Air tank drains:

Question

Compressed air in an air brake system usually contains a certain amount of water and compressor oil. The water and oil can damage the brakes if left to accumulate in the system. Manually operated air tank drains must be opened daily to remove this build-up.

Accepted Answer

Are used to drain water and oil from the air tanks.

Answer

Allow rain water to enter the tanks.

Answer

Should never be opened.

Answer

Must remain open while driving.