Underneath the van there is a cap that you unscrew to empty the water tank.  I also have an
'81, but the cap is universal.

Bill in the Southwest

----- Original Message -----
From: "Johnny DeVilla" <johnny@JDEVILLA.COM>
>
> I just recently got my pump up and running by installing a aux battery.
> I very happy that this topic came up, cause this is my next chore on my
> list
> (after finding a suitable magnet for my beloved hula girl).
> Is there a easy way to drain the water tank itself?