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North Carolina CDL Air Brakes Practice Test
Practice mode
Question
1
of 25
QUESTION 1 / 25
Are front wheel brakes effective under all conditions?
Choose one answer below.
A
Yes, they are effective under all conditions
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B
No, they can fail in certain conditions
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C
Only in dry conditions
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D
Only under low-speed conditions
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QUESTION 2 / 25
Which of the following is a common cause for air brake failure?
Choose one answer below.
A
Poor tire pressure.
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B
Contour of the braking surface.
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C
Low air pressure.
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D
Brake fluid leaks.
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QUESTION 3 / 25
Which condition can lead to premature brake wear in air brake systems?
Choose one answer below.
A
Low air pressure
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B
Excessive brake fluid
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C
Improper tire alignment
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D
Frequent use under heavy load
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QUESTION 4 / 25
What is another name for controlled braking?
Choose one answer below.
A
Precision braking
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B
Safety braking
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C
Squeeze braking
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D
Gradual braking
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QUESTION 5 / 25
What are the two main components of a basic air brake system?
Choose one answer below.
A
Compressor and wheel cylinder
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B
Compressor and reservoir
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C
Master cylinder and accumulator
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D
Vacuum pump and valve
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QUESTION 6 / 25
What must a driver ensure regarding air brake systems before operating a vehicle?
Choose one answer below.
A
That the fuel level is sufficient
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B
That the air pressure is above a minimum threshold
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C
That all warning lights are functional
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D
That tires are properly inflated
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QUESTION 7 / 25
What maintenance task is essential for the air brake system to function properly?
Choose one answer below.
A
Cleaning the air filter regularly
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B
Replacing traditional brake fluid
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C
Checking the air dryer for moisture
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D
Greasing the brake calipers
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QUESTION 8 / 25
What are the primary types of brakes available in air brake systems?
Choose one answer below.
A
Drum brakes and disc brakes
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B
Service brakes, parking brakes, and emergency brakes
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C
Electric brakes and hydraulic brakes
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D
Manual brakes and automatic brakes
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QUESTION 9 / 25
How can you confirm that the parking brake is properly engaged?
Choose one answer below.
A
The vehicle should roll freely
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B
The dashboard indicator lights must be off
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C
The cab controls must indicate it is set, and the vehicle should not roll
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D
The parking brake should make a clicking sound
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QUESTION 10 / 25
To correct a drive-wheel braking skid, what should the driver do?
Choose one answer below.
A
Apply more brake pressure
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B
Stop braking, turn quickly, and countersteer
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C
Accelerate out of the skid
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D
Steer in the opposite direction of travel
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QUESTION 11 / 25
How can you check the slack adjuster for movement?
Choose one answer below.
A
Swipe it with your hand
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B
Pull hard on each slack adjuster
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C
Observe it while braking
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D
Use a wrench to tighten
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QUESTION 12 / 25
How can a driver test for air leaks in the braking system?
Choose one answer below.
A
By measuring brake fluid levels
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B
By conducting a leak-down test
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C
By examining tire pressure
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D
By monitoring engine RPM
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QUESTION 13 / 25
How can you tell your brakes are fading?
Choose one answer below.
A
You hear a grinding noise
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B
Brakes smell burnt
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C
You have to apply the pedal harder to control speed
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D
Your vehicle pulls to one side when braking
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QUESTION 14 / 25
What indicates that your air brake system may have a leak?
Choose one answer below.
A
An audible hissing sound
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B
Increased stopping distance
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C
Lower air pressure than normal
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D
All of the above
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QUESTION 15 / 25
What type of maintenance should be performed to ensure air brake systems are functioning well?
Choose one answer below.
A
Regular tire rotation
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B
Routine inspection and maintenance of brake components
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C
Frequent washing of the vehicle
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D
Changing engine oil regularly
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QUESTION 16 / 25
Under normal conditions, what must a driver do first to engage the parking brakes?
Choose one answer below.
A
Press the brake pedal
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B
Let the air out of the spring brakes
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C
Turn off the engine
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D
Release the service brakes
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QUESTION 17 / 25
What action applies the parking brake in an air brake system?
Choose one answer below.
A
Releasing pressure from the air tanks
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B
Using the parking brake control
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C
Pressing the brake pedal
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D
Automatic engagement during a stop
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QUESTION 18 / 25
What indicates that the air brake system is fully charged?
Choose one answer below.
A
When the warning light activates
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B
When the pressure gauge reaches the normal operating level
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C
When all brakes are engaged
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D
When the compressor is silent
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QUESTION 19 / 25
What should you do immediately when a low air pressure warning comes on?
Choose one answer below.
A
Continue driving cautiously
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B
Stop and safely park as soon as possible
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C
Check the air pressure gauge
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D
Accelerate to build air pressure
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QUESTION 20 / 25
When should you perform a brake check during driving?
Choose one answer below.
A
Every time you start your vehicle.
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B
At the top of every hill.
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C
Before you turn or corner.
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D
Only when you hear a noise.
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QUESTION 21 / 25
At what air pressure will the spring brakes on a straight truck bring you to a stop?
Choose one answer below.
A
10 PSI
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B
20 PSI
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C
30 PSI
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D
40 PSI
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QUESTION 22 / 25
What is the correct method for making an emergency stop using air brakes with the stab braking method?
Choose one answer below.
A
Press brake pedal gently and hold
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B
Apply brakes, release when wheels lock, then reapply when rolling
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C
Pump the brake pedal rapidly
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D
Gradually decrease speed over time
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QUESTION 23 / 25
How often should you drain the oil and water from the bottom of compressed air storage tanks if you do not have automatic tank drains?
Choose one answer below.
A
After every drive
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B
At the end of each week
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C
At the end of each day of driving
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D
Only when the tank is full
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QUESTION 24 / 25
During cold weather, what should be done regarding the alcohol level if your vehicle has an alcohol evaporator?
Choose one answer below.
A
Check and fill the alcohol level
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B
Leave it empty until needed
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C
Replace the evaporator
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D
Monitor only occasionally
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QUESTION 25 / 25
When you apply the brakes, the brake shoes/linings are pressed against the:
Choose one answer below.
A
Brake pad.
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B
Brake drum.
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C
Brake line.
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D
Wheel rim.
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