I'm still trying to figure it all out myself Greg. What I have learned over the years is that the residual valves are necessary on our old trucks that have the MC located on the frame being the same elevation as the wheel cylinders. They are located either in the MC or external of the MC to keep a slight pressure at the brakes otherwise the fluid would be allowed to gravity drain back to the MC thus requiring more peddle travel the next time the brakes are needed. I did need to install them when I converted my truck to a dual MC years ago. As far as my concern about MC bore size I think I'm going with the 1" power MC setup and rely on a Proportioning valve to adjust the flow to the rear brakes. Just need to find out if the new MC has the residual valves built in. Maybe If we had this topic in the "Driveline" forum we would have been getting more views and input from the experts.
