Paul -

I had a not so serious but fustrating series of cooling system failures over
about 10000km.
3 small hoses, both long pipes, and 2 expansion tanks were replaced, along with
countless visits under the van in good clothes on the side of the road to tighten
a hose clamp. The I replaced the pressure cap. No problems for the last 2000 km!

Small 'starter' leaks at the head gasket were cured with bars stopleak, fingers
still crossed!

best o' luck
Ian

Paul Cavanaugh wrote:

> Thanks Rico!
>
> I replaced the expansion tank cap today, hoping to avoid future
> trouble until I can get this diagnosed. I am getting a lot of folks
> suggesting head or head gasket leakage. Your explanation seems very
> likely; a big thanks for the idea to take it to A RADIATOR SHOP!
> Never thought anyone can test for combustion gassis in the cooling
> system!
>
> This is my first week on Vanagon.com and I really appreciate the help!
>
> Sincerely,
> Paul Cavanaugh
> Columbus, OH
>
> >This overpressurization of the cooling system is likely caused by a failure
> >of the sealing ring at the top of the cylinder or a leak in the cylinder
> >head.  This would allow combustion gasses to enter the cooling system and
> >destroy the components you mention.  Take the van to a competent radiator
> >shop and have them test the coolant for the presence of combustion gasses in
> >the cooling system.  This happened on my 84 and it ruptured the rear heater
> >core and one of the heater hoses.
> >
> >Rico Dagastino
> >Munford, TN
>
> --
> '90 Vanagon (180k)
> '84 Vanagon (217k)
> '78 Microbus (175k)