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

The function of the air reservoir in an air brake system is to maintain brake pressure. The air reservoir stores compressed air that is used in the braking process. When the brakes are applied, air from the reservoir is released to engage the brake components, allowing the vehicle to slow down or stop effectively. This storage capability ensures that there is a sufficient supply of air pressure available for consistent and reliable brake performance, helping to manage the demands of the braking system over time, especially during prolonged use.

The other options, while related to different systems or functions within a vehicle, do not pertain to the specific role of the air reservoir in an air brake system. The air reservoir does not deal with hydraulic fluid, cooling, or temperature monitoring in relation to the braking mechanism. Its primary and critical function is to ensure that adequate air pressure is available to perform braking actions safely and effectively.