Manitoba Airbrake Practice Exam

How do spring brakes operate in an air brake system?

1. They require electrical power to function

2. They apply brakes when air pressure is released

3. They enhance the braking speed

4. They store energy for future use

The correct answer is: They apply brakes when air pressure is released

In an air brake system, spring brakes function by engaging when air pressure is released. This mechanism typically serves as a safety feature, ensuring that the brakes activate if there is a loss of air pressure, such as in the case of a system failure. The spring brakes use large, powerful springs that are compressed when air pressure is applied to the brake system. When that air pressure drops, the springs are released, causing the brakes to apply automatically. This is particularly crucial in commercial vehicles where a failure in the air brake system could result in a loss of control. By automatically applying the brakes in such situations, spring brakes help to prevent accidents and improve safety on the road. They are an essential component of the overall braking system, working in conjunction with service brakes (which are typically powered by compressed air) to provide effective stopping power.