As David says, there is such a thing, or a similar thing in the 21.
wasserboxer. On top of the thermostat, breather valve which connects
t stat housing to purge "ring" that runs around engine.

You can run engine with that valve open to be sure of air purge. Its
not a case of coolant pressure -> atmospheric press, but rather
higher to lower.

alistair

On 22-Apr-10, at 5:19 PM, Tom Hargrave wrote:

I understand but the Mercedes bleed line is under coolant pressure so it
stays open all the time and it actually tees into the bleed line that
comes
off the radiator.

The two work together to keep the cooling system gas free unless you
have
such a head gasket leak that the small diameter tube can't keep up.
But by
then you shouldn't be driving the car anyway.

I wonder if the same setup can be installed in a vanagon?

Tom
www.kegkits.com

-----Original Message-----
From: David Beierl [mailto:dbeierl@gmail.com] On Behalf Of David Beierl
Sent: Thursday, April 22, 2010 6:49 PM
To: Tom Hargrave
Cc: vanagon@GERRY.VANAGON.COM
Subject: Re: Water Cooler System Design Flaw Workaround?

At 06:49 PM 4/22/2010, Tom Hargrave wrote:
> Mercedes did just this in their 80's V8 SLs. They ran a small purge
> line from on top of the thermostat line over to the surge tank. The
> solution works really well.

So does the 2.1l Vanagon setup, except that it has a valve to open it
while
bleeding and then close.

Yrs,
D