Why must air tanks be drained?

Air tanks must be drained primarily to remove moisture and oil that accumulate within the tanks. Compressed air naturally contains water vapor, which can condense into liquid form due to temperature changes or pressure drops. If this moisture is not drained, it can lead to several issues, such as corrosion of the tank and other components in the air system, reduced efficiency of the braking system, and potential freezing during colder temperatures, which can interfere with air supply.

In addition to moisture, oil can also build up in the air tanks, especially if the air compressor is not equipped with an adequate air dryer. The presence of oil can further compromise the functionality of the braking system, as it may affect the performance of the brake components and lead to premature wear or failure. Regularly draining the air tanks ensures that the air system remains clean and operational, contributing to overall vehicle safety and performance.