removing brake-line flare nuts

[Dave Diamond]

Replacing braided brake line after my mishap at Chuckwalla, I'm having trouble removing the 11mm flare nut attaching the hard line to the flexible line. I know these are usually hard. I'm using a good quality craftsman flare nut wrench; put on lots of penetrant; used heat (carefully) on the fitting when the penetrant didn't work. No luck. I've rounded off the nut on a couple of corners already.

I've NEVER actually removed one of these intact. I once tried to replace the original lines on my boxster with stainless steel ones, but never got the old ones off (so I still have a set for a 986 boxster if anyone needs them!).

Anybody found a way to do this? Vice grips look like the next step, but I hate to completely ruin the nut -- might make it hard to get it back on.

Thanks.