I had that problem that was caused by a front brake line that had collapsed internally and would only allow fluid to go one way.
The brakes did not drag until you stepped on them for the first time on a drive, so it seemed normal pulling out of the driveway, until I came to a stop.
Totally locked up and nearly caught fire.
new line. Problem solved.
If your is dragging both front and rear, they might not be related.
I've had rear drum brakes drag from bad springs.
the easy way to check spring health: Pick it up and drop the spring on the ground. If it make a "tink" sound, it's probably bad. A good spring will just plop and not make any noise.