Probably not very many, but they are now all 23 or more years old, and NLA.
According to Go Westy they fail internally, destroying the transmission and
wreaking havoc with the cooling system without warning.  Not worth the risk.

http://www.gowesty.com/library_article.php?id=305

Stuart

-----Original Message-----
From: Dennis Haynes [mailto:d23haynes57@hotmail.com]
Sent: Thursday, May 22, 2014 7:56 PM
To: 'Stuart MacMillan'; vanagon@GERRY.VANAGON.COM
Subject: RE: Moving forward - with an autotranny.....

Of all the coolers out there have many have failed? I don't know either but
is probably quite rare. It does make a mess when it does happen though.

Dennis