Michael,
Make sure your mechanic purged the cooling system from air according to the
Bentley manual with the front end jacked up to the proper height. No other
method (though many are used), has any engineering creditability. It is
likely some of these methods do not get all the air out and folks just think
everything is fine.  If your mechanic purged the system properly, either you
have a slight head leak or a hose clamp is loose. Sorry to say its most
likely if you see no fluid leaks, its has to be the head.  Its the only
place air can get pushed into a pressurized system.  Make sure your overflow
bottle has fluid up to the mark so the cooling tank cannot such any air back
in.

Hope that helps.

Doug in CA

----- Original Message -----
From: "MICHAEL POPE" <raskayamon@MSN.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Friday, March 26, 2004 7:57 PM
Subject: 89 Westy

The van is not going to Back from the Dead- Bob Goodwin 30 years exp.
factory trained is working on her. He says there is nothing wrong with her.
He is the one who replaced the head gaskets and put NEW heads on last May. I
have driven about 18,000 miles since then- entire cooling system has been
replaced including radiator. Still getting air. he is not driving the van on
the freeway which is the only place that I have a problem. It was actually
fixed for awhile but have been battling this problem for a couple of months
now. Thought the problems came back cause of  a leaky radiator, but replaced
it & still getting air / only on extended high speed  over 60 for 30 minutes
or so especially if in the mountains. But NOT OVERHEATING, if it were the
head or head gasket wouldn't it overheat.  Any cooling gurus out there with
any insight?

Michael