Dot 5 is silicone fluid No moisture when parked for long periods of time.Donot mix with Dot3.everthing must be flushed if going to Dot5.pays in the long run.I've used it for 11 years now,no problem.The millitary only uses dot 5.No moisture.water is a killer when things set for long times
That's not exactly correct. Older vehicles with vented master cylinders, like the '59 and earlier GM trucks, can still get moisture in the system. It tends to condense in the lowest piont in the system, making a water "slug" in the lines. When the brakes get hot, the water will vaporize, causing a low pedal and poor brake performance. There is also an issue with the water freeezing in the lines, causing total brake failure. See Bob Adlers article in the current issue of Vintage Truck, which covers that particular problem.
