CDL Air Brakes Test (2024) - FREE Mississippi CDL Practice Test

1. If stopped on a hill, how can you start moving without rolling back?

Press on the gas pedal, even if you have to roll back a little.
Partly engage the clutch before you take your right foot off the brake, put on the parking brake if necessary.
Release the parking brake before you have applied enough engine power to keep from rolling back.
None of the above.

2. When you make a quick lane change, the crack-the-whip effect can:

turn the trailer over.
make it harder to turn without skidding.
improve your traction.
the trailer to swing wide to the left.

3. Supply pressure gauges tell drivers:

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

4. An ABS system:

gives you more control over the vehicle during braking.
helps you avoid skids caused by over braking.
keep your wheels from locking when you brake hard.
All of the above.

5. Air tanks must be drained because:

if one air system is low on pressure, the rear brakes will not be operating fully.
if you don't drain the tanks yourself, your battery fluid may drain out.
when you push the brake pedal, air is let into each brake chamber.
compressed air usually has some water in it. The water can freeze in cold weather and cause brake failure.

6. If your vehicle catches fire, you should pull over:

7. ABS:

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

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

9. How can you tell if your vehicle is equipped with ABS (anti-lock braking system)?

ABS is required on all vehicles manufactured on or after 2000.
ABS is required on all vehicles manufactured on or after 2005.
There is no way to tell, ABS is still optional on all vehicle types.
Trucks, buses, trailers, and converter dollies built after 1998 are required to have ABS.

10. While driving, you should use your mirrors to:

know where other vehicles are around you.
check where the rear of your vehicle is while you make turns.
check the condition of the tires and cargo.
All of the above.

MISSISSIPPI CDL AIR BRAKES PRACTICE TEST