Disc brakes locked

Mopar Marv said
One quick question. Are you still using a drum brake proportioning valve?

You Have to swap out the valve when you change from drum to disk brakes!!!!

The drum brake valve holds pressure on the front brakes so that they start grabbing before the rear brakes. Other wise you end up with a ride that spins you out every time you hammer the brake pedal hard.

I had the exact same issue the O.P. is describing when I did my first drum to disk swap like thirty years ago.

Geezuz. NOT TRUE. The drum brake "device" is NOT a prop valve. It is nothing more than a sliding piston which activates the warning light switch in case of pressure difference between front / rear, indicating a leak in one end.

The drum brake device would have nothing to do with the front brakes locked.

THIS is what drum brake cars have......a hydraulic piston operated switch