I retrofitted the air tanks on my truck last year with the military kit that comes with two brass cable operated air valves and two cables. Through last Summer and Fall they worked flawlessly, eliminating my having to crawl under the truck to do this. This past winter however I took the truck out on a very cold below freezing day and I found that both valves seemed to be frozen. I could not dump the tanks. I imagine that there must have been water in the tanks that apparently froze the valves. Has this happened to anyone else, and if so how do you remedy it? Thanks, Lenny