On my 1994 Mercedes E320 wagon, I am trying to remove the old master brake cylinder. The problem is one of the two nuts that holds the master brake cylinder would not turn to come off lower left facing me. I feared that the nut is stripped. I used a 1/2 inch socket and there is not enough room, too confining and not enough space to use a socket ratchet. When using the 1/2 inch socket, I felt no tightness and a little loose on the socket. The nut is 13mm same as 1/2 inch. I even use the open end wrench with 12 point and still not a tight fit. I used the same open end wrench to remove the top right nut facing me on the master brake cylinder and the nut was removed just fine and no problem. the nut was small in depth size due to that darn little black box that is inside the bolt, leaving little depth so that the wrench 13mm or 1/2 inch does not go all the way through the nut enclosure. Unfortunately that little black box is on the bolt that use the same nut that holds the master brake cylinder.

I did some research on how to remove the nut without stripping it. What would be the best course of action to remove that darn nut without stripping? flare nut wrench? extractor nut wrench? I found some information on amazon: Amazon.com : Extractor Wrench 12 pt 13mm

What about getting a Offset Metric Box End Wrench even though the depth of the nut would not be deep enough for that offset metric box end wrench to come through.

Anyone out there had some experience in removing that nut? Any comments, feedback or advice is greatly appreciated. Thanks to all for reading this post.