--
Chas,

I've been having the same problem with the fluid backing up into the
overflow tank. Later after van cools the fluid returns to normal
level, is pulled back into system. Overheating occasionally, LED
blinking on and off while temp indicates "normal." having to top off
more often now, bubbling in the heater return line at the
recirculation tank.

On vanagon.com there is a FAQ that discusses head gasket problems.
The second type of gasket failure is described as an upper cylinder
"O" ring failure that allows the exhaust side to pressurize the
cooling system. Could be your problem. One diagnosis is to put a
pressure tester on the recirculation tank and check pressure. I
forget the parameters but if the pressure moves right on up above
normal operating pressure, something is pressurizing your cooling
system... Gasket problem, ugh....

>>Date:    Wed, 15 Aug 2001 00:27:48 EDT
>>From:    Chas Hoakanson <Candmhok@AOL.COM>
>>Subject: More stuff on Coolant boiling over

>>Need a little more help folks:
>>I posted this morning that when I got to work I noticed the coolant boiling
>>in and out of the overflow reservoir.  After work, I went out check the belts
>>and such -- all okay.  I  replenished the coolant in the overflow reservoir
>>(with some bottled water since fortunately my wife had just gone to price
>>club abd left a case of bottled water in the van) and drove home (abot 26
>>miles of mostly freeway).  Temp was fine (stayed below the LED).  However,
>>about half way home the LED started blinking and statyed blinking the rest of
>>the way home.