steering leak

Hi,
we've got an old disco as a site vehicle , today someone was driving when they had a pop and steering fluid was dumped on the floor. It is coming from what looks like a breather hole on top of the fluid side of the steering box, and will empty itself in minuets, any ideas or is it a recon box???? cheers phil....

its bleed nipple 11mm or 7/16 turn it to close

Thanks for the reply, if there was a blead nipple there i would tighten it, it seems to have disapered. proberbly what the pop was.
cheers phil..........

just put a plug or bolt in it isnt really needed

Just checked our disco and the bleed nipple is on the very top of the steering box and intact. the hole i'm talking about is lower down on the fan side and sits about 1 cm away from a metal oil pipe feed/entry point, it doesent look to be threaded thats why i thought it was a breather hole. thanks phil.....