CDL · CDL general knowledge
On a steep downhill grade, what should do most of the work of slowing your vehicle?
Correct answer: Engine braking.
Answer options
- AThe parking brake
- BEngine braking Correct
- CThe service brakes
Why
Choose a low gear before starting down so engine compression holds your speed back; the service brakes should only supplement engine braking, which keeps them cool enough to work when you need them. The parking brake is not meant for slowing a moving vehicle.
About this question
Topic: CDL general knowledge License: CDL
Part of these practice sets:
Where it applies: Asked in every state.
Practice the whole set
This question is part of Mountain Grades and Brake Fade (16 questions). Take the full set and check your score.
Practice Mountain Grades and Brake FadeMore questions from Mountain Grades and Brake Fade
- Your brakes give out while you are going down a long grade. What is the best thing to do?
- Using the service brakes too much makes them overheat. What can that excess heat do?
- On a long, steep downgrade, your speed has crept up to your "safe" speed. About how far below that speed should you brake before releasing the brakes?
- Partway down a long, steep grade, your brakes overheat and stop working. What is your best course of action?
- Which of these can make your brakes fade?
- On a long, steep downgrade, which braking method should you use?
- Your tanker's brakes have failed and an escape ramp for trucks lies ahead. Should you use it?
- What is an escape ramp, like the one shown, meant for?
Practice on your phone.
Practice here in your browser, or use the app with the same questions and explanations. It's free on the App Store.