OR CDL Air Brakes Practice Test 2026
Original questions by our team Based on 2026 OR CDL Handbook
Air brakes are commonly found on large trucks and buses. They use compressed air to apply pressure to the brake shoes or pads, allowing your vehicle to come to a stop within a safe distance. Your Commercial Driver’s License (CDL) must authorize you to operate vehicles with air brakes, and that’s why you must fully understand how they work.
To operate vehicles equipped with air brakes, you must pass the air brakes knowledge test as well as a skills test in a vehicle equipped with air brakes. Both tests evaluate your knowledge of how this system works, how to inspect your brakes and how to detect brake failure. If you haven’t done so, you will be issued a CDL with a restriction code meaning “No air brake equipped vehicles.”
In Oregon, the written knowledge test is based on the official 2026 CDL manual (https://driving-tests.org/oregon/or-cdl-handbook/). Students can use this handbook to familiarize themselves with what it takes to become a commercial driver, but there are other useful resources available for those who are willing to master this subject.