Before driving a vehicle with air brakes, what crucial check should be performed?

Inspecting the functionality of the air brake system is essential before driving a vehicle equipped with air brakes. Air brakes operate differently than hydraulic brake systems, relying on compressed air to apply braking force. Therefore, ensuring that the air brake system is functioning properly is critical for safe vehicle operation.

This check includes verifying that the air tanks are adequately filled with compressed air, confirming the operation of the brake valves, and ensuring that there are no leaks in the air lines. Proper functionality is vital for effective braking, which is particularly important given the larger size and weight of vehicles that typically use air brakes, such as trucks and buses. Insufficient air pressure or faults in the system can lead to brake failure, which poses significant hazards on the road.

While checking fuel levels, cleaning headlights, and adjusting side mirrors are important for vehicle operation, they do not directly pertain to the safe functioning of the braking system, which is paramount for driving safely, especially under various load conditions.