If you have a very fine stone hone and use extreme care, there is no
reason why the things can't be honed.
I did both master cylinders, the rear wheel cylinders and the clutch
slave in Huxley, the Spit about 3 years ago and I have had no leaks
> I've just about completed the brake mc rebuild on the 65 4A and wonder about
> the advisability of honing the cylinder. I seem to recall hearing bad things
> about doing that and that it can make matters worse. It leaked only slighty
> (like being slightly pregnant, I know!) and the condition of the old seals
> explained the leak quite suffixiently. The cylinder looks fine to the naked
> eye but.....:-~. Do the possibilities of over-reaming it outweigh the
> benefits of honing?
"If you can't excel with talent, triumph with effort."
-- Dave Weinbaum in National Enquirer