The silca reversible chuck has a bit of a hidden "feature". The chuck cover also squeezes the rubber washer. So I loosen the end of the chuck, push it on the valve, then tighten the chuck compressing the washer. This seems to lengthen the life of the washer. I also spit in the end of the rubber washer which is a bit of "lube" which also lengthens the washer life.
Sheldon