Ditto on the new M/C!
Have you also rebuilt/replaced wheel cylinders, etc.? Older brake systems have a habit of springing leaks when they're subjected to the operating pressure of a new master cylinder, so it's best to do a full rehab while you're at it. Don't forget the rubber flex lines to the front wheels and the rear end, as they can collapse internally and hold pressure in the brakes, resulting in wear and/or pulling to one side when the brakes are applied.
I like to do a flush of the brake lines, etc., with alcohol to remove accumulated crud and old fluid, then do enough bleeding to purge any leftover alcohol out of the system. Since brake fluid is made of alcohol and glycerine, plus other additives, the alky won't damage the rubber parts.
Jerry
