Check the blue pointy radiator cap that sits on the .  Volkscafe has the cap
for under $7.
http://volkscafe.com/main.jsp?pa=p&p=1961408540&pct=1232111170&ct=663075209

My symptoms were: Water was overflowing out of the overflow reservoir.  When
the van cooled down, the water was sucked back into the engine.  I checked
the radiatior cap and it wouldn't hold ANY pressure.  Yes, I also saw
bubbles coming from the small hose as well.  I assume it was air in the
system caused by some of the fluid leaking during previous driving.
Replacing the cap solved the problem.

Tim

> -----Original Message-----
> From: Dennis Haynes [mailto:dhaynes@OPTONLINE.NET]
> Sent: Sunday, July 11, 2004 8:15 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Bubbles, bubbles...
>
>
> The o-rings at the top of the cylinder do very little to keep combustion
> gasses out of the cooling system. The real failure is the gasket between
> the cylinder and the head. The engine at some point may have over heated
> or for some other reason the cylinder studs lost their preload,
> (tension, stretch). Re-torqing the heads may help, but as you suggested,
> a passage may be burned in. A leak down test may show if one or both
> heads need attention. A head gasket job is in order.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
> Of zolo
> Sent: Sunday, July 11, 2004 1:30 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Bubbles, bubbles...
>
> Hi guys,
> This morning a friend woke me up to check his car.  His water was
> overflowing from the overflow tank.  When it cooled down, all the water
> has been sucked back to the engine and still some were missing.  I
> proceeded to bleed the system but I knew something must be amiss.  In
> the process I noticed that bubbles were constantly coming out of the top
> hose of the pressure tank and I traced it back to the right cylinder
> head direction.
> The question is; what is this phenomenon and what is the remedy?
> Zoltan
> My guess is, that the top O ring of one of the cylinders of the right
> side head is leaking through because the head is not flush with the
> cylinder and now it is probably already created a passage that won't be
> closing with the retightening of the head.  The car is 13 years old.
> Yes, it is a '91 model which sound like 2005 to some of us, but it is an
> older car now and all the syntetic gaskets have aged in it.  In this
> case the engine would need a whole gasket change in my opinion.
>
>