I just completed swap of power disc brakes from a 76 to my 65. The problem is my calipers are too tight. When the truck is cool and not running it will roll fine under manual power. As soon as I start my truck the calipers tighten to the point that it doesn't roll freely. I have new master cylinder, calipers and lines. I reused portioning valve and the brake booster. In the current condition the brakes heat up when I drive to the point of locking up. Anyone?

 

Test the check valve. If it's okay, replace the booster... somehow it's getting a false vacuum signal as if the brakes are being actuated when it is not.

 

Is the check valve the part at the end of the hose that goes into the booster?