In a message dated 2/17/05 10:53:10 PM, donalds1@VERIZON.NET writes:

<< replace the pressure cap

Boston Bob

the night tripper >>

Sound advice.  Look to the simple things first; no need to get esoteric until
it is necessary.  In 16 years, four Vanagons and who knows how many miles,
I've had two boil-overs with the refill tank puking coolant.  Both times it
happened after running hard then stopping with the engine idling.  Both times it
was caused by a piece of foreign material preventing one of the check valves in
the pressure cap from closing.  Once it was a pine tree needle and the other
time, a minute piece of the cardboard liner from an antifreeze bottle cap.

George