The trouble is the brake pedal still goes way down?

I had to replace the left front brake line that went from the ABS module to the brake caliper. And of course, it got air in the system. I went to bleed the front brakes and almost no fluid came out but after messing with it I finally got a good solid stream to come out of both front brake calibers. The trouble is the brake pedal still goes way down. I also bled the back ones and they were good to go with nice power and solid stream I did everything I know of even.

The car was on the rack I started it put it in 4WD and into gear and did a brake excel, brake excels on the front brake that is when I finally got a good stream with no air out of the brake calibers. I am thinking now the Master cylinder is just no holding pressure on the front brakes the pedal just won't come up to where it is supposed to. Suggestion on what to try next besides replacing the master cylinder?