The Stovebolt Site Forums The Shop Area Engine Shop Brake plumbing with master cyl under floor?

OK heres the question - Disc front drum rear dual master cylinder mounted under floor with booster - I know I need a combination valve and have been told I also need a 2 lb. residual valve for the fronts and a 10 lb. residual valve for the rears. I have acquired all of these things but now I'm wondering what goes where in what order? Aside from the obvious of course. Do the residuals goe between the master and the combination valve or between the combination valve and the wheels? If the latter the next question would be do I need 2 residual valves for the front or do I plug one of the line outs from the combination valve and only use one then spit the line and go to each front after the residual valve?
Now isn't that a confusing mess?
I just don't want to have to goe back and change it all after the body/bed is all back on. Lots easier to do with an open chassis.
Sorry for the long post but I have never upgraded and plumbed one with the master cylinder under the floor before and am learning, I hope!

This vendor has this nice diagram in their tech support section which addresses your question.

http://www.mpbrakes.com/uploads/documents/discdrumdiagram.pdf

It may get you started in the right direction. I'm sure others can give more advice.

Hy Guys, If the master cylinder is a disc/drum master cylinder, then a residual presure valve will not be required for the rear brakes, as it is already incorporated into the master cylinder. However I think most suppliers supply only disc/disc master cylinders now so a residual presure valve would be required in both circuits, hope that helps.

I have the same brake setup as you. I was told by Wilwood that a combination valve is not needed. They told me to use residual pressure valves on the front and rear. Also they told me to use a proportioning valve on the rear to set brake bias. Thats it.

From Wilwood Tech Center
Residual Pressure Valves
Use 2lb. RPV's when the master cylinder is mounted below the level of the disc brake calipers to prevent brake fluid from draining back down into the master cylinder. Use 10 lb. RPV's with all drum brake applications to offset return spring tension.

proportioning valve
It is typically installed in the rear brake line to reduce braking efficiency and compensate for premature wheel lockup; a result of incorrect front to rear brake bias. An adjustable proportioning valve permits incremental adjustments to fine tune brake bias.

There are numerous approaches to this issue. I did mine 7 years ago and have excellent brakes. 8" dual diaphram power booster,
Corvette master, proportioning valve. In this application the residual valve is built into the master cylinder.
Fred

Thanks for the help fella's. I allready have a 7" dual diaphram booster, dual m/c without residual built in, a 2 lb and a 10 lb residual valve and a GM style combination/proportioning valve. I think I have a better understanding of what I need to do with all this stuff now. The diagrahm Randy posted and some other info it led me to helped a bunch. I guess we'll see when I try to Stop!