Well thought I would let everyone know that I finished with the brakes about a month ago. Waited this long to report so I could see if the result would last. Took one last shot at bleeding them. This time I attached a line level to the master cylinder and jacked the rear of the car until the M/C was a little nose down. Then bled the ABS module and the front brakes. Came out a little better, still a little soft. Next day they were better and the next better still. I would say they are now the best they have ever been. At this point I would say that the pedal is firm not hard. Problem is over the last month the firmness of the pedal varies. Don’t understand it. Sometimes it is excellent. I do know that it isn’t the rear brake adjustment as the parking brake engagement has remained the same. So if we discount the brake booster then I would say it has to be the ABS module. Not going to replace it, too expensive. Brakes still very good. Final note, rented a 2014 Ford Taurus (10,000 miles) last week and found the pedal feel about the same as the Lumina, that pedal also will go to the floor. Brakes are good enough for the winter. Next spring after the ABS module has been actuated a few times will bleed brakes again.