The OEM dealer boots are EDPM rubber (at least they used to be) and worth
the money.  My '84's boots were still good when I sold it in 2006 after 200k
miles, and I replace the joints once (not the boots). Lucky for me, my "new"
'85 still has the original boots and they are fine after 145K.

I don't know what some of the aftermarket boots are made of, and there is
probably no way to tell for sure.

It's too bad no one sells a split boot anymore, at least with those you can
replace them easily.  You might call these guys to see if they have anything
though:
http://www.dormanproducts.com/c-255-cv-joint-boot-kits-solvent-welded-split-
boot.aspx

Or look for used OEM boots!

Stuart

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Craig Cowan
Sent: Friday, March 22, 2013 8:30 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Cv boots cracking

Because it doesn't need to be serviced at this interval! I just rebuilt some
with a friend that were original to the bus and have never been serviced (
he's the original owner). 140,000 miles and 26 years of use, and the boots
we took off were fine!
So why do mine suck?

-craig