Tobias,

Air in the cooling system will cause problems regardless of the vehicle and
air blocking coolant flow, not lack of coolant is what causes most engines
to overheat. The water pump can't overcome bubble in the upper radiator hose
when you stop and your temperature spikes.

But several European cars have what I consider a flaw in the cooling system
- the "flaw" is that the designers route the upper radiator hose so high or
mount the radiator so low that the system can't self purge. This "flaw"
requires you to purge the system after any coolant service. For example, you
WILL DESTROY THE ENGINE in some 3 series BMWs if you don't follow the
correct bleeding procedure to purge the air bubble out of the upper radiator
hose after performing a coolant service. I'm sure the if the vanagon has the
same flaw then it has a similar purge procedure and someone else more
knowledgeable than me of vanagon cooling systems can give you instructions.

No reflection on your abilities but this is a good example of home mechanics
or pro mechanics without the right experience doing more harm than good
because they know just enough about what they are working on to get into
trouble. The mechanic would change the coolant, not properly purge the
system and then the mechanic or his customer would pay the consequences
later.

Tom
www.kegkits.com

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM] On Behalf Of
Tobias Gogolin
Sent: Wednesday, April 21, 2010 11:56 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Water Cooler System Design Flaw Workaround?

I suppose most of us are aware that if for whatever reason there is air in
the cooling system of a Vanagon (T3?) it will overheat because the system
gets 'air locked'. That means the coolant cant flow through the radiator
because it would have to push air down in the return path an there is
obviously not enough pressure to do that...
I'm suspecting there could be some solution, one would be to put the
radiator down where the spare tire is and eliminate the potential vapor
lock, or... what else ?

Thanks!

Tobias