By Wayne Schooling
•
January 3, 2025
Cold temperatures and water can lead to only one outcome – and ice has no place in a truck's air system. Frozen moisture can disable compressors, along with any of the multitude of air valves in the system. Plunging temperatures, like we have seen across much of the Lower 48 in recent weeks, will put air systems to the test. Compressed air always contains moisture, and when the air leaves the compressor, it’s hot. But as it travels through the line from the compressor to the air dryer, it cools, and that’s when the moisture in the compressed air condenses to liquid. If it's cold enough, that liquid will freeze, threatening the air supply to various systems, including transmissions, suspensions, and of course, brakes. A heavy truck's air compressor puts out 4-6 ounces of water during an average day’s operation; more when operating in regions of high relative humidity, and less when air is cold and dry. If all that water is sloshing around in your air reservoirs or some other spot further downstream, you could be in trouble when temperatures plummet.