[S14] Master cylinder leaking

[Silvi]

Hi,
My brake master cylinder started a serious brake oil leaking.
The leaking comes between 2 brake pipes from a small hole(See picture)
http://img210.imageshack.us/img210/6184/20120120123541.jpg

It seems that something released from this hole like plug or something, I can't find a picture of normal cylinder master to see if the is something missing.
I will be happy if someone can tell me how to solve this leaking?

Thanks :)

[DennisC]

I think there's supposed to be a little screw that's supposed to go in there to plug it.

[Silvi]

There is no screwing in the hole :( it's just hole so i guess some plug just fall from the hole.