I'm not sure which filter catches brake debris, but when they start going it can plug a filter pretty fast.  Brakes are expensive, but much. much cheaper than a trans rebuild.  You could always sell it and advertise that it has low hours on trans work from a few years ago then say you must have "lost" the paperwork.  It seems those are the great deals I always seem to find.  (Kidding of course, I don't know how people that do those things sleep at night.)