Originally Posted by beckybillrae
In Airstreams, the greywater tanks are bigger than the blackwater tanks. I don't know about SilverStreaks.
Good luck to you!
that's not true with older airstreams. and this is a "70's" trailer, so that could be the case here, too. don't know for sure. The first grey tanks in airstreams were very small. by today's standards, we'd think "why bother??"...but by the 70's standards, it was a rare thing to not be able to just let it run out on the ground. before the mid 70's, they had no grey tanks at all!
as far as the black tank filling...I would guess first that its a leaky toilet; both the water supply, and the flush valve, allowing water to trickle into the tank. Typically, that's the only thing that goes into a black tank, but there could be exceptions...and with an old trailer like this, who knows how some previous owner may have modified things. Its not uncommon for people to come up with systems for transferring grey water into the black tank, as it can be used to flush out the black tank when dumping. If thats the case, and there's a leaky drain valve in the system, that could explain it.