Why are air brakes used on heavy commercial vehicles instead of hydraulic brakes?

Air brakes are the preferred system for heavy commercial vehicles largely because they are capable of applying greater force necessary to handle the demands of heavy loads safely and efficiently. When a driver uses the brake pedal, compressed air is sent to the brake chambers, which engage the brake shoes against the drums, creating a strong braking force. This is especially important for large vehicles that can weigh significantly more than standard cars, where conventional hydraulic brakes might struggle to generate sufficient force to stop.

Additionally, the nature of air brakes allows for consistent performance regardless of the heat buildup that occurs during prolonged or heavy braking, a common issue in hydraulic systems. Heavy vehicles often need to rely on their brakes more frequently and with increased intensity, making the robust force generation of air brakes essential for maintaining safety on the road.

While air brakes may require specific training and are generally more complex, their ability to handle the requirements of heavy loads is unmatched compared to hydraulic systems, which are better suited for lighter vehicles.