I've just installed a new (to me) and working brake booster and master cylinder that had previously been run on DOT 5 fluid that I pulled from a friends '68 142. My setup most likely never saw that (I'm second owner). I know it is not recommended to mix DOT 5 w/ the others. Any advice out there? If I shouldn't mix the two, how should I go about flushing the system? Should I run DOT 5 to flush everything, then bleed it all out and then put in fresh DOT 5? I also have working rear calipers that have been run on DOT 5, but the ones currently on the car are working so I don't really want to change them, not that it would be much, but you know.

Part two: my '71 145S had a 2 crimp style booster and I replaced it with a 1 crimp style but used a known working master cyl. that was mated to it. This shouldn't be an issue, right? I know from some past threads that there seems to be differring opinions on master cyl/brake booster combos. The one thing I did notice when putting the single crimp style in was that the check valve was located at the 9 o'clock instead of the 12 o'clock of the 2 crimp style. That shouldn't make a diff, right?

Thanks,
Jay