Which condition requires immediate attention during a maintenance check?

During a maintenance check, visible fluid leaks require immediate attention because they can indicate serious underlying issues with the bus's systems. Fluid leaks can come from various components, such as the engine, transmission, or braking system. These leaks could lead to critical failures if not addressed promptly, potentially compromising the safety of the vehicle and its passengers. It is essential to investigate the source of the leak, as it may not only signal a need for repairs but also pose risks such as fire hazards or brake failure.

Normal wear and tear on tires, low windshield washer fluid, and worn-out seat covers, while important to monitor and address, do not typically pose immediate risks. Tires can be replaced during routine maintenance, low washer fluid can be replenished easily, and seat covers are more about comfort and aesthetics than safety. Thus, focusing on visible fluid leaks is crucial for maintaining the operational integrity and safety of the school bus.