South Carolina CDL — Air Brakes: Parking & Stopping Practice Test

Question 1

How do you test that the parking brake will hold?

Accepted Answer

Apply the parking brake, then tug lightly against it while in a low gear — Stop the vehicle, apply the parking brake, and tug gently against it in a low gear to confirm it holds.

Answer

Rev the engine to cut-out pressure and listen for leaks

Answer

Roll downhill in neutral and apply the pedal

Answer

Push the brake pedal all the way to the floor

Question 2

When should you avoid setting the parking brakes?

Accepted Answer

When the brakes are very hot, or very wet in freezing temperatures — Hot brakes can be damaged by setting the parking brakes, and very wet brakes can freeze in cold weather; in those cases let hot brakes cool or dry wet ones, and chock the wheels.

Answer

Any time the vehicle is fully loaded

Answer

Whenever the engine is still running

Answer

On any downhill grade

Question 3

If your vehicle's tanks have manual drains, how often should you drain them?

Accepted Answer

At the close of each driving day — Manual tanks should be drained completely at the close of each driving day to clear out the water and oil that collect inside.

Answer

Once a week

Answer

Only when the buzzer sounds

Answer

Every time you shut off the engine

Question 4

Why should you avoid pushing down the brake pedal while the spring brakes are already applied?

Accepted Answer

The combined spring and air forces could damage the brakes — Adding pedal air pressure on top of the applied springs can overload and damage the brakes, so it is best to make a habit of not doing it.

Answer

It drains the alcohol evaporator

Answer

It resets the governor cut-out point

Answer

It turns off the stop lights

Question 5

What should you always do before leaving your vehicle unattended?

Accepted Answer

Apply the parking brakes or chock the wheels — Never leave the vehicle unattended without setting the parking brakes or chocking the wheels, or it could roll away and cause injury or damage.

Answer

Drain the air tanks completely

Answer

Leave the engine running to keep pressure up

Answer

Release the spring brakes to prevent freezing

Question 6

On newer air brake vehicles, how do you set the parking brakes?

Accepted Answer

Pull out the yellow, diamond-shaped control knob — Newer vehicles use a yellow, diamond-shaped push-pull knob; pulling it out applies the spring/parking brakes and pushing it in releases them.

Answer

Push down and hold the brake pedal

Answer

Turn a round blue knob a quarter turn

Answer

Move a modulating lever to its middle position

Parking & Stopping

Study questions with answers

1. How do you test that the parking brake will hold?

2. When should you avoid setting the parking brakes?

3. If your vehicle's tanks have manual drains, how often should you drain them?

4. Why should you avoid pushing down the brake pedal while the spring brakes are already applied?

5. What should you always do before leaving your vehicle unattended?

6. On newer air brake vehicles, how do you set the parking brakes?

More CDL — Air Brakes topics

Practice Parking & Stopping in another state