I purchased a disc brake conversion kit for my 68. It actually had disc brakes originally, but some bonehead took out the whole system before I got it. I put the system in and the front brakes work fine, but I am not getting pressure to the rears. The kit included master, booster, calipers, and proportioning valve. I got another master, thinking I got a defective one in the kit, but still no pressure to the back. Any suggestions would be appreciated. Could it be the proportioning valve?

 

It could be that the valve isn't centered, does the brake warning light on the dash work/come on?

Go to test combination/proportioning valve in this link and it says what to do if it is the valve.

http://www.classicperform.com/TechBo...oubleshoot.htm

 

Thanks blue, this will help. Hopefully it will work.