Louisiana CDL Air Brakes Practice Test (LA) 2

5 out of 5 (41 votes)
80% Passing score
20 Questions
4 Mistakes allowed
As you prepare to secure your commercial driver's license (CDL) air brakes endorsement, our Louisiana CDL air brake practice test offers a tailored resource that mirrors the distinctive driving environment of Louisiana. Known for its humid climate and frequent heavy rainfall, driving in Louisiana presents unique challenges, particularly when it comes to the functionality and reliability of air brake systems. Understanding these local nuances is critical, and our practice test ensures you are well-versed in handling such conditions. This comprehensive Louisiana air brakes CDL test is designed to boost your knowledge and confidence. With 20 multiple-choice questions that delve into everything from the basic components and operation of air brakes to more complex topics like safety inspections and stopping distance calculations, you'll cover all essential areas. The test specifically emphasizes the importance of dual air brake systems, a critical feature for safety in the event of a system failure. Unlike the timed exams you might encounter elsewhere, the Louisiana permit practice test allows you to take your time with each question, ensuring you fully understand each topic without the pressure of a ticking clock. This approach is especially beneficial in a state like Louisiana, where weather and road conditions can change unexpectedly, requiring drivers to be exceptionally well-prepared. Our Louisiana driving test practice is also regularly updated to reflect the latest driving laws and regulations, guaranteeing that you are studying the most up-to-date material as of 2026. While this test is an excellent tool for review, it's important to note that it should be used in conjunction with a state-certified drivers ed or Entry-Level Driver Training (ELDT) course for the best results. By engaging with our practice test, you're not just memorizing facts; you're integrating them into a practical understanding of safe driving practices essential for Louisiana's unique driving conditions. Prepare to enhance your knowledge and step closer to passing your CDL test with confidence.
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Sample Louisiana Air Brakes Test Questions

Question 1

Which description best fits spring brakes on an air-brake vehicle?

  1. A Brakes operated by hydraulic fluid
  2. B Normal service brakes applied only by compressed air
  3. C Mechanical emergency and parking brakes held off by air pressure
  4. D Brakes installed only on trailers

Correct answer: C – Mechanical emergency and parking brakes held off by air pressure

Louisiana’s CDL manual explains that compressed air holds powerful springs back while the vehicle is moving. When air is released, the springs mechanically apply the brakes. This design is commonly used for emergency and parking functions because the brakes do not depend on stored air pressure to remain applied.

Source: Louisiana Commercial Driver License Manual — § 5.1.14, “Spring Brakes”

Question 2

If a vehicle pulls to one side during a low-speed service-brake test, there may be a brake problem.

  1. A True
  2. B False

Correct answer: A – True

The Louisiana manual directs the driver to build normal air pressure, release the parking brake, move forward slowly at about 5 mph, and apply the service brakes firmly. Pulling to one side, an unusual pedal feel, or delayed stopping can reveal a brake problem. Any abnormal result should be addressed before road operation.

Source: Louisiana Commercial Driver License Manual — § 5.3.3, “Step 7 Final Air Brake Check”

Question 3

On most large air-brake vehicles, spring brakes serve which functions?

  1. A Parking only
  2. B Normal service braking only
  3. C Parking and emergency braking
  4. D Routine speed control on downgrades

Correct answer: C – Parking and emergency braking

Spring brakes are commonly used for both parking and emergency braking. Air pressure normally holds the springs back, and releasing or losing that pressure allows the springs to apply the brakes. They are not the brakes used for ordinary stops during normal driving.

Source: Louisiana Commercial Driver License Manual — § 5.1.14, “Spring Brakes”

Question 4

On a tractor or straight truck, the spring brakes apply automatically if air pressure falls too low.

  1. A True
  2. B False

Correct answer: A – True

Spring brakes are held off by air pressure and apply when that pressure becomes too low. The parking brake valve should close and the spring brakes should engage within the manufacturer’s specified range, generally 20 to 45 psi. Stop safely when the low-air warning activates rather than waiting for automatic application.

Source: Louisiana Commercial Driver License Manual — § 5.3.3, “Step 7 Final Air Brake Check”

Question 5

It is acceptable to leave an air-brake vehicle unattended briefly without applying the parking brakes or chocking the wheels.

  1. A True
  2. B False

Correct answer: B – False

An unattended vehicle must be secured by applying the parking brakes or chocking the wheels. Even a brief absence creates a risk that an unsecured vehicle could roll and cause injury or property damage. The manual also provides special wheel-chocking guidance when brakes are extremely hot or wet in freezing conditions.

Source: Louisiana Commercial Driver License Manual — § 5.4.8, “Parking Brakes”

Question 6

If the ABS malfunctions, the vehicle’s ordinary braking function remains available.

  1. A True
  2. B False

Correct answer: A – True

The Louisiana manual states that regular brakes continue to function when ABS is not working. The vehicle may lose the system’s wheel-lockup protection, but the driver should continue using the brakes normally. The malfunctioning ABS should be serviced soon, and the driver must not treat ABS as permission to drive less carefully.

Source: Louisiana Commercial Driver License Manual — § 5.4.2, “Braking with Antilock Brakes”

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