West Virginia CDL Air Brakes Practice Test (WV) 2

5 out of 5 (40 votes)
80% Passing score
20 Questions
4 Mistakes allowed
If you're preparing for the CDL air brake test in WV, you've come to the right place. This West Virginia CDL air brakes practice test is specifically designed to help you pass the air brakes endorsement on your commercial driver's license test. With 20 multiple-choice questions covering key topics such as the operation of air brakes, components, safety inspections, and the all-important stopping distance calculations, you'll get the thorough preparation you need to ace the test. WV's unique landscape, with its winding roads and mountainous terrain, adds an extra layer of importance to mastering your air brakes. The safety and efficiency of your vehicle depend on your understanding of how these brakes work, especially when navigating the steep inclines and declines that are so common here. Whether you're planning to drive a coal truck through the hills or transport goods across the state, having a solid grasp of air brake systems is crucial. This WV learners permit practice test is available to you whenever it fits into your schedule. You can log in online at any time, day or night, to practice at your own pace. This flexibility is especially important for busy West Virginians who may be juggling work, family, and other responsibilities. To get the most out of your preparation, be sure to pair this CDL air brake practice test with additional study materials like the WV Driver's Handbook, state-certified driver education courses, flashcards, and road sign charts. The questions you'll find here are based on the official manual, the same one that the DMV uses to create the actual test, so you can be confident that the material you're studying is relevant and accurate. Passing the WV CDL air brakes practice test requires answering at least 16 out of 20 questions correctly. Take your time, review your answers, and feel confident that you're getting ready for success on the road. Remember, this isn't just about passing a test-it's about ensuring you have the knowledge and skills to drive safely and effectively in West Virginia.
FREE CDL Practice Test App
Pass your West Virginia CDL Air Brake test with the NextDoorDriving app. Real questions and answers—100% free and ad-free.
Download on the App Store

Sample West Virginia Air Brakes Test Questions

Question 1

During the low-air warning test described in West Virginia's CDL manual, the warning signal must activate before tank pressure falls below:

  1. A 80 psi
  2. B 60 psi
  3. C 55 psi
  4. D 40 psi

Correct answer: C – 55 psi

The low-air warning signal must activate before pressure falls below 55 psi in the air tank, or in the lowest-pressure tank of a dual system. This warning should occur before the spring brakes apply, usually between 20 and 45 psi. A signal that does not work may leave the driver unaware of dangerous pressure loss.

Source: West Virginia Commercial Driver’s License Manual — § 5.1.11, “Low Air Pressure Warning”, West Virginia Commercial Driver’s License Manual — § 5.3.3, “Step 7 Final Air Brake Check”

Question 2

What is the main purpose of an alcohol evaporator in an air-brake system?

  1. A To reduce ice formation in valves and other air-system parts
  2. B To raise the air compressor's maximum pressure
  3. C To eliminate the need to drain the air tanks
  4. D To remove alcohol that has collected in the reservoirs

Correct answer: A – To reduce ice formation in valves and other air-system parts

An alcohol evaporator introduces alcohol into the air system to reduce the risk of ice in valves and other components during cold weather. Ice can interfere with brake operation. West Virginia's manual also instructs drivers to check the alcohol container daily in cold weather and continue draining water and oil from tanks unless automatic drains are installed.

Source: West Virginia Commercial Driver’s License Manual — § 5.1.4, “Air Tank Drains”, West Virginia Commercial Driver’s License Manual — § 5.1.5, “Alcohol Evaporator”

Question 3

For a dual air system with minimum-size tanks, pressure should rise from 85 to 100 psi within 45 seconds at operating rpm.

  1. A True
  2. B False

Correct answer: A – True

At operating rpm, a dual air system with minimum-size tanks should build pressure from 85 to 100 psi within 45 seconds. A vehicle with larger tanks may take longer and still meet its manufacturer's specifications. Insufficient pressure buildup can allow air pressure to fall dangerously low during operation, and the problem must be repaired before driving.

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

Question 4

What activates the electrical stop-light switch on a vehicle with air brakes?

  1. A A hand-operated control
  2. B Air pressure
  3. C Hydraulic fluid pressure
  4. D The parking-brake spring

Correct answer: B – Air pressure

The electrical stop-light switch in an air-brake system is operated by air pressure. Applying the air brakes activates the switch, which turns on the vehicle's brake lights. These lights warn following drivers that the commercial vehicle is braking.

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

Question 5

A lightly loaded vehicle is less likely to skid when its spring brakes apply automatically because of low air pressure.

  1. A True
  2. B False

Correct answer: B – False

Lightly loaded vehicles can skid out of control when their spring brakes apply, especially on slippery roads. Drivers should not wait for automatic spring-brake application after a low-air warning. The safer response is to stop and park as soon as possible while enough pressure remains to use the foot brakes in a controlled manner.

Source: West Virginia Commercial Driver’s License Manual — § 5.4.7, “Low Air Pressure”

Question 6

Which device protects service-reservoir pressure if a failure or leak occurs between the reservoir and its air source?

  1. A A one-way check valve
  2. B The air-compressor governor
  3. C The safety relief valve
  4. D The tractor protection valve

Correct answer: A – A one-way check valve

Federal air-brake equipment standards require service reservoir systems to be protected by check valves or equivalent devices. These devices prevent a failure or leak between the reservoir and air source from draining the protected reservoir. The tractor protection valve performs a different function by protecting the towing vehicle from air loss toward a towed vehicle.

Source: 49 CFR § 571.121 S5.1.2.3 — Standard No. 121; Air brake systems

More West Virginia CDL Practice Tests
Other CDL Endorsements