Andrew,
I myself spent 1 year chasing cooling system problems replacing most parts,
redoing it and thinking
it would never work.
You don't tighten spring type clamps. You tighten only ones that can be
tightened like band clamps.
The clamps may be tight enough for coolant not to leak but air can still get
in. The leaking coolant system works like vacuum when there is air inside,
drawing more air inside.
Having myself experienced most if not all of the cooling system problems and
fixing it, i am trying to save someone time and money avoiding unnecessary
work.

Andrew Fox wrote:

> >tighten all tubing clamps,
> How do you tighten the blue spring type clamps on the vangaon?
>
> check for leaks.
> If I had a big enough leak I would be loosing coolant.  If i had a tiny
> leak I probably would not have been able to see it on a hose.  I have
> visually inspected most of the cooling system.
>
> The reason the overheating thread has been beat to death is that a lot of
> vanagon owners have overheating problems, especially this time of year as
> the weather warms up.  I hope you never experience a mysterious overheating
> problem because it really sucks and sometimes all indications seem to
> suggest that something needs to be replaced like a radiator in my case.
>
> Andrew