abs bleeding brakes

Hello all, I've been working through some brake issues. I've got an 06 M5 with 180K miles. I was changing my discs, pads, and fluid and then started having air in my brake lines. I've gone through bleeding them (both normal and pressure) more times than I can count (about once a week for...

Well I've looked in FAQ and DIY, did not find anything. I had since couple of months and issue with brake not releasing normally (completely), but only after 45-60 seconds and a little distance done. On others cars I had, replacing the flexible lines that were obstructed from the inside cured...