Air Brakes CDL Test - FREE North Dakota CDL Practice Test

1. Which of the following is NOT correct? An ABS system:

is a safety anti-skid braking system.
reduces the braking pressure to a safe level.
helps you stop faster.
helps you avoid wheel lock up.

2. The Johnson bar is a valve that:

works the trailer brakes.
reduces the braking pressure to a safe level.
keeps air from going out if the air compressor develops a leak.
is installed in the first tank the air compressor pumps air to.

3. Supply pressure gauges tell drivers:

how much pressure is in the air tanks.
how much air pressure they are applying to the brakes.
how much pressure the relay valves should send to the trailer brakes.
All of the above.

4. Which of the following is TRUE about dual air brake systems?

A dual air brake system has 2 separate air brake systems.
most heavy-duty vehicles use dual air brake systems.
Each brake system has its own air tanks, hoses and lines.
All of the above.

5. If your truck catches fire, the first thing you should do is to:

get off the vehicle, open the hood and start shooting foam to keep the engine cool.
pull into a service station and call for help.
pull off the road and park in an open area.
get the vehicle off the road and park near other vehicles.

6. Why must air tanks be drained?

There might not be enough antifreeze in the system.
The alcohol evaporator might stop working.
The water can freeze in cold weather and cause brake failure.
Your transmission fluid may drain out.

7. If the air pressure gets too low:

the brakes will not work.
the brakes will lock up.
ABS will help maintain vehicle control.
you should set the parking brake.

8. Radial and bias-ply tires:

should be used together only when driving in packed snow.
should be used together.
should be used together only during bad weather.
should not be used together.

9. To control your speed on a downgrade, you should:

10. To prevent rollover, you should:

put the lightest parts of the cargo under the heaviest parts.
place the cargo near the front of the trailer.
place the cargo near the rear of the trailer.
keep the cargo as close to the ground as possible.

ND CDL AIR BRAKES PRACTICE TEST