Wouldn't it be better to go ahead and take the system apart, flush it and fill with DOT 5? Silicone won't absorb water, will it? I think most military and goverment vehicles that may only see occasional use, or long storage periods, spec DOT 5. I've been using it in a couple of my old cars for 5 years+ without problems, and the brakes are about the only thing that will work after I leave a car set for over a year. (I'm not smart enough to start them occassionally)
