My breaks don't go completely away, but it takes a little more distance to stop once I've been driving for a while. When I first get in and go, I have some mean brakes, but say if I've been driving for a while I have half the brakes I had at first. My brake pads only have about 6k miles on them. Could it be the fluid or what? Thanks in advance!

------------------
1986 Berlinetta, 2.8L, newly rebuilt 700R4, 3.42 Posi. 128,000 miles and counting.
Wins:
1996 Mustang
1994ish Olds Acheiva

Losses:
1999 Grand Am SE
1996ish Honda Accord (twice)
1990ish Vette (never should have been dumb enough to race a vette in the V6)