Relax boy... the cap is new, still, others are right...check this one,
just blow air in it....anyway, you still have the other one...

Like i said, here is how anyone can diagnose a probleme like that.

-Check the front rad, is it hot? when the temp gage show HOT, if not, go
under the van and check those 2 big cooling line, are they hot?

Like that, you make your way toward the back of the van... this can tell
you where the problem can be...

you may have a cloged rad, so stuff is moving around when driving..

Of course, if the fans rad is cooked, it make sense that wile comming back
from a freeway ride, when the engine is really hot,it is then that the
problem occur.....

Keep me up t date.......pfffffffff, am in vacation and you still buging
me, he he he...

By the way, yes, Fort De Soto is a beautiful camping place in FL...

Cheers, Ben
www.benplace.com