You can replace the short line between the master cylinder and where it joins the flexible hose - just cut it off just above the nut and now you can use a six point socket on the nut, that way you won't round it off like you will with an open end wrench or even a line wrench. Once apart buy a new flex hose and a new short pipe. Bleed as usual and Job done. However if you're still on the original master, I would replace it too...they really are consumables.
Thank you, have already tried this and its absolutely solid... 2 sockets and a sore arm later lol!
Think I will get the dremel out and cut the nut off... Not a clue what to do with the engine steady bar nut of it wont loosen
I had the same problem as you. Had to resort to using a Dremel to split the nut. I rebuilt it with the Minispares one piece flexible hose C-AJJ4025COMP which was much easier to work with.