Air Brakes CDL Test - FREE Florida CDL Practice Test

1. The Johnson bar is a valve that:

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

2. To operate a vehicle equipped with air brakes, you must pass the air brakes knowledge test. Why?

If you don't, you will only receive a CDL permit.
If you don't pass the air brakes test, you can't get a CDL.
If you don't pass the air brakes test, you will be restricted to driving vehicles without air brakes.
All trucks have air brakes.

3. If a load is 10 feet long, the minimum number of tie-downs required is:

4. Air tanks usually hold enough compressed air to allow the brakes to be used _________ even if the compressor stops working.

5. Which of the following is not a way to know when to change gears?

Use road speed (mph)
Use engine speed (rpm)
Check that the pressure gauge shows normal oil pressure
Watch your tachometer

6. The safety relief valve is usually set to open at ____ psi.

7. If you get stuck on the railroad tracks, the first thing you should do is:

stay in your vehicle and call 911.
scream for help.
try to move your vehicle until you see the train.
immediately get out of the cab and move away from the tracks.

8. Why should you check your mirrors regularly to know where other vehicles are around you?

To flash the brake lights if you are being tailgated.
To know whether you can make a quick lane change in an emergency.
To better assess your own speed.
To move out of their way if they want to get past.

9. The trailer hand valve should:

never be used for parking.
be used in driving.
never be used to test the trailer brakes.
All of the above.

10. Air tank drains:

are used to move air to the brakes.
protect the tanks and the rest of the system from too much pressure.
are used to remove water and oil from the air tanks.
should not be used in wet weather.

FL CDL AIR BRAKES PRACTICE TEST