Troy Delnicki typed:

> One other thing worth mentioning. You could put a valve at the bottom of
> the van in the drain cap of the holding tank. No pump needed, just let
> gravity do the job. How's that for a solution?
>

Great idea, and one I have already thought about. But anything that
increases the complexity of the drain, or makes it easier to be snagged
by shrubbery or bumped by a rock or branch would increase the chance of
being surprised by an empty tank. The stock cap has the profile of a
limpet, and I think I'd be happier keeping it that way.

--
Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
KG6RCR