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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 Louisiana CDL knowledge test. The LA 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 Louisiana CDL Manual. Take this LA CDL practice test now to prepare for the actual air brakes test!
1. You should drain your air tanks:
at the beginning of each trip.
at the end of each working day.
every month.
at least once a week.
2. During a trip you should check:
temperature gauges.
pressure gauges.
All of the above.
3. Vehicles with air brakes require more stopping distance than vehicles with hydraulic brakes. Why?
It takes one half second or more for the air to flow through the lines to the brakes.
Air brakes use different brake drums.
Stopping distance for vehicles with air brakes is made up of six different factors.
When driving vehicles with air brakes, the average perception distance increases from 400 feet to 2200 feet.
4. Brake fade results from, and is affected by:
brakes out of adjustment.
excessive heat caused by not relying on the engine braking effect.
excessive heat caused by using the brakes too much.
All of the above.
5. Which of the following statements is true?
Under-inflated tires will NOT cause a vehicle fire.
There is no way that short circuits due to damaged insulation can cause a vehicle fire.
Poor cargo ventilation is a common cause of fire.
Carrying a properly charged and rated fire extinguisher will help prevent fires.
6. The air compressor governor controls:
the speed of the air compressor.
the air pressure applied to the brakes.
when air tank pressure falls below the “cut-out” level.
when the air compressor will pump air into the air storage tanks.
7. Emergency brakes are:
not required on buses.
required on all vehicles.
not required on doubles.
not required on commercial vehicles with air brakes.
8. If you must make an emergency stop, you should:
use the hand brake before the brake pedal.
brake in a way that will keep your vehicle in a straight line.
apply the brakes as hard as you can to lock them.
None of the above.
9. When you make a quick lane change, the crack-the-whip effect can:
improve your traction.
make it harder to turn without skidding.
the trailer to swing wide to the left.
turn the trailer over.
10. If the spring brakes do not release when you push the trailer air supply control, you should:
pump the brakes.
rev or lug the engine.
check the electrical cables.
check the air line connections.
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LA CDL Air Brakes Test

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