Originally Posted by Huaco
It is a brass compression. Got a picture of the o ring method?
pretty simple, get a bag of silicon orings from McMaster Carr. Replace the compression ring with 1 or 2 orings, hand turn the compression nut till tight, turn 1/4 to 1/2 more.
I think this is the one, number 111 for 1/2 o.d.(works on 5/8 od also). It is the same as the oring from a keg disconnect. http://www.mcmaster.com/#9396K24
I think I also order 109 back in the day for 3/8 tubing.
here is another useful list of oringshttp://www.homebrewtalk.com/f11/mcmaster-keg-o-ring-list-233086/