Air Brakes CDL Test - FREE Mississippi CDL Practice Test

1. An alcohol evaporator:

protects the air brake system from too much pressure.
used to reduce the chance of the front wheels skidding.
to hold compressed air.
is used to reduce the risk of ice in air brake valves and other parts during cold weather.

2. With the air pressure built up to governor cutoff, the maximum leakage rates per minute after the initial pressure drop are:

5 psi for single vehicles and 6 psi for a combination of 2 vehicles.
1 psi for single vehicles and 2 psi for a combination of 2 vehicles.
4 psi for single vehicles and 2 psi for a combination of 2 vehicles.
3 psi for single vehicles and 4 psi for a combination of 2 vehicles.

3. When going down grades, you should:

rely solely on engine braking to reduce your speed.
put the transmission in Neutral.
downshift to a lower gear.
shift up.

4. The most common foundation brakes found on vehicles with air brakes are the:

5. On a tractor-trailer equipped with a trailer brake hand valve, the hand valve can be used to:

hold compressed air.
keep from rolling back.
reduce the chance of the front wheels skidding.
prevent movement of cargo.

6. The safety valve is usually set to open at:

7. Axle weight is:

the value specified by the manufacturer as the loaded weight of one axle.
the weight transmitted to the ground by one axle or one set of axles.
the maximum safe weight your tires can carry at a specified pressure.
the weight of all the axles added together.

8. ABS:

improves your visibility at night.
helps you avoid skids caused by over braking.
helps you stop faster.
may cause your wheels to lock when you break hard.

9. The air compressor governor:

controls when the air storage tanks will pump air into the air compressor.
stops the compressor from pumping air.
allows the compressor to start pumping air when the tank pressure rises to the "cut-out" pressure.
All of the above.

10. You must take the CDL skills tests in the type of vehicle for which you wish to be licensed. If your test vehicle does not have air brakes:

you will be restricted to driving vehicles without air brakes.
you'll need to take another knowledge test about air brakes.
you won't receive a CDL.
you'll have to immediately retake your test using another vehicle.

MS CDL AIR BRAKES PRACTICE TEST