Sugar Bear, I think you are onto something. A Bracket just behind the nut as shown in the picture? If it is a bracket that caused the nut have less depth, how to remove the bracket without moving the nut? Does this bracket slides in between the nut and brake master cylinder entry hole? Do I push and pry the bracket using a screwdriver or a pair of pliers? Interesting and perplexing mystery here.If this is a bracket, is there some connector to pull off the bracket and remove it, thus leaving more depth/room for the nut to be easily to remove? Any thoughts out there, anybody?