I finally got a replacement brake master cylinder this week and I went to swap it today. Turns out though, that my replacement one has a seriously large (like 14-16mm diameter) fitting on the bottom of the cylinder. My old one lacks this, and so does the one on my friends GXL. Did I get shipped an incorrect unit, like an ABS one maybe? If so, does someone have a spare sensor (or whatever is supposed to go there) I could buy to plug this with, since I'm not planning on paying a dealer restock fee by taking it back, and I had my friend drive me all over town trying to find a bolt or brass fitting large enough to plug it. Thanks for any help.

 

If the dealership gave you the wrong part, they won't chage a restock fee. That's bad business.

Exchange it for the right one.