Rear Diff leak

I have a 98 dodge ram 2500 4x4 diesel. Probably too much info but there you go. I had a leak in the rear diff and promptly took it to Brake Master as recommended. They fixed the leak but said it was caused due to blockage to the bleed line(if thats what you call that hose coming off the rear diff). Well that lasted a week before it started to leak again. I took it in and they fixed it again free of charge. One day later it is leaking again. They used silicon and lots of it because it is leaking out everywhere. But yet it leaks again from the bottom. Is there a gasket that they should be using in conjunction with the silicon, resurface the diff plate or diff body, or just fix it again. Any ideas of what to do?

I’d call a local auto parts store and find out if they list a gasket for the differential cover plate. If no gasket, then perhaps cover is warped (perhaps due to improper bolt tightening), one of the surfaces was marred or damaged, or silicone was improperly applied. Thoroughly clean both surfaces and apply a thin film of silicone to both surfaces and completely around the bolt holes. Bolts should be tightened a little at a time and tightening the opposite bolt (as in replacing wheel lugs). If there is a slight warp or marring of the surfaces, then the silicone should be allowed to cure before gear grease is added to the differential.