99 Grand Caravan Brake Light

have a 99 grand caravan with 28,000 miles on it and now the parking brake
light on the dash is flashing on and off at selected intervals. it used to
just come on very momentarily when turning; but in the past week has become
more frequent, and stays on alot longer than usual. (before it used to just
go off after I made the turn). I pulled the rear wheels off and the parking
brake seemed to be hooked up right; the only problem I noticed is that my
passenger side wheel cylinder is bad and leaking. fluid is fine.... it is a
3.0L 6cyl.
TIA guys
Rob