What happens when you apply pressure to the brake pedal in a vehicle equipped with air brakes?

When you apply pressure to the brake pedal in a vehicle equipped with air brakes, you are pushing against both a spring and air pressure to activate the braking system. This process involves the use of compressed air to engage the brakes effectively.

In air brake systems, when the pedal is pressed, it opens a valve that allows compressed air to flow into the brake chambers. This air pressure pushes a diaphragm or a piston, which in turn forces the brake shoes or pads against the brake drum or disc, creating the friction necessary to slow down or stop the vehicle. The spring is also involved in returning the brake components to their original position when the brakes are released, ensuring that they disengage properly and allowing the vehicle to resume normal operation.

Understanding this mechanism is crucial for CDL drivers because proper function and awareness of air brake systems are vital for safe vehicle operation.