What is the purpose of the brake reservoir in an air brake system?

The purpose of the brake reservoir in an air brake system is to store compressed air that is necessary for operating the brakes. When a driver applies the brakes, this stored compressed air is used to activate the brake chambers, which in turn apply pressure to the brake shoes or pads, thereby slowing down or stopping the vehicle. This function is crucial because it allows for efficient and effective braking in heavy vehicles, which often require significant stopping power due to their size and weight.

The reservoir ensures that there is always a supply of compressed air available, which is essential for the proper functioning of the air brake system, especially in scenarios that involve frequent braking or high-demand situations. Therefore, having a dedicated reservoir for compressed air is vital to maintain the performance and safety of the air brake system in commercial vehicles. The other options, related to storing coolant, hydraulic fluid, or preventing debris, are not relevant to the function of the brake reservoir in an air brake system.