AIR BRAKES CDL PRACTICE TEST - NORTH CAROLINA

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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. Dual tires:
should not come in contact with each other.
are dangerous.
should come in contact with each other whenever possible.
should always come in contact with each other.
2. The ABS malfunction lamp on the instrument panel is:
Blue
Red
Orange
Yellow
3. If a vehicle is equipped with ABS, when you start the engine:
the spring brakes will come on.
the wheels will lock up.
the trailer emergency brakes will come on.
the ABS indicator light on the dash should come on and then turn off.
4. The supply pressure gauges tell you how much air pressure:
is going to the brake chambers.
you are applying to the brakes.
is in the air brakes.
is in the air tanks.
5. During a trip you should check:
temperature gauges.
pressure gauges.
mirrors.
All of the above.
6. The application pressure gauge:
shows how much air pressure is being applied to the brakes.
stops the compressor from pumping air.
protects the tank and the rest of the system from too much pressure.
tells you how much pressure is in the air tanks.
7. The s-cam forces the brake shoes away from one another and presses them against the inside of the brake drum. It is called the s-cam because:
"S" stands for "Shoes".
it is a safe-driving brake.
it is shaped like the letter "S".
it applies a "Shock" to the brakes.
8. Air tanks must be drained because:
compressed air usually has some water in it. The water can freeze in cold weather and cause brake failure.
if one air system is low on pressure, the rear brakes will not be operating fully.
if you don't drain the tanks yourself, your battery fluid may drain out.
when you push the brake pedal, air is let into each brake chamber.
9. You are going down a steep grade. Once the vehicle is in the proper low gear, you should brake just hard enough to feel a slowdown, and then release the brakes when your speed has been reduced to ____ below your safe speed.
10 mph
5 mph
15 mph
20 mph
10. With the air pressure built up to governor cutoff, the maximum leakage rates per minute after the initial pressure drop are:
4 psi for single vehicles and 2 psi for a combination of 2 vehicles.
5 psi for single vehicles and 6 psi for a combination of 2 vehicles.
1 psi for single vehicles and 2 psi for a combination of 2 vehicles.
3 psi for single vehicles and 4 psi for a combination of 2 vehicles.
 
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NC Air Brakes Test

Number of questions: 25
Correct answers to pass:20
Passing score:80%
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