What must a driver ensure regarding air brake systems before operating a vehicle?

Before operating a vehicle equipped with air brakes, it is essential for the driver to ensure that the air pressure in the system is above a minimum threshold. This is crucial because air brakes rely on compressed air to function properly. When the air pressure is below the necessary level, the brakes may not engage effectively, increasing the risk of a collision or an inability to stop the vehicle safely.

Maintaining adequate air pressure ensures that the brake system can respond promptly and efficiently. Most air brake systems are designed with safety features that monitor air pressure, and vehicles typically have specific pressure settings that indicate optimal operating conditions. For instance, many systems require a minimum pressure of around 90 psi for adequate braking performance. If the pressure falls below this threshold, it could activate warning signals on the dashboard, alerting the driver to inspect the system.

Ensuring proper air pressure is a fundamental safety measure that helps maintain control and operational reliability of the vehicle's braking system.