Free Missouri CDL Air Brakes Test 2025

Perfect for first-time and renewal CDL/CLP applicants, and those adding endorsements
Based on 2025 MO commercial driver's license manual
Triple-checked for accuracy
Updated for March 2025

Securing a CDL without an air brake restriction is vital for expanded job opportunities in Missouri because most semi-trucks, tractor-trailers, and large buses rely on air brakes for safe navigation. Failure to pass the Missouri DOR CDL Air Brakes Knowledge Test results in your CDL including the restriction “L,” which will prevent you from operating commercial motor vehicles (CMVs) with air brakes. Failing the air brakes test in Missouri also results in a one-day waiting period and a retest fee should you decide to retake the test. Our Missouri DOR CDL Air Brakes Practice Tests help you pass your knowledge exam on the first attempt.

From the rolling hills, river valleys, and flat plains to the steep grades and winding roads of the Ozark Mountains, Missouri’s diverse terrain demands the mastery of air brakes for hauling heavy loads in these regions. Key transportation routes include I-70 (major east-west route from St. Louis to Kansas City), I-44 (passes through the Ozarks with steep grades), Route 60 (east-west corridor with hilly terrain), and I-55 (follows the Mississippi River). Given these challenges (and the opportunities they provide), the restriction “L” would severely limit your job prospects.

The Show Me State relies on drivers with the air brake qualification in key industries, including agriculture, manufacturing and freight (Boeing and Ford), and tourism (Branson and Lake of the Ozarks). Major companies requiring this qualification include Hogan Transportation (St. Louis), Prime Inc. (Springfield), and YRC Freight (Kansas City) in the logistics sector, as well as Jefferson Lines (Kansas City and St. Louis) and Metro Transit (St. Louis) in the charter bus and public transit industry. Missouri’s school districts also employ thousands of air brake-qualified drivers for their full-size school buses. The “L” restriction makes all these opportunities unattainable.

Our CDL Air Brakes Practice Tests cover all key information for the official DOR Air Brakes Knowledge Test. The information you learn will also be useful as you practice inspecting and operating CMVs to pass your skills test. Featuring multiple-choice questions that are based on the state’s CDL manual (Missouri CDL Handbook 2025), the written Air Brakes knowledge test requires a score of at least 80% to pass.

Our practice tests also provide real-time feedback on all responses. This scientifically proven approach helps you learn faster and ensures you pass the test.

9 min to complete

Available in EN and ES

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What to expect on the actual MO DOR exam

questions

correct answers to pass

80%

passing score

Helpful links

MO DMV website

Official Missouri CDL manual (2025)

More MO DOR Written Exam Resources

MO CDL Air Brakes Test (you are here)

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Our commitment to accuracy and quality in our practice tests

Explore our rigorous, multi-tiered verification process that ensures each question mirrors the official manual for unparalleled accuracy.

Written by Andrei Zakhareuski Updated over a week ago

At Driving-Tests.org, we understand the importance of reliable and accurate practice tests to help you prepare for your DMV exam. That's why we've developed a meticulous process to create and continually update our practice questions, ensuring they reflect the most current driving laws and regulations.

Here's an inside look at how we maintain the highest quality in our practice tests.

Content Creation and Verification Process

Alignment with Official Manuals:
Every question we develop is based on the most recent version of each state's official driving manual. Our team regularly monitors each state DMV's website for the latest updates to ensure our practice tests are always aligned with the most current information.
Community Feedback Integration:
We leverage feedback from our vast community of users to understand which topics are most frequently tested. This helps us focus on the areas that are most relevant and beneficial for your preparation.
Expert Content Creation:
Our in-house editor, Steven, who has extensive experience in driver education, crafts each question with precision. He conducts a thorough review of each question against the official manuals to ensure accuracy.
Rigorous Review Process:
Once Steven has finalized a set of questions, our team conducts a joint review session. This second level of scrutiny involves content accuracy, proofreading, and fact-checking to eliminate any errors.
User Feedback Mechanism:
After a question goes live on our site, we keep the lines of communication open. Each question features a feedback button, inviting users to report any issues or errors. This continuous feedback loop allows us to address and rectify any concerns promptly.
Responsive Updates:
In line with our commitment to accuracy, we quickly update our practice questions to reflect any changes in the DMV manuals. Additionally, we update the free electronic copy of the state's driver's license manuals on our site, typically within a few days after the DMV publishes them.

Our thorough quality control process ensures that you have access to practice tests that are as accurate and up-to-date as possible. We believe in the power of well-prepared drivers and are dedicated to providing you with the best study tools to help you succeed on your DMV exam.

FREE Missouri CDL Air Brakes Test

Our practice tests also provide real-time feedback on all responses. This scientifically proven approach helps you learn faster and ensures you pass the test.

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