sounds like a break in the wire to me. if you have done all you say you did. if so. ... get hold of a multimeter and check to see if there is 12-14volts at the brake switch. and if there is then there is current (electicity) there. and also check the bulb holders for about the same voltage. while putting you foot on the footbrake. if there is then check the bulbs with Ohm's for ristance should start on 1. and read 0 when you put the two multimeter wires together. and see if it does the same through the bulb connections.
if it does then check the bulb holder making sure the contacts are clean and are fully spring loaded so they make contact on the bulb. i have had that in my mini. i just taken the bulb holder apart and streched the spring.
but if that is not then there really is a wire broken somewhere. and that is hard to find on a car unless you are very good with electrics like me. :D i love electrics and wiring. :D
good luck and i hope this helps. :) email me if you have done it. at holygit@gmail.com
miniman andy @ TMF (the mini forum
June 2008