stripped

[gort69]

I don't like the idea of a thread repair insert there. Any that I've seen require that you drill & tap the current threads significantly oversize in order to thread the insert in. The C5 caliper - as I recall - has a shallow machined counterbore against which the crush washer seals. By drilling the hole larger, you'll lose most if not all of that machined sealing surface.

One of the nice things about using the C5 brakes is that they're affordable and plentiful. I wouldn't even waste my time messing with it considering how important a good seal is there.

[Ishmael]

I'm going to take it to an automotive machine shop where I know the guy is into sports cars. I'll see what he thinks about cleaning it up to see if a 1.5 can go in. If not, I'll spring for a new caliper - maybe two.