Thanks Jay and others for the advice.  I did go ahead and bleed the system last
night.  Very simple to do.  Didn't know there was a groove in the bolt to
facilitate this without fully removing the bolt but it was no problem.
However, it would seem that my problem has now made itself more evident.  After
bleeding, I took it out for a drive and the temp shot up pretty quick and the
light even came on.  I stopped the van, added more water to the surge tank and
then proceded.  The light went off but the temp stayed high until about 30
seconds later when the temp plunged downward.  At this point it became pretty
obvious that I've got a faulty thermostat.  Unfortunately, either as a result
of the high temps or preasure caused by the thermostat, I now have a new
plastic part leak.  What fun!  It's that wondefully accessable distribution
pipe at the front of the engine on the passenger side.  So I've parked Van and
this problem will just have to wait until I do all the other engine work I'm
planning to do sometime in the next couple months.  Thanks for the help.  This
list has come through for me once again.

Jeff