When I rebuilt the entire brake system 7 years ago I honed all the cylinders, this time the master did not need a hone job, the brake fluid was cloudy but did not leave any rust or pitting. The very small pin hole in the master had sludge and the check/pressure retention valve has some rust, along with the vent hole in the cap being clogged. Basically just clean-up, new kit, paint. When I removed the hard line from the master to the HydroVac and a small line in the front, they looked like new on the inside. I used copper-nickel when I did the job originally.
