CDL Air Brake Brake Fade and Downgrade Driving

Question 1

What is brake fade?

Accepted Answer

The loss of braking power caused by overheated brakes

Answer

Brake fade occurs when brakes overheat, causing a significant loss of braking effectiveness that can be extremely dangerous on long downgrades.

Question 2

What is the correct technique for driving down a long, steep grade with air brakes?

Accepted Answer

Select a low gear before starting down and use controlled, intermittent brake applications

Answer

Select a low gear before descending so engine braking helps control speed, and use controlled applications rather than continuous braking to prevent overheating.

Question 3

What is 'snub braking' when used on a downgrade?

Accepted Answer

Applying brakes firmly to reduce speed by about 5 mph, then releasing until speed rises again

Answer

Snub braking means applying brakes firmly to slow about 5 mph below your target speed, then releasing so brakes can cool before the next application.

Question 4

What is a safe speed limit when driving down a long, steep grade?

Accepted Answer

A speed at which you could still control the vehicle if brakes failed completely

Answer

Your safe downgrade speed is one at which you could still safely control the vehicle even if your brakes completely failed.

Question 5

How does brake fade affect stopping distance?

Accepted Answer

Stopping distance increases significantly as brakes overheat

Answer

As brakes overheat and fade, stopping distance can increase dramatically, making it impossible to stop within a safe distance.

CDL Air Brake - Commercial Driver's License Air Brakes Test Practice Test

CDL Air Brake - Commercial Driver's License Air Brakes Test Practice Test

CDL Air Brake Brake Fade and Downgrade Driving