[Lynn]

I would not even consider changing over an assembled existing system. Dot 3 and dot 5 are not compatible. Don't know about one drop turning it to jelly, but does that really matter? How are you going to remove every bit of the dot 3?

The only time I considered dot 5 was when I was putting my car back together after rebuilding EVERY part of the brake system and replacing the lines with stainless. I know some restorers swear by the dot 5 because if you spill a bit, it won't remove paint like dot 3.

I chose the 3 anyway. I am a firm believer that brake fluid needs to be flushed / replaced every 3 or 4 years regardless of whether the car is driven daily or only occasionally. It is a maintenance requirement, just like changing oil.