Jim, I'm not saying that will fix all your problems but it is a place to
start.

All Vanagon cooling systems use the top of the tank as the collection
point for air and then it gets pushed out through the cap over time. The
water pump is supposed to draw coolant from the bottom of the tank. The
way it is now the waterpump is drawing from the top of your tank, where
any air would be, the opposite of how VW intended.

Finally, the vendor confusion is understandable. There are 2 very
different tank/hose configuration used in our diesel vans. When people
with the earlier 81/82 system need a new tank they commonly use the
86-91 waterboxer tank since it matches up better with their 81/82 hoses
and slight mods. Not so for people with the rarer 83 and newer diesel
vans. Those people can use the 83-85 waterboxer tank and the 83+ diesel
hoses fit it fine, without mods. Most vendors will have dealt with the
more common 81/82 situation and thus may steer an 83 customer the wrong
way without knowing all the differences.

Mark

Jim Felder wrote:
> Glad to hear it, mark! I'd rather it be that than just about anything else.
> Thanks for catching.
>
> Jim
>
> On Thu, Dec 10, 2015 at 2:49 PM vw_van_fan_Mark <madvws@cox.net> wrote:
>
>> Jim, you have the wrong tank, I can see that in your photo. You need the
>> other waterboxer tank (1.9) 84-85. It would work with that new lower
>> hose you thought was wrong. That new hose was actually right and didn't
>> need the mod you made to it......