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Free Louisiana CDL Air Brakes Test 2025

Part of mandatory Entry-Level Driver Training Course Based on 2025 LA commercial driver's license manualAvailable in EN, ES
30questions
6mistakes allowed
80%passing score

Failure to pass the Louisiana OMV CDL Air Brakes Knowledge Test means that your CDL will include the restriction “L.” By preventing you from operating commercial motor vehicles (CMVs) with air brakes, this restriction will negatively affect your job prospects. A one-day waiting period and fee are implemented should you decide to retake the test after failing it. Our Louisiana OMV CDL Air Brakes Practice Tests provide the tools to pass on the first attempt.

From the state’s flat coastal plains, the wetlands, and the Mississippi River Delta to the flood-prone areas affected by annual rainstorms, hurricanes, and icy winters, the reliability provided by air brakes is sought after for heavy freight transports. Key transportation routes that require air brake-qualified drivers include I-10 (connecting Louisiana to Texas and Florida), I-20 (an east-west route linking Louisiana to Georgia), I-49 (running north-south between Shreveport and Lafayette), and US-61 (linking Louisiana to Mississippi and other states). Since most semi-trucks, tractor-trailers, and commercial buses rely on air brakes for safe navigation, removing the air brake restriction from your CDL is crucial for expanded job opportunities.

The Pelican State relies on drivers with the air brake qualification in key industries, including oil and gas, agriculture, petrochemicals, and tourism. Companies requiring air brake-qualified drivers include ExxonMobil and Chevron in the oil and gas industry and Pilgrim’s Pride and JBS USA in the agriculture sector. FedEx Freight, XPO Logistics, and Schneider National are major companies in the logistics and freight sector that require air brake-qualified drivers, as do Dow Chemical and Honeywell in the manufacturing sector. Greyhound Lines and Lafayette Bus Lines are major companies in the charter bus industry. Finally, hundreds of drivers are employed by Louisiana’s school districts to drive their air brake-equipped full-size school buses. The “L” restriction makes these opportunities unattainable.

The multiple-choice Air Brakes knowledge test is based on the official state CDL manual (Louisiana CDL Handbook 2025) and requires a minimum passing score of 80%. Our CDL Air Brakes Practice Tests thoroughly prepare you for the official OMV Air Brakes Knowledge Test. Additionally, the information you learn will help prepare you for your skills test.

You’ll receive instant feedback on all your Practice Test responses, and our tests mimic the official knowledge test. This method speeds learning and ensures you pass the knowledge test!

Perfect for

  • First-time LA CDL and CLP applicants
  • CDL holders adding endorsements
  • LA CDL renewal applicants
LA commercial driver's license

What to expect on the actual exam

How many questions25
How many correct answers to pass20
Passing score80%
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List of questions (classic view)

  1. Which of the following should you do before leaving your vehicle unattended?
  2. When should you use the parking brakes?
  3. How do brakes work on a long, steep downgrade?
  4. Under which conditions are front-wheel brakes good?
  5. The purpose of a supply pressure gauge is
  6. Which of the following are true about a dual air brake system?
  7. Which of the following can cause brakes to fade or fail?
  8. When should you drain your air tanks?
  9. Spring brakes are
  10. Slack adjusters are
  11. At what measurement is the safety valve USUALLY set to open?
  12. How do you check your truck's slack adjusters?
  13. 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)?
  14. Which of the following is NOT part of the drum brake?
  15. An anti-lock braking system (ABS)
  16. Which vehicles must have low air pressure warning signals?
  17. Which of the following will be true about your brake function if your anti-lock braking system (ABS) fails?
  18. What is the best way to test if your vehicle's spring brakes come on automatically?
  19. If the air tanks are not drained,
  20. How can you tell if your vehicle is equipped with an anti-lock braking system (ABS)?
  21. After the initial drop, the maximum acceptable leakage rates per minute are
  22. Which of the following is NOT part of the air brake system?
  23. What is the best way to test your vehicle's low air pressure warning signal?
  24. Why must you pass a knowledge test on air brakes?
  25. The tractor protection valve
  26. The low air pressure warning signal will come on before the pressure in the air tanks falls below
  27. A low pressure warning signal is required on
  28. All vehicles equipped with air brakes have
  29. With air brake-equipped vehicles, the parking brakes should be used
  30. The use of air brakes on a downgrade is only a supplement to the

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