If the system lost pressure the coolant in the engine probably vaporized
and pushed out a lot of coolant, letting air in to replace it once things
cooled down.  bleeding the system is not that hard in my experience and it
doesn't have to be perfect.  It will bleed itself of remaining bubbles once
you get it mostly bled.  that is my experience with a 2.1.  I don't even
raise the front or back anymore.  As Stuart says, they've got you in a
tough spot, but you can report what happens  (good and/or bad) on the
review sites and social media.

related: what kind of luck have folks had running the vanagon with the
cooling system unpressurized?  I've done it but only for less than 10
minute drive.
Edward

On Thu, Jul 9, 2015 at 1:43 PM, Dan N <dn92610@gmail.com> wrote:

> I could be wrong but I don't think you need to bleed the system. I replaced
> twice (2 vans) that same sensor... unless the coolant is very empty... and
> even that...
>
> once I even had the big coolant hose loose and lost a big amount of
> coolant...(the one on passenger side that goes to the radiator)... I just
> put it back, tighten the clamps top up with coolant and go.
>
> just be sure, check the level on the big coolant bottle frequently and
> that's it...
>
> you could order overnight shipping for the part and replace yourself and
> drive away
>