Hello All,

I have completely redone my entire brake system and am having issues with my rear brakes not giving much braking and my fronts are doing all the work. I have the rear disc 80 Cadillac calipers with the e-brake.
I have adjusted them as instructed numerous times and it doesn't seem to help much.

I realized that I have two different valves in my brake system
1) the combination valve that came with my new master cylinder/booster
2) the original pressure regulator/hold out valve located in the line to the rear brakes mounted on the driver side sub-frame.

Can this be causing the lack of braking in the rear? Should I removed the original pressure regulating valve and re-pipe one single line to the rear?

IF anyone has experienced this issue can you tell me how you solved it?

 

I bought the CPP Big Brake kit for my 67 and it comes with a proportion valve and they said USE IT as it's for 4 wheel disc brakes. It's what they need. My car came with brand new brakes, drums, wheel cylinders - all brand new and they are power. I'm going to swap the booster to a smaller 8"-7" myself. But I've been told by many people that the proportional valve makes all the difference.
My 2 cents