What I'm experiencing is a spongy feel at all times not just when it heats-up, so there can't be any boiling happening. And if it isn't boiling then it sounds from most of the posts that it must be a bleeding problem.
As far as bleeding, I've done it twice and there doesn't seem to be any trapped air, althought it is hard to tell because when I crack open the bleeder screws, it seems that air gets introduced into the discharge tube as the fluid is going out. I bought one of those vaccum bleeder pumps, and it too seems to suck air through the bleeder screw threads. Any suggestions?
If DOT 5 is not inherently defective, then I'm willing to stay with it, but I got to achieve a harder pedal.