Free Practice Questions for NE CDL Air Brakes
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7 Job WikiSample NE CDL Air Brakes Practice Questions
Try these sample questions to review concepts for the NE CDL Air Brakes exam. Each question includes a detailed explanation. Start the interactive quiz above for the full 220+ question experience with AI tutoring.
1What is the primary function of the air compressor in a commercial vehicle air brake system?
2At what pressure does the air compressor governor typically cut out (stop pumping air)?
3At what pressure does the air compressor governor typically cut in (start pumping air again)?
4Why must air storage tanks be drained regularly if they are equipped with manual drain valves?
5How often should manual air tank drain valves be operated by the driver?
6What is the purpose of an alcohol evaporator in an air brake system?
7At what pressure is the safety relief valve installed in the first air tank designed to open?
8What happens when the driver presses down on the foot brake pedal (treadle valve)?
9Which foundation brake design is the most common type used on heavy commercial motor vehicles?
10In an S-cam brake assembly, what mechanical action forces the brake shoes against the inside of the brake drum?
About the NE CDL Air Brakes Exam
The Nebraska CDL Air Brakes test is the 25-question knowledge exam used by the Nebraska DMV for drivers seeking to operate commercial vehicles equipped with air brakes, including air-over-hydraulic systems. The exam covers Section 5 of the Nebraska Commercial Driver License Manual: air-brake components, the air compressor and governor, dual systems, spring brakes, low-air warning devices, inspection checks and leakage limits, brake lag, emergency braking, downgrade braking, and L and Z restrictions. Independent practice by OpenExamPrep provides four-option study questions with comprehensive explanations. These practice questions are an English-language MCQ study resource for the knowledge component and do not replace hands-on inspection practice or official knowledge or skills testing.
Exam sponsor: Nebraska Department of Motor Vehicles (DMV). The requirements and fees below concern the certification or admission exam, separate from our free practice resources.
Assessment
A multiple-choice knowledge test administered at Nebraska DMV driver licensing offices covering Section 5 of the Nebraska Commercial Driver License Manual. Removing an existing L or Z restriction also requires a CLP held at least 14 days and vehicle-inspection and road-test segments in a representative air-brake vehicle; an initial CDL or class upgrade may require all three skills segments.
Time Limit
Not published by Nebraska DMV
Passing Score
20 of 25 correct (80%)
Exam / Certification Fees
$15 commercial learner's permit ($10 fee + $5 security fee); $60 for a 5-year CDL ($55 fee + $5 security surcharge); $15 change of class, endorsement, or restriction
Exam sponsor websiteFees, eligibility, and exam policies can change. Confirm them with the exam sponsor before applying or paying.
Official sources
- Nebraska DMV Commercial Driver License · Source checked 2026-10-03
- Nebraska DMV Driver Manuals and Practice Tests · Source checked 2026-10-03
- Nebraska DMV Driver License Examiner Manual (July 2025) · Source checked 2026-10-03
Our practice resources: topics covered
We aim to reflect publicly available exam outlines and topic information in our study resources. Coverage, format, and difficulty may differ from the actual exam, and we cannot guarantee that every detail is accurate or current. Confirm exam requirements, fees, and policies with the official exam sponsor.
Air Brake System Components
Compressor, governor (cut-in around 100 psi, cut-out around 125 psi or the manufacturer's specification), air tanks, drain valves, alcohol evaporators, safety valve (150 psi), foot valve, S-cam drum brakes, and slack adjusters.
Dual Air Brake Systems
Primary and secondary air systems, separate pressure gauges, 100 psi minimum operating pressure, and pressure build-up rate (85-100 psi in 45 seconds).
Emergency and Parking Brake Systems
Spring brakes, automatic valve pop-out between 20 and 45 psi, push-pull dash controls, anti-compounding, and tractor protection valves.
Air Brake Inspection and Testing
The modernized four-part skills-test check (gauge and governor cut-out, applied leakage, warning devices, and spring-brake valve pop-out), plus the manual's static leakage, parking-brake, and service-brake checks. The low-air warning must activate before pressure falls below 55 psi.
Using Air Brakes on the Road
Brake lag distance (0.4 sec / 32 ft at 55 mph), total stopping distance, controlled vs stab braking, brake fade, snub braking on steep grades, and L/Z license restrictions.
Preparing for the NE CDL Air Brakes Exam
What You Need to Know
- Passing score: 20 of 25 correct (80%)
- Assessment: A multiple-choice knowledge test administered at Nebraska DMV driver licensing offices covering Section 5 of the Nebraska Commercial Driver License Manual. Removing an existing L or Z restriction also requires a CLP held at least 14 days and vehicle-inspection and road-test segments in a representative air-brake vehicle; an initial CDL or class upgrade may require all three skills segments.
- Time limit: Not published by Nebraska DMV
- Exam / certification fees: $15 commercial learner's permit ($10 fee + $5 security fee); $60 for a 5-year CDL ($55 fee + $5 security surcharge); $15 change of class, endorsement, or restriction Official sources
Using Our Practice Resources
- Work through all 220 available questions
- Review every answer and explanation
- Track weak areas and revisit them
- Use our AI tutor for tough concepts
NE CDL Air Brakes: Suggested Study Strategy
Frequently Asked Questions
Is the Air Brakes test an endorsement in Nebraska?
No. Air Brakes is a knowledge test and restriction-removal qualification, not an endorsement. Passing the knowledge test avoids the L restriction on a new CLP; removing an L or Z restriction from an existing CDL also requires the applicable skills testing.
What is the difference between the L and Z restrictions on a Nebraska CDL?
An L restriction prohibits operating any commercial motor vehicle equipped with air brakes. A Z restriction indicates the driver tested in a vehicle with air-over-hydraulic brakes rather than full air brakes, prohibiting operation of full air brake CMVs.
What are the acceptable air leakage rates for commercial vehicles?
In the manual's static test, pressure loss must be less than 2 psi per minute for a single vehicle and less than 3 psi per minute for a combination vehicle. In the applied test, the pressure drop must be no more than 3 psi per minute for a single vehicle or 4 psi per minute for a combination vehicle.
At what pressure must the low air pressure warning activate?
The current Nebraska CDL manual says the visible warning must activate before tank pressure falls below 55 psi; a buzzer may also sound. Follow the tested vehicle manufacturer's specification where the modernized skills-test procedure calls for it.
At what pressure do spring brakes pop out automatically?
The tractor protection valve and emergency/parking brake control knobs pop out automatically when air tank pressure drops to between 20 and 45 psi (typically between 20 and 30 psi), causing the spring brakes to apply.
What is brake lag distance?
Air brakes take approximately 0.4 second for air to flow through the lines to the brake chambers after the pedal is pressed. At 55 mph on dry pavement, this adds roughly 32 feet to total stopping distance.
Are these practice questions official Nebraska DMV test items?
No. These are independent practice questions developed by OpenExamPrep based on Section 5 of the Nebraska CDL Driver's Manual. They provide educational study and are not official state examination items.