My MJ sat on the sidelines most of the summer with fuel issues.  As I now have them resolved and it runs good as new, I hop in to drive it around when my brake pedal goes right to the floor.  My fluid is full and I dont appear to have any leaks so I have to believe that if my drums are not siezed, my seals went bad in my master cylinder.

      It seems like this would be a great time to upgrade the master cylinder to something a little more stout, rather than rebuild or replace the stock piece.  We all know what a chore it is to slow our oversized tires on the street.  Has anyone upgraded their cylinder?  Are there good aftermarket ones, or how about something bigger from a fullsize rig?