New Jersey Air Brakes Practice Test: Prep, Practice Exam & Questions

The component that stores compressed air in an air brake system is the air storage tanks. These tanks are essential for maintaining a reservoir of air pressure, which is necessary for the operation of the entire braking system. When the air compressor generates compressed air, it is directed into these storage tanks where it is kept until it is needed for braking action.

Having adequate air storage is critical because it ensures that there is enough pressure available to activate the brake cylinders effectively when the driver applies the brakes. This mechanism allows for quick and reliable braking response, which is vital for safety in heavy vehicles.

In contrast, the brake relay valve is responsible for controlling the flow of air to the brake chambers but does not store air. The compressor unit generates the compressed air but does not hold it; its job is to refill the air storage tanks. The brake pedal is the mechanism that the driver operates to engage the brakes, but it does not have any function related to the storage of compressed air.