Why do air brakes take longer to stop than hydraulic brakes?

Air brakes take longer to stop than hydraulic brakes because it takes longer for air to flow through the lines.

In hydraulic brake systems, the braking action is achieved by the transmission of hydraulic fluid, which is pressurized by the master cylinder, to the brake calipers or wheel cylinders. This hydraulic fluid quickly and efficiently transfers the pressure from the driver's input to the brake components, resulting in a rapid and responsive braking action.

On the other hand, in air brake systems, the braking action is achieved by the transmission of compressed air through the air lines to activate the brake chambers. When the driver presses the brake pedal, it initiates the release of air pressure, which takes time to flow through the various air lines and reach the brake chambers. The time it takes for the air to flow and apply the brakes results in a slightly longer response time compared to hydraulic systems.

The longer response time of air brakes is due to the nature of compressed air as the medium for transmitting the braking force. While air brakes are still effective in providing sufficient stopping power, the delay in air pressure transmission can result in a slightly longer stopping distance compared to hydraulic brakes.