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- Updated for January 2025
- Based on 2025 CO commercial driver's license manual
Free Colorado CDL Air Brakes Test 2025
Planning to drive commercial motor vehicles (CMVs) equipped with air brakes? Our practice materials are just what you need for the written knowledge test. Without passing, your CDL will include the restriction “L,” indicating that you’re not allowed to drive CMVs with air brakes. That’s quite a limitation on your job prospects. (Virtually all semi-trucks and tractor-trailers are equipped with air brakes.) Therefore, preparing for this test is a very wise career choice. In fact, in Colorado, the air brakes qualification is a requirement of most companies due to the commonality of this braking system.
Organizations in Colorado that typically require drivers to have this qualification include J.B. Hunt Transport Services, Schneider National, Inc., Swift Transportation, Werner Enterprises, FedEx and UPS Freight, Old Dominion Freight Line, XPO Logistics, YRC Freight, and Estes Express Lines. Air brakes are more powerful than hydraulic brakes, so they can stop a CMV weighing up to 80,000 pounds. They also provide protective redundancy and safety. Simply put, the “L” restriction makes operating CMVs equipped with air brakes illegal, thus limiting your job prospects. So, let’s take a look at the requirements to remove the “L” and become a winner in the industry.
The official DMV test covers the parts of an air brake system, how to use them effectively, and air-brake inspection procedures. There are two parts to the test: the skills test and the knowledge test. The skills test will require you to physically inspect an air brake system, identify its components, and operate a vehicle equipped with air brakes. This test includes checking air pressure, testing the brakes for leaks, and more. The written test is in a multiple-choice format with questions on the concepts you’ve studied in the state’s CDL manual. You’ll need a score of 80% or higher to pass.
We have taken into careful consideration all that is required for the knowledge test and created Colorado DMV CDL Air Brakes Practice Tests, which mimic the content and format you will face on the official DMV test. With our practice test questions and answers provided in real time, you can learn the material quickly and feel confident as you near the day of your official exam. Once you feel prepared, simply schedule the knowledge test at the DMV, pay any fees, and take the test.
- Perfect for first-time and renewal CDL/CLP applicants, and those adding endorsements
- Triple-checked for accuracy
What you need to know
What to expect on the actual CO DMV exam
questions
correct answers to pass
passing score
List of questions (classic view)
- How would you check your truck's slack adjusters?
- Which of the following can cause brakes to fail or fade?
- Under which conditions are front wheel brakes good?
- When should you drain your air tanks?
- Which of the following should you do before leaving your vehicle unattended?
- Spring brakes are
- How do brakes work on a long, steep downgrade?
- The maximum leakage rates per minute after the initial drop are
- Why must you study air brakes in the state of Colorado?
- Which of the following is true about a dual air brake system?
- Why must air tanks be drained?
- The tractor protection valve
- Which of the following will be true about your brake function if your ABS fails?
- Which of the following is NOT part of the braking process when driving a tractor-trailer combination vehicle with an anti-lock braking system (ABS)?
- What is the best way to test your vehicle's low air pressure warning signal?
- Slack adjusters are
- What is the best way to test if your vehicle's spring brakes come on automatically?
- When should you use the parking brake?
- The purpose of a supply pressure gauge is
- At what measurement is the safety valve USUALLY set to open?
- Which vehicles must have low air pressure warning signals?
- How can you tell if your vehicle is equipped with an anti-lock braking system (ABS)?
- Which of the following is NOT part of the air brake system?
- Which of the following is NOT part of the drum brake?
- An anti-lock braking system (ABS)
- The low air pressure warning signal will come on before the pressure in the air tanks falls below
- A low pressure warning signal is required on
- All vehicles equipped with air brakes have
- With air brake-equipped vehicles, the parking brakes should be used
- The use of air brakes on a downgrade is only a supplement to the
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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:
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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.
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