I'd vote for new brake fluid. A couple of bottles is plenty.

Be aware the master cylinder is split (I believe front to rear so if you have a caliper failure, you still have have half your brakes - nice design). What that means is when you start bleeding the calipers and the master cylinder fluid drops, you'll see that only part of the master cylinder is draining. You'll have to add brake fluid almost to the very top of the master cylinder to get the fluid to spill over the internal partition (that does the front / rear proportioning).

Hope that makes sense.

__________________
~shell
As of 2/2010:
2001 CLK55 0o\=*=/o0
13.6 @ 106mph
10K mi
1984 300SD
260K mi and going and going...
97 S600
46K miles
1991 Sentra SE-R (extremely dorked with)
www.se-r.net