Nebraska CDL Air Brakes Practice Test (NE) 2

5 out of 5 (36 votes)
80% Passing score
20 Questions
4 Mistakes allowed
Welcome to the Nebraska CDL air brakes practice test, where you can hone your skills and knowledge in preparation for the CDL air brake endorsement. This Nebraska DMV air brake test is specifically designed to cover essential topics such as components, operation, safety inspections, and stopping distance calculations, providing a thorough understanding of the air brake systems that are crucial for safe driving. With 20 multiple-choice questions, this CDL air brake practice test mimics the format of the actual written test, helping you become familiar with the style and types of questions you will encounter. One of the standout features of the Nebraska CDL air brakes practice test is its emphasis on dual air brake systems. These systems are vital for enhancing safety by ensuring a backup in case one system fails. Understanding how these systems work is critical for anyone planning to drive commercial vehicles in Nebraska, where the diverse landscape-from open plains to bustling urban areas-demands careful and informed driving. Accessibility is a key advantage of the Nebraska DMV air brake test. Available online around the clock, you can access it from your desktop, mobile, or tablet device. This means you can fit your learners permit test prep into your schedule whenever it's convenient, making it easier to balance other responsibilities you might have. Whether you're at home in Omaha or on a break in Lincoln, this Nebraska practice driving test is always at your fingertips. The ease of scheduling this practice test offers significant flexibility for those busy with work or family commitments. Instead of being tied to specific class times, you can complete the Nebraska CDL air brakes practice test anytime, ensuring you can study when you're most focused and ready to learn. This flexibility is particularly beneficial given Nebraska's varied weather conditions, which can affect driving safety and test preparation. Whether you're preparing during a hot summer or a snowy winter, the online format ensures you have uninterrupted access to the resources you need. By passing this practice test, you'll be well on your way to achieving your commercial driver's license with an air brakes endorsement, ready to tackle Nebraska's roads with confidence and competence.
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Sample Nebraska Air Brakes Test Questions

Question 1

When checking free play in reachable S-cam brake slack adjusters, which procedure is correct?

  1. A Keep the parking brakes applied and watch the adjusters while pressing the brake pedal
  2. B Drain all air pressure and adjust each push rod with a wrench
  3. C Park level, chock the wheels, release the parking brakes, and pull firmly on each adjuster
  4. D Apply the emergency brakes and gently move the vehicle

Correct answer: C – Park level, chock the wheels, release the parking brakes, and pull firmly on each adjuster

Park on level ground and chock the wheels before releasing the parking brakes. Wearing gloves, pull firmly on each reachable slack adjuster. Movement of more than about one inch where the push rod attaches indicates that the brake probably needs adjustment. Excessive slack can make the vehicle difficult to stop.

Source: Commercial Driver’s License Manual (Supplement to the Nebraska Driver’s Manual) — § 5.3.2, “During Step 5 Walk-around Inspection”

Question 2

A low-air-pressure warning requires you to stop and safely park as soon as possible.

  1. A TRUE
  2. B FALSE

Correct answer: A – TRUE

The Nebraska manual instructs drivers to stop and safely park as soon as the low-air warning activates. The warning may indicate a system leak, and controlled braking is possible only while sufficient air remains. Spring brakes can apply when pressure drops into the 20–45 psi range, potentially causing a skid or uncontrolled stop.

Source: Commercial Driver’s License Manual (Supplement to the Nebraska Driver’s Manual) — § 5.4.7, “Low Air Pressure”

Question 3

During an air-brake check, how do you verify that the spring brakes apply automatically?

  1. A Release the parking brake and repeatedly apply and release the foot brake
  2. B Apply the parking brake and repeatedly press the foot brake
  3. C Drive at least 20 mph and make a hard stop
  4. D Repeatedly apply and release only the parking brake

Correct answer: A – Release the parking brake and repeatedly apply and release the foot brake

With the engine off and the parking brake released, repeatedly apply and release the foot brake to reduce tank pressure. At the manufacturer’s specified pressure, normally within 20–45 psi, the parking-brake valve should pop out. On a tractor-trailer, the tractor-protection control should also close. This causes the spring brakes to apply.

Source: Commercial Driver’s License Manual (Supplement to the Nebraska Driver’s Manual) — § 5.3, “Check That Spring Brakes Come On Automatically”

Question 4

When should air tanks with manual drain valves be emptied?

  1. A At the end of each week
  2. B At the beginning of each week
  3. C At the beginning of each driving day
  4. D At the end of each driving day

Correct answer: D – At the end of each driving day

The Nebraska manual requires manually drained air tanks to be emptied completely at the end of each day of driving. Compressed air carries moisture and compressor oil that collect in the tanks. Water can freeze and interfere with brake operation. Tanks equipped with automatic drains operate differently, although some also allow manual draining.

Source: Commercial Driver’s License Manual (Supplement to the Nebraska Driver’s Manual) — § 5.1.4, “Air Tank Drains”

Question 5

Under normal parking conditions, may you leave a commercial vehicle unattended briefly without applying the parking brakes or chocking the wheels?

  1. A TRUE
  2. B FALSE

Correct answer: B – FALSE

A commercial vehicle must not be left unattended without being secured by the parking brakes or wheel chocks. The vehicle can roll and cause injury or property damage even when the driver plans to be away only briefly. Parking brakes should normally be used whenever the vehicle is parked, subject to the manual’s precautions for extremely hot or frozen brakes.

Source: Commercial Driver’s License Manual (Supplement to the Nebraska Driver’s Manual) — § 5.4.8, “Parking Brakes”

Question 6

At approximately what pressure is an air-brake safety relief valve normally set to open?

  1. A 40 psi
  2. B 80 psi
  3. C 120 psi
  4. D 150 psi

Correct answer: D – 150 psi

The safety relief valve protects the air tank and the rest of the braking system against excessive pressure. It is normally set to open at approximately 150 psi. Air releasing from this valve indicates a system fault rather than normal operation, and the problem should be repaired by a mechanic.

Source: Commercial Driver’s License Manual (Supplement to the Nebraska Driver’s Manual) — § 5.1.6, “Safety Valve”

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