The v-brake brass bushing got stuck on the brake post stud.
same problem with this guy:
>(bikearlingtonforum.com/showthread.php?4700-Cantilever-Bosses) but the thread has no reply ;_;
I also found another dude with the same problem:
>(bicycles.stackexchange.com/questions/23825/how-to-remove-cantilever-brake-arm)but he deformed the brake post stud in his effort to remove the stuck brass bushing
My brake post stud is welded on, so I can't just wrench out the stud with the stuck bushing on it to fix the issue. Anyhow, I managed to jerryrig the brake to work, but I'm just annoyed that I can't replace my rear v-brake with a new set.