So, I've done about everything I thought I should to make my '91 camper
as reliable as it could be, including lots of cooling system fixes.
Just replaced all coolant hoses, since so many think that should be
done.

First really cold weather of the winter last week.  Started up the van,
only to see a coolant drip underneath.  Methinks, well, a loose clamp on
a hose, not tightened adequately.  Take off the lid, search all over for
a hose leaking.  Nada.  Continue searching, coolant drip diminishing.
Stops.

Didn't drive the van for a week.  Cold weather returned, and methinks
the van should be driven a bit.  Start it up, and it drips, then drips
more, then a larger drip, then drips from more than one place.  When the
engine was warmed up, the leak quit.

Head gaskets are leaking.  The question:  I find it difficult to think
the gaskets just all of a sudden turned loose (I'd even removed the tins
to look for evidence of leaks when I did the hoses, and saw none).
Could it be that the heads and or gaskets were already loose or
whatever, and the cold weather made them looser and so they leak?  If I
run the engine a little while, the leaks dry up, suggesting to me that
temperature plays a role -- expansion, contraction ..... .  So, could
the heads be sealed better even with the temperature difference between
normal fall temps and the quite cold temps we've had lately?  I'm just
trying to understand why this suddenly showed up, and wonder if it being
coincident with the cold weather is more than a coincidence.

How much should a fix cost?  If I need heads milled, am I better off
having a local guy mill them than buying rebuilt heads?

The engine only has 30K on a rebuild, according to paperwork I got with
the beast.

Thanks, David