Apparently reading comprehension isn't so strong with you, don't froget the qualifying "may" in there. Ntuarally, it could be a host other things, but the leaking at/around the grommet and mushy brakes are good indications that the prudent course of action on a 26yo car is to replace a cheap part to help ensure brakes are functioning at peak performance. Good luck with your reading comprehension goals in 2012.

BTW, when the master cylinder died on my old Chev Subruban back in 09, it sure made a nice bit of noise quite similar to a clunk...what are the odds?