1967 Bonneville Conv Disc Brake Conversion
 

This car had 4 wheel power drums. The guy put disc brakes on the front, didnt change anything else. When I spin the front wheels they drag, I open one of the front bleeders and they spin free. I need to replace the Master cylinder and Prop valve. The master should be easy everyday part if I know which one to get. I know there is a question about rod depth but I dont know what I have until remove the existing master. So does anyone know of a bolt in Master application? The prop valve I can pick up from NPD 5 miles away, if I know which one to get. They dont list parts for the big cars but they do list a 71-73 GTO prop valve ( 2 different ones, dont know what the difference is in the 2) should work?. What is your experience?

You will need a 69/70 full size MC. As you already know there are shallow and deep pockets on the MC with long or short push rods. There may also be a difference based on the manufacturer of the booster. There are two different boosters manufacturers/styles for disk brakes.

Second, I reused my 68 drum proportioning valve. It works ok, but I think an aftermarkert adjustable proportioning valve would be better. IF you can buy new, get the 69/70 disk unit.

Rotors will be a pain and expensive. Be patient and they will show up. I bought two pairs from cyberbrakes a couple of years ago fairly cheaply. I dont see them listed on their site now however. Maybe worth calling them?

CPR has them as well, but not cheap.

Search on the 67 - up full size section. Lots of listings there on this topic.

Drum brakes don't usually have a prop valve just a juction block.

yes, a junction block. My bad. Ted, please disregard my earlier post in its entirety.