Review on Dorman M83579 Brake Master Cylinder by Mike Steeg

I bought this, bled it on a workbench before installing it, then bled every corner of the car. I've seen the piston not fully return when pumping on the bench. More often this happened when inflating onto a vehicle. It seems to be stuck at a certain point on the reverse course. The pedal does not return to the end and the brake lights are on. Parking like this will drain the battery.