[Hotrodjohn71]

I changed out my rear brake shoes with a similar set to the front. It makes sense that after the brake drag, there could have been some glazing on the rear shoes.
So things have improved a little bit. Right now I have a pedal that goes down about 1 1/2 inches and then I have brakes. I could live with this but I would like to try to improve it all the same.

How necessary are these residual pressure valves that used to come in the outlet ports of factory drum brake master cylinders?

My research shows that these are not installed in any of the aftermarket Master cylinders including the one I bought. What was the purpose, and how necessary are they?