That tank is specifically designed to purge bubbles from the cooling system
and replace them with coolant from the overflow tank.  It runs completely
full all the time unless it's in the process of purging air or unless the
overflow tank has run dry (or leak in the hose between tanks etc.).

david

At 12:21 PM 1/10/2001, Dave Baker wrote:
>I checked the expansion tank on my 85 Westy for the first time last week (up
>until now, I had just been checking the overflow tank).   I disconnected the
>line to the overflow tank and unscrewed the cap finding the tank was full to
>the very top.  Is this normal?  Seems to me it should only be half-full
>normally.  The engine was cold at the time.  BTW -- I have had not
>overheating problems (yet).

David Beierl - Providence, RI
  http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"