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The air brakes endorsement applies to applicants who wish to drive a vehicle with air brakes in Class A, B, or C CDL. To drive a vehicle with air brakes, you must pass the air brake component of the North Carolina CDL knowledge test. The NC CDL air brakes test consists of 25 questions, and you'll need at least 20 correct answers to pass (80%). The test covers the information found in the air brakes section of the North Carolina CDL Manual. Take this NC CDL practice test now to prepare for the actual air brakes test!
1.
Before leaving your vehicle unattended, you should:
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Chock the wheels.
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Apply the parking brake.
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Remove the keys.
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All of the above.
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2.
Why must air tanks be drained?
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To keep from fouling the air compressor oil.
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Water and
oil reduce the air pressure.
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The low boiling point of water reduces braking power.
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Water can freeze in cold weather and cause brake failure.
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3.
Which of the following is not part of the air brake system?
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Air compressor
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Alcohol evaporator
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Air storage tanks
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Air filter
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4.
Some air brake systems have an alcohol evaporator to:
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prevent ice from forming in the brake system.
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reduce the stopping power of the vehicle.
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reduce the danger of slipping.
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force the brake shoes away from one another.
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5.
Which of the following is NOT part of the drum brake?
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Brake drum
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Return spring
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Safety valve
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Axle
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6.
If your vehicle is equipped with air brakes, loss of air pressure in the
emergency line causes:
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the trailer emergency brakes to come on.
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the speed of your vehicle to increase.
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the trailer spring brakes to come on.
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All of the above.
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7.
The stop light switch:
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turns on the brake lights when you put on the air brakes.
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should be used to fend off tailgaters.
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warns you when the air supply pressure drops below 55 psi.
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tells you when you need to use your parking brake instead of the service brake.
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8.
When going down a steep downgrade, you should:
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use the parking brake.
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avoid braking and rely on engine braking.
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use a low gear, and a proper braking technique.
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use escape ramps whenever possible.
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9.
To check slack adjusters on S-cam brakes, you should:
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use gloves and pull hard on each slack adjuster you can reach.
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press the brake pedal and listen for any strange noises.
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check that the spring brakes come on automatically.
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All of the above.
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10.
An ABS system:
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keep your wheels from locking when you brake hard.
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gives you more control over the vehicle during braking.
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helps you avoid skids caused by over braking.
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All of the above.
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Frequently Asked Questions
Teens between 15 and 18 years old must adhere to the age requirements of the Graduated Driver License law to obtain a class C driver license:
- Limited learner’s permit ? You must be at least 15 and less than 18 and have completed a driver education course.
- Limited provisional license ? You must be at least 16 and less than 18 and have held the limited learner’s permit for 12 months without any traffic violations in the previous 6 months.
- Full provisional license ? You must be at least 16 and less than 18 and have held the limited provisional license for at least 6 months without any traffic violations.
If you are 18 years old, you may apply for a learner permit and obtain a full driver's license after completing the knowledge, vision, and driving tests.
Make an appointment online for the DMV written test by selecting the nearest driver license office. You can choose dates and times based on your preferences and the available options at different North Carolina DMV locations.
First time applicant must bring the following documents:
- One proof of identity and age.
- One proof of a Social Security number.
- One proof of North Carolina residency (two for an NC REAL ID).
- One proof of legal presence (for applicants not born in the U.S.).
If you're under 18, you also need to show:
- Driving Eligibility Certificate and a Driver's Education Certificate.
- Proof of high school graduation or a GED.
You can check all the required documents here.
North Carolina provides DMV written tests in various languages. Additionally, oral tests can be requested if needed. Although language options are provided, it is advisable to have a basic understanding of English since road signs are always in English.
The best way to prepare for the DMV written test is by reading the North Carolina Driver’s Handbook, which contains information about road signs, safe driving practices, and road rules. After studying the manual, verify your preparation with our free practice tests!
For individuals under 18, it’s not permitted to use a cell phone while driving unless in emergency situations.
Other restrictions apply. If you have a limited learner’s permit:
- You can drive only with a supervising driver (parent/legal guardian) who has held a license for at least five years.
- For the first six months, you may drive only between 5:00 a.m. and 9:00 p.m.; afterward, you may drive anytime under supervision.
- Both your passengers and you must wear seat belts or child safety restraints.
If you have a limited provisional license:
- You can drive alone from 5:00 a.m. to 9:00 p.m.
- You may drive anytime under the supervision of a parent/guardian/driver approved by your parent/guardian who has held a license for at least five years. It's possible for you to drive alone anytime for work, volunteer fire, or emergency medical service activities.
- Both your passengers and you must wear seat belts or child safety restraints.
- You can transport no more than one passenger under 21, except for siblings.
A limited learner's permit is valid until your 18th birthday. If you need to renew it, visit a North Carolina DMV office.
If you don't pass your DMV written test, you can retake it after seven calendar days. Use this week to prepare for your next attempt by reviewing the sections of the manual that you didn't study accurately. If you find the exam difficult, sign up for DMV Premium, which offers numerous resources and practice tests to improve your preparation.