You are so, absolutely right.  A local fellow seeked advice on rebuilding
his type 4 motor, I pointed him in the right direction, and told him
specifically not to put rtv on the push rod tube seals............a month
later, he asks me to help him with a tune up.  Guess what I find...Orange
rtv everywhere..............thick.  Some folks just will not listen.

Adam P
81  Westy "The Brick "
70 Single Cab "Whitey"
74 Beetle "Ol Yeller"
73 Transporter (STILL at paint shop)
1988 Vanagon Wolfsburg
1976 Transporter (New CA bus)
1974 412 "Goldmember"
Used Vanagon Parts for sale (mostly aircooled)
----- Original Message -----
From: "G.M.Bulley" <gmbulley@BULLEY-HEWLETT.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Tuesday, January 14, 2003 12:20 PM
Subject: O-Rings, was: rebuilder blames coolant for failure under warranty

> I'm not sure if you guys are joking about putting sealant on o-rings,
> but if any of you are, I'd strongly urge you to read up on how o-rings
> work. They are perfect in their simplicity, and rely completely on
> absolute cleanliness, and absolutely no other material in their sealing
> zone.
>
> I'd be up their with Bill Gates if I had a dollar for every type-4 I
> found with leaking push-rod tubes seals, only to find RTV or 'high-tach'
> sealant on the o-ring seals. Since the type 4 motor gets wider as it
> heats up, the heads must be able to move in and out, and the o-ring
> bores (for the pushrods) are about 2mm wider than they need to be (at
> rest) so the rings can roll as the heads move. Clog up that 2mm with
> goop, and they won't roll, and they leak within 50k miles.
>
> The pressure of oil behind an o-ring causes it to seal better as the
> curve of the ring is flattened under the pressure. If the oil can't get
> behind the curve of the ring (again because of RTV) you get leaks.
>
> Were you joking?
>
> Bringing ideas to life,
> G. Matthew Bulley
> Bulley-Hewlett
> www.bulley-hewlett.com
> AIM = IExplain4u
> +1.919.658.1278
> "Fax mentis incendium gloria culpum"
>