Navo:
Is your truck still staying dry? I just installed new silicone zipperless boots, inner and outer seals, wheel cylinders, and brake hoses in the front axle. Without the truck being moved at all, this morning I see something like a light oil or brake fluid dripping off the 4 bottom bolts and back of the brake plate, just like your pictures. I pulled off the right brake drum and inside the drum and brake assembly were clean and dry. I used Permatex on the inner seal and retainer, and on the spindle flange. I did not use it on the bottom kingpin retainer plate and 4 bolts. I don't think it is gear oil because the differential is low and there was not significant amount of oil in the axle housing.
Thanks,
Mike