Nevada CDL Air Brake Test (NV) 2026

4.9 out of 5 (67 votes)
80% Passing score
20 Questions
4 Mistakes allowed
Preparing for your commercial driver's license in Nevada? Our DMV air brake test provides an in-depth assessment environment that mirrors the actual air brakes endorsement test you'll face. This Nevada CDL air brakes practice test is structured with 20 multiple-choice questions that comprehensively cover all elements of air brake systems. From the roles of compressors, reservoirs, and brake chambers to the operational nuances and safety protocols necessary for effective use, this test encapsulates the full spectrum of knowledge needed for CDL certification. Understanding the unique brake lag time in air brakes and its impact on stopping distances is crucial for safe driving practices, and our questions ensure you master these calculations. With a requirement of at least 16 correct answers to pass, this Nevada DMV written test practice challenges you to demonstrate a robust understanding of air brakes. Designed to complement traditional drivers education courses, the Nevada permit practice test doesn't replace state-certified training but enhances it. By integrating questions that mimic those you will encounter on the real test, both in style and substance, it aids in building familiarity with the test format and types of questions expected. This is especially beneficial for those who learn best visually, as many of the questions include images and diagrams that aid comprehension and retention of information. Whether you are brushing up on your knowledge or testing your readiness for the official test, our Nevada DMV air brake test is an excellent tool for ensuring you're fully prepared for your CDL air brakes endorsement.
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Sample Nevada Air Brakes Test Questions

Question 1

During the standard air-brake inspection described in Nevada’s CDL manual, the low-air warning must activate before pressure falls below:

  1. A 45 psi
  2. B 50 psi
  3. C 55 psi
  4. D 80 psi

Correct answer: C – 55 psi

The low-air warning must activate before pressure drops below 55 psi in the tank, or in the lowest-pressure tank of a dual system. If the warning does not operate, the driver may not know that usable brake pressure is being lost. Some vehicles may have a manufacturer-specified warning point above this minimum.

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

Question 2

A modern air-brake system consists of service, parking, and emergency braking systems.

  1. A True
  2. B False

Correct answer: A – True

Air brakes are described as three braking systems: service, parking, and emergency. The service system operates when the brake pedal is used during normal driving. The parking system applies the parking brakes, while the emergency system uses portions of the service and parking systems to stop the vehicle following a brake-system failure.

Source: Nevada Commercial Driver’s License Manual — Section 5, “Air Brakes”

Question 3

With the engine off and service brakes fully applied, what is the maximum acceptable air-pressure loss for a single vehicle?

  1. A 3 psi in one minute
  2. B 2 psi in 45 seconds
  3. C 1 psi in one minute
  4. D 1 psi in 30 seconds

Correct answer: A – 3 psi in one minute

For the applied-brake leakage test, fully apply the foot brake and hold it for one minute after the pressure stabilizes. A single vehicle must not lose more than 3 psi during that minute. The corresponding maximum for a combination vehicle is 4 psi in one minute; excessive loss requires repair before driving.

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

Question 4

What activates the electrical stop-light switch in an air-brake system?

  1. A A hand-operated control
  2. B Air pressure
  3. C Hydraulic pressure
  4. D Spring pressure

Correct answer: B – Air pressure

The air-brake system uses an electrical switch operated by air pressure. When the driver applies the air brakes, pressure activates the switch and turns on the brake lights. This alerts following drivers that the commercial vehicle is slowing or stopping.

Source: Nevada Commercial Driver’s License Manual — § 5.1.12, “Stop Light Switch”

Question 5

A slack adjuster that moves more than about one inch where the push rod attaches probably needs adjustment or repair.

  1. A True
  2. B False

Correct answer: A – True

With the vehicle secured and parking brakes released, pull firmly on each reachable slack adjuster. Movement exceeding about one inch at the push-rod attachment indicates that adjustment may be needed. Automatic slack adjusters must still be inspected, and an out-of-adjustment automatic unit should be professionally repaired rather than routinely adjusted by hand.

Source: Nevada Commercial Driver’s License Manual — § 5.3.2, “During Step 5 Walk-around Inspection”

Question 6

Why must air-brake storage tanks be drained?

  1. A To complete the service-brake test
  2. B To measure the system’s leakage rate
  3. C To remove accumulated water and compressor oil
  4. D To activate the low-air warning

Correct answer: C – To remove accumulated water and compressor oil

Compressed air commonly contains water and compressor oil that collect in the storage tanks. These contaminants can harm the brake system, and water can freeze in cold conditions and interfere with brake operation. Manually drained tanks should be emptied completely at the end of each day of driving; automatic drains should also be checked.

Source: Nevada Commercial Driver’s License Manual — § 5.1.4, “Air Tank Drains”

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