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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 Maryland CDL knowledge test. The MD 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 Maryland CDL Manual. Take this MD CDL practice test now to prepare for the actual air brakes test!
1. The use of brakes on a steep downgrade is:
a supplement to the braking effect of the engine.
much more effective than the engine braking effect.
the main braking factor.
dangerous, and should be avoided at all costs.
2. A passive railroad crossing is one that:
requires you to stop and wait until the traffic control device installed at the crossing tells you to proceed.
has a traffic control device installed at the crossing to regulate traffic.
does not have any type of traffic control device.
has at least two traffic control devices installed at the crossing to regulate traffic.
3. Most heavy duty vehicles use ___ air brake systems for safety.
single
triple
dual
reduced
4. Spring brakes are usually held back by:
the brake pedal.
air pressure.
the antilock braking system.
modulating control valves.
5. The parking or emergency brakes of trucks or buses must be held on by:
air pressure.
fluid pressure.
spring pressure.
hydraulic pressure.
6. In newer vehicles with air brakes, you put on the parking brake:
using a P-shaped, yellow control knob.
moving the orange push-pull lever to the right.
using a diamond-shaped, yellow, push-pull control knob.
placing the transmission in Park.
7. If your vehicle does not have automatic air tank drains, how often should you drain air tanks to remove moisture and oil?
At least once a month.
Once a week.
Every 4 hours.
At the end of each working day.
8. You are coming down a long, steep downgrade. Which of the following is a sign that your brakes may have started to fade?
You have to apply your brakes harder and harder to get the same stopping power.
The brake pedal feels spongy or goes to the floor.
The steering feels heavy.
You hear a loud "bang".
9. To avoid becoming a distracted driver you should:
adjust all vehicle controls and mirrors while driving.
eat and drink while you drive.
not engage in complex conversations with others.
not turn off all communication devices.
10. If your brakes fail while you are driving on a downgrade, you should:
take the least hazardous escape route you can.
immediately start looking outside your vehicle for something to stop it.
use an escape ramp if it's available.
All of the above.
 
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MD CDL Air Brakes Test

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