1989 to 1970 Master cylinder swap question?

[Steelie73]

I have a 1970 chevy pickup and I want to put disc brakes on the front. I pulled the master cylinder/booster and proprtioning valve off a 1989 suburban that my buddy was throwing away. Can I use this combination in my truck. The suburban had front discs and rear drums. If I wanted to change to all discs would I just have to change the proportioning valve.

[raycow]

Originally Posted by Steelie73

If I wanted to change to all discs would I just have to change the proportioning valve.

It depends where the residual pressure valve is located for the rear wheel side of the system. That has to be removed for discs or else the pads will drag on the rotor when the pedal is released.

Ray