brakes dragging

[SkidmoreGarage]

I would think that the front residual pressure valve (inside the proportioning valve) would fail open and not closed. This would lead me to believe that you may have air in the lines, especially if you only added fluid and didn't bleed the lines.

Once the air gets hot, it expands and can push the calipers out. You would think that excess pressure would bleed off back into the MC through the residual pressure valve (but that may be a product of where the air is and how much), but a brake bleed should be an easy place to start.