I know what the article abour residual valves says in MP but you have to read alot more than one article and get the big picture. My blown 32 has no residual valves runs a cool 550 h.p. has 18 in. LIVE vac. and the master is even under the floor and the brakes are perfect. Hum! Oh whoa is me. Why does my car stop so well? could it be because I have read the book on brake systems. I don't mean to be a smarty pants Mr. Techinspector But I do know brakes and MP is the best in the business and with their tech information in their book you can't go wrong. You just got to read it all not just part of it.