I've used residual valves between the MC and proportioning valve, that's where I think they are supposed to go.

But the real question (in my mind) is did the original brake system have a residual valve? And if not then why do we need them now?
I used them because I was told I had to, but I have yet to hear a really good reason and explanation. The MC is higher than the wheel cylinders although it is not by much.

Grigg

•1951 GMC 250 in the Project Journals
•1948 Chevrolet 6400 - Detroit Diesel 4-53T - Roadranger 10 speed overdrive - 4 wheel disc brakes
•1952 Chevrolet 3800 pickup
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"First, get a clear notion of what you desire to accomplish, and then in all probability you will succeed in doing it..." -Henry Maudslay-