The difference is in how they front brakes work. Most master cylinders will apply the rear brakes just a touch before the fronts. If you hook them up backwards, it will still stop, it just won't feel right during a quick stop. I have done it! The power brake master cylinders are different from the manual brake ones. The difference is in the bore size and where the resivoirs are. There is a lot going on in the master cylinder other then just pushing fluid! Joe
