Jaap Nauta wrote:
> I agree that level can go down due to air in the system, but can it come
> up again completely when cooling down? I would guess you would find the
> level staying too low.

Yes indeed the level will come back up.  That's the same reason that,
when filling the coolant system, you rev the engine to add coolant and
do NOT drop the RPM while the expansion tank cap is off.  Else you'll
get a coolant bath.  With air in the system (cap on), you can operate
the throttle by hand and watch the coolant level go down then, when you
let off the throttle, the level will come back up.

Mike