Having a dual master seems like a good idea, one which I had thought about. However in a recent issue of Smoke Signals the magazine of the Pontiac owners club, a professional mechanic discouraged the use. He has been writing a column on rebuilding brakes on older vehicles and says that if the system is maintained properly a single MC will be just as good.
I can't recall the gist of the article but one comment was about his experience when the rear brake line broke and he was unaware of driving with just the front brakes in operation. Perhaps someone here has the article and can quote from it.
