1994 Mercedes E320 wagon brake master cylinder nut removal issues - PeachParts Mercedes-Benz Forum

dmorgan · #1 12-02-2021, 01:12 PM

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.

Sugar Bear · #2 12-02-2021, 02:37 PM

Post a picture if possible as I don't have that model to look at. 1/2" is actually better than 13mm if you can get the 1/2" all the way on the nut. 1/2" is .012" smaller than 13mm. Six point is always better than twelve point when working with nuts that may round off.

Do the exposed threads on the stud look damaged?

Good luck!!!

dmorgan · #3 12-02-2021, 05:30 PM

Sugar Bear thank you for your post above. Much appreciated it. Enclosed are the pictures of the Brake Master Cyclinder. It is sure a tight location to remove the darn nut. I tried different sockets, all six point, 1/2 inch, 13mm, 12mm, 7/16 inch. In addition, open end wrench 1/2 inch, 13mm, 7/16 inch, 12mm, none of them all will not get in the nut clearly and tight fit. I am practically stumped. Any ideas out there?

dmorgan · #4 12-02-2021, 05:33 PM

I forgot to add that it appears that the thread with the nut on is ok., no damage from what I can tell

dmorgan · #5 12-02-2021, 05:36 PM

Is there some kind of crescent type wrench that has enclosed hole like an open end wrench that has a roll like dial that tightens the nut. I believe it is call like a ratchet wrench or something like that.

dmorgan · #6 12-02-2021, 05:37 PM

I apologize for the fuzzy pictures.

dmorgan · #7 12-02-2021, 06:51 PM

I saw this particular offset metric box end set. What do you guys/gals think?

Sugar Bear · #8 12-02-2021, 09:36 PM

It looks like the bracket has to come off first. Are the nuts holding the bracket in place?

dmorgan · #9 12-02-2021, 10:02 PM

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?

dmorgan · #10 12-02-2021, 10:02 PM

What nuts are holding the bracket?

dmorgan · #11 12-02-2021, 10:04 PM

and where the bracket is located that the nuts supposed to hold the nuts?

dmorgan · #12 12-02-2021, 10:04 PM

hold the bracket?

dmorgan · #13 12-02-2021, 10:14 PM

If this turns out to be a bracket behind the nut, then why there is no bracket behind the nut that I removed easily on the top right entry hole (facing me) on the brake master cylinder?