Originally Posted by elbows
I tried dripping some Triflow on the bolt but it still won't budge. Any other suggestions?
These are Kool Stop pads on caliper brakes, for the record.
Have you tried "brute force" by holding the brake pad with a wrench and turning that nut? Another trick is to squeeze the brake lever and let the pads contact the rim - then wrench that nut off. In your case, make sure you line up the pads with the rim's braking surface before you begin.
WD-40 is probably a better penetrant, but make sure to wipe off any WD-40 or Triflow from the rim, especially the braking surface.
I assume the threads are a bit damaged from corrosion. Next time, place a drop of oil (Triflow will work) onto the threads to help resist corrosion.