AL CDL Combination Practice Test (2024)

1. Do NOT use the parking brakes:

when you park for less than two hours.
when you leave your vehicle.
if the brakes are very hot.
to test that they work.

2. How can you tell if a converter dollie has ABS?

There is a yellow lamp on the left side of the dolly.
There is an ABS plaque on the right side of the dolly.
There is an ABS system on the right side of the dolly.
There is a red lamp on the left side of the dolly.

3. You supply air to the trailer brake system by:

connecting the tractor service air line to the trailer service glad hand.
pushing in the trailer air supply knob.
pulling out the trailer air supply valve.
plugging the electrical cord into the trailer.

4. If you must make an emergency stop, you should:

apply the brakes as hard as you can to lock them.
brake in a way that will keep your vehicle in a straight line.
use the hand brake before the brake pedal.
None of the above.

5. What happens when the center of gravity of a truck moves higher up from the road?

The vehicle is more stable while turning.
It becomes much easier to downshift at the right rpm.
The truck becomes easier to turn over.
It is easier it is to turn around corners.

6. To prevent rollover, drivers of combination vehicles should:

brake while turning.
make sure the cargo is not centered and spread out.
keep the cargo as close to the ground as possible.
keep the load is to one side.

7. Cargo should be properly covered:

to protect people from spilled cargo.
to protect the weather from the cargo.
to block your view or someone else’s.
All of the above.

8. Which of the following is true about the trailer hand valve?

It should be used only to test the trailer brakes.
The trailer hand valve works the trailer brakes.
If used in driving it could cause the trailer to skid.
All of the above.

9. When the trailer breaks away or develops a bad leak, the tractor protection valve will close automatically and:

the trailer supply valve will stay open.
the tractor will lose all air pressure.
the trailer emergency brakes will come on.
the engine will shut down.

10. Before leaving your vehicle unattended, you should:

CDL COMBINATION PRACTICE TEST (AL)