If you're sure that the brake fluid has been changed religiously - more often than Honda recommends, say every 2 years - the cylinder bore might be in good enough shape to rebuild but then the seals would likely be in good enough condition that the thing would not be failing. More likely rebuilding would be a waste of time and effort.
Rgds, George Macdonald
"Just because they're paranoid doesn't mean you're not psychotic" - Who, me??
I've not had good luck with diy rebuilding of master or brake cylinders. Usually if the cylinder is leaking it has more internal corrosion than can be cleaned up with a hone.
You can get a replacement for $87 at www.thepartsbin.com
