[s-cars] soft break pedal

[Nicholas]

My '92 sedan has had a soft-ish brake pedal since I've owned it... and
I've gotten used to it. I've also gotten used to the brake light being
on for the first few minutes and then going off (always thought it was
a delayed e-brake signal). But now it seems like it's staying on
longer and coming on intermittently while driving (had one drive where
it was on the whole time!). I've had a couple of folks suggest the
brake bomb but I've contacted Dave Kase and he suggested my issue is
actually on the "brake fluid side". So today I bled the front brakes
(not using power: just a hose, jar and dot 4 fluid) and ran out of
light before I could get to the rears. There was a good amount of air
bubbles that I purged from both sides. I went for a quick drive after
getting things buttoned up and noticed absolutely no difference in
pedal feel or intermittent light activation. So it seems there is some
air getting into the fluid side but how?  I can't figure out why it
doesn't seem to get worse/better???  And how, if related, would that
affect my brake warning light?

Suggestions appreciated!

-Nick

P.S. I actually have this car up for sale right now and want to make
sure it's safe before handing over keys:
http://www.motorgeek.com/viewtopic.php?f=4&t=43823

P.P.S. I'm Bently-free.