CDL · Air brakes
Air-braked trucks and buses most often use which kind of brake at the wheels?
Correct answer: S-cam drum brakes.
Answer options
- AWedge brakes
- BDisc brakes
- CS-cam drum brakes Correct
Why
Air brake systems can use S-cam drum, wedge or disc brakes at the wheels, but the S-cam drum design is by far the one seen most often on air-braked vehicles.
About this question
Topic: Air brakes License: CDL
Part of these practice sets:
Where it applies: Asked in every state.
Practice the whole set
This question is part of How Air Brakes Work (18 questions). Take the full set and check your score.
Practice How Air Brakes WorkMore questions from How Air Brakes Work
- Your air brake system's safety relief valve starts letting air escape. What does this tell you?
- On an air brake system, what pressure does it normally take for the safety valve to open?
- In an air brake system, which statement about the storage tanks is true?
- In an air brake system, what is the purpose of the air storage tanks?
- In an air brake system, what is the compressor governor responsible for?
- If the air compressor springs a leak, which valve keeps the stored air from escaping?
- Besides the service brake and the parking brake, what is the third braking system that makes up air brakes?
- Which part of the vehicle drives the air compressor?
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.