Gear lube in Brakes!!!

You may grease the bearings initially but they are lubricated by the rear end lube through the axle tubes.

The seals are inside the tube, before the bearings. If the inner seal isn't functioning, it will leak as shown. It will also wash the wheel bearing grease out, and the bearing will fail, also. A brake drum installed backwards will gain you balance, and reduce the possibility of damaging the new seal when you install the axle shaft.