Brake Part I.D

i recently purchased a dual reservior master cylinder setup from a member here off a 1970 cj5. attached is a pic of the parts I received. what is the small sheet metal piece with the hole in the center and the 4 spiky points? its in the picture to the left of the bracket and above the 4 bolts. where does that go?
I contacted the seller and he said it was in the master cylinder, under the cap. I assume the bolt that holds the cover on the master cylinder goes through the hole in this piece? what is the purpose of it?

 

That goes inside of the MC, to keep from crushing the cover with the bolt that holds the top on. If you pull the top of the MC you will either see where it was or will find another just like it. It also helps hold the rubber boot in place as far as verticle movement in the cover.

 

thanks mike.

on a side note, the front outlet on the master cylinder is stamped "front brakes". I know there has been a lot of discussion around here that the front port should feed the rear brakes and the rear port should feed the front brakes. i agree with this as every other vehicle is set up this way and it makes sense the front brakes should be fed by the port closest to the pedal pushrod. anyway, just thought i'd mention that the factory clearly marks the front port going to the front brakes. i'm still gonna hook it up the conventional way, but i figured i'd mention that as it is a topic of conversation that comes up rather frequently around here.

 

Im glad you figured That out it ,was just laying on the bottom when I
opened it, sorry I could not help but I feel better I sent it just in case.

Shawn