[DanEC]

I had the same issue with a Tilton master cylinder in my brake system on my ERA. I don't think it made it even 50 miles. The walls were scuffed up in it too. About all you can do is align everything as best as possible so that it has the straightest stroke possible and then hold your tongue just right and hope. Since I replaced it, I haven't had any further problems.

Strange that some scuff and some don't seem to. I did notice that the piston was a bit rough on the ends when I took it apart. I put a rebuild kit in it and held on to it as a spare. I smoothed the edges of the piston and honed the cylinder walls. My suspicion is that all pistons scuff a little in these masters and only the extra rough ones scar up the cylinder walls enough to leak.