thanks Dennis,

The tank behind the license plate is defective. I will check the expansion
tank frequently till I find a shop to replace it.

On Sun, Feb 26, 2023 at 2:26 PM Dennis Haynes <d23haynes57@hotmail.com>
wrote:

> Let's be sure to have the parts description correct. The tank with the
> pressure cap should be referred to as the pressure or expansion tank. The
> tank behind the license plate door is the expansion or recovery tank. Nany
> cars to do not have this tank or feature. For the Vanagon this was likely
> added to accommodate the extra expansion of the 'large" cooling system and
> to also add some visibility of the coolant level during normal operation.
>
> So yes the recovery tank is not needed for operation if all else is
> correct. With out this tank the pressure tank will not remain full. As the
> engine and cooling system heats up the coolant will expand and some will
> exit the pressure cap. As the coolant cools it will contract and the level
> will drop. As it contracts without the recovery tank some air will get
> drawn in. At start up that air will then compress as the coolant expands.
> Depending on the temp extremes some equilibrium will develop. If the volume
> change is excessive you may get a low coolant level on cold start
> indicating a top off may be needed.  Operating like this will leave little
> tolerance for a bad pressure cap or other fault in the cooling system.
>
> If the main pressure tank is failed that requires immediate repair.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List <vanagon@gerry.vanagon.com> On Behalf Of Dan N
> Sent: Sunday, February 26, 2023 4:28 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Overflow reservoir
>
> hi all,
>
> I understand how the coolant system works on a vanagon... but I have a
> question.
>
> If during a trip the overflow reservoir cracks and leaks out coolant. Is
> it safe to drive with a defective overflow reservoir? (the expansion
> reservoir is full)...  If not safe, what are the consequences?
>
> thank you,
>
> dan
>