If the original poster means he's using an open end wrench, that's not
the tool to use ..and they will round off, not 'warp' the nut.
If the poster means the nut grabs and twists the line using a tubing nut
wrench ....that could be warping of the nut ...though in 5,000 undoings
of such nuts I have never seen that happen.

  The correct tool is a 5 sided open end wrench, called a tubing nut
wrench inmy world.

if the line is rusted to the nut, then yes, turning the nut will twist
the line.
Don't let that happen.

The ability to clearly express in written words is rapidly fading away,
or so it appears.

On 7/9/2013 11:04 AM, Stuart MacMillan wrote:
> Sears sells this flare nut wrench, but only in a kit of four for about $35.  Worked great and well worth it not to ruin the fitting.  I could not find it anywhere else separately.  http://www.sears.com/search=flare+nut+wrench+set?vName=Tools&cName=Wrenches&autoRedirect=true&viewItems=50&redirectType=CAT_REC_PRED
>
> Stuart
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Mike Riley
> Sent: Tuesday, July 09, 2013 9:07 AM
> To: vanagon@GERRY.VANAGON.COM
> Subject: 11mm brake line wrench
>
> anybody have a recommendation for a good system to loosen the 11mm fittings on brake lines? Been through the usual wrenches and always wind up with vice grips.
> The wrenches always seem to warp the  nuts.
> mike
>