additional fee. Therefore, be sure to use our practice tests so you can avoid this altogether. There is also a Skills Test that must be passed, during which you must demonstrate a full pre-trip inspection of the air brake system, identify its components, and conduct an air loss and leak test. You must pass a hands-on skills test in a vehicle equipped with air brakes, or you’ll receive the “L” restriction.

Industries across the First State rely on air-brake-qualified drivers, from agriculture and logistics to manufacturing and construction. Major employers like Delaware Constructors, Delaware Motor Transport, and Safer Trucking require drivers certified in air brakes to move freight safely. Charter services such as Beach Bus and Delaware Express depend on qualified drivers, and even school bus operators statewide use air-brake-equipped vehicles.

While you are on a roll, we encourage you to check out our Delaware Endorsement Tests, which add great value and versatility to your CDL. Check out one of our practice tests here: https://driving-tests.org/delaware/de-cdl-hazmat-practice-test/. Additionally, you might want to go ahead and fulfill one of the key requirements for a Class A CDL, which permits you to drive tractor-trailers and other combination vehicles. Check out our Combination Vehicles Practice Test here: https://driving-tests.org/delaware/de-cdl-combination-test/.