The spring park brake system draws air from which tank?

The spring park brake system is designed to operate safely and effectively in various conditions. It draws air from the tank with the highest pressure to ensure that it has sufficient force to engage the parking brakes. This is crucial because the parking brake needs to be reliable in holding the vehicle stationary when it is not in motion.

By utilizing air from the tank with the highest pressure, the system ensures that there is enough air volume and pressure to fully release the wheel brakes when operating and to engage the parking function when needed. This design choice maximizes the reliability of the braking system, ensuring that the vehicle remains secure when parked and that the brakes respond appropriately when demanded.

Other options may suggest drawing air from tanks that would not provide adequate pressure or volume needed for effective operation, leading to potential brake failure or inefficiency in engaging the parking brake. Hence, drawing from the tank with the highest pressure is a critical operational feature for the safety and functionality of the spring park brake system.