I was under my new 95 disco this week bleeding the brakes and found a line unhooked. Its a hard black plastic line that is connected on one end to a nipple on the front axle and the other end was clipped to the firewall going up to right under the master cylinder. Any ideas to what its function is? And where it hooks up to on the top side? This is my first disco so still learning the truck..

 

It is a breather tube for the front dif. You have 3 of them, one also for the tranny and rear dif.

 

wow guess i shouldn't have jb welded that nipple huh? just kidding.. I thought that might be what it was but just wanted to make sure