IL CDL Air Brakes Practice Test 4 2025

If you’re preparing to drive commercial motor vehicles (CMVs) equipped with air brakes (and most of them are), it is necessary that you pass the Illinois CDL Air Brakes Knowledge Test and the Skills Test (in an air brake-equipped vehicle). Without this qualification, your CDL will have the “L” restriction, which limits you to CMVs without air brakes. Since most CMVs (including even large school buses) are air brake-equipped, it is in your best interest to go ahead and pass the tests.

The official Illinois CDL Air Brakes Knowledge Test includes 25 multiple-choice questions. You must answer at least 16 (80%) correctly to pass. If you do not pass, you’ll need to wait at least one business day and pay a retesting fee before another attempt. Our free Illinois CDL Air Brakes Practice Tests help you avoid that delay by mimicking the actual exam, providing immediate feedback with explanations and hints for each question, and avoiding unnecessary fluff often included in less effective guides found elsewhere. Our tests also take into account the common traps, distractors, tricky wording, and double negatives often found on the official exam. With our preparatory tools, you’ll walk into the official exam ready for anything they throw at you.

Our practice tests also feature AI-powered feedback, an interactive Illinois DMV CDL Manual, and a challenge bank that remembers any question you miss. The Challenge Bank then confronts you again with the missed questions until you’ve mastered the material. Once you’ve aced this practice test, try another one from our Illinois series here: https://driving-tests.org/illinois/il-cdl-air-brake-practice-test/.

Illinois features driving landscapes that range from the Chicago metro area and I-55 corridor to long stretches of rural interstates. Grain, machinery, and manufactured goods are carried throughout the state, and air brake-qualified truckers help Illinois’s major industries thrive. These include logistics, agriculture, manufacturing, and construction, all of which rely on air brake-qualified drivers to keep goods moving safely through the Prairie State.

To further expand your opportunities, you should consider earning endorsements like N (Tanker), H (Hazardous Materials), or T (Doubles and Triples). We have Endorsement Practice Tests perfect for preparing you for this task. Try one here: https://driving-tests.org/illinois/il-cdl-hazmat-practice-test/. You might also consider preparing for the CDL Combination Vehicles Knowledge Test, which is part of the requirements for a Class A License. We have practice tests for that as well: https://driving-tests.org/illinois/il-cdl-combination-test/.

With preparation, patience, and a little Illinois grit, you’ll be ready for your knowledge tests and skills test and on the road in no time!