CDL General Knowledge TestAir Brakes (if applicable)Medium
A driver is preparing to descend a long, steep grade. They are operating a vehicle equipped with air brakes. Which of the following braking techniques should be used to maintain a safe speed and prevent brake fade?
- AUsing a low gear and applying brakes firmly for short periods.
- BRelying solely on engine braking to control speed.
- CApplying the parking brake periodically to slow down.
- DLight, continuous pressure on the brake pedal.
Show answer & explanationAnswer & explanation
Correct answer: A. Using a low gear and applying brakes firmly for short periods.
When descending a long, steep grade, the best practice is to use a low gear to engage engine braking and then apply the service brakes firmly for short periods. This allows the brakes to cool between applications, preventing excessive heat buildup and brake fade.
Why the other options are wrong
- B. Engine braking alone may not be sufficient on steep grades, requiring supplemental use of service brakes.
- C. Using the parking brake (spring brakes) for slowing down while moving is dangerous and can cause severe damage or loss of control.
- D. Light, continuous pressure causes excessive heat buildup and brake fade.
Controlled Braking on Grades
To safely descend long, steep grades, use a low gear and apply the service brakes firmly for short periods to control speed and prevent brake fade.
- Low gear provides engine braking.
- Intermittent, firm braking allows cooling.
- Prevents brake fade from overheating.
Memory trick: Low gear, short and firm, keeps the heat from doing harm.