Date: Mon, 17 Aug 2009 17:19:48 -0700
Reply-To: neil N <musomuso@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: neil N <musomuso@GMAIL.COM>
Subject: Re: Dometic Exhaust O Ring
In-Reply-To: <c4e7c5f90908011152n2aa9ef56vbf8e7a4747fc5297@mail.gmail.com>
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On Sat, Aug 1, 2009 at 11:52 AM, neil N<musomuso@gmail.com> wrote:
> Hi all.
>
> In refitting the exhaust/intake manifold on my 182B, the exhaust O
> ring broke. Likely I should replace the ring on both the exhaust and
> inlet pipes. (there was a slight leak at this part in spite of added
> muffler cement. Pipes ok)
>
> What can I use as a replacement? Are these rings neoprene? Maybe get
> from my FLAPS?
>
So thanks to Phil Z's prompting, I checked out his suggestion of BC
Bearing Engineering LTD. They sent me to Wriason Seals:
http://www.wriason.com/contact.html
here in Vancouver. They sized up Viton O-rings for me. Fit fine.
The long story is below, but suffice it say that the rings worked. I
"safety" sealed between pipes and manifold with Hi-temp RTV once pipes
installed on manifold. Am happy that there are not leaks now.
Writeup and pics over on Samba. Hopefully this link works:
http://www.thesamba.com/vw/forum/viewtopic.php?t=370404
Otherwise most text posted below.
Neil.
Installed these on 2nd groove of each pipe. Double checked that 2nd
groove correct by measuring with calipers (not exact in pic, but you
get the idea) then compared this measurement to ridge inside manifold.
It seems the front face of O-ring seats against this ridge. Also
checked by trying O-rings on 3rd groove. It didn't seal. And my 182A
had the O-rings in what I assume was the original (unmoved by me)
position on the 2nd groove. I say this as I had read somewhere that
the 3rd groove was the correct position. I don't think it is.
Emery clothed pipes to clean up muffler cement I had applied a while
back. BAD IDEA I suspect this also removed enough metal from groove
where O-ring sits, to allow a reduction in OD of ring. This caused new
O ring on exhaust pipe to leak a hair. But, another part of the
problem was that pipe grooves didn't line up when installing the
retainer bit. i.e. exhaust pipe sat a little further out. Not damage
done by my hand! I filed end of exhaust pipe a *little* so it would
go further into manifold. This way grooves lined up. Still, the O-ring
on exhaust pipe seated further into manifold. Likely past the little
ridge where I suspect the O-ring normally pushes up against to provide
seal.
Edit: When I pulled the fridge before doing this work, I noted a hair
sized leak at pipe/manifold. This may have been due to exhaust pipe
length and issue with retainer.
Bottom line: if you need to clean up leftover muffler cement, find a
suitable chemical to do the job. And filing is a last resort. I just
couldn't see any other way in a way to make grooves line up.
I used Hi-temp RTV as a "safety" seal at pipes/manifold. (yellow
arrows pointing where in pic) System sealed fine, w/o it, but since
cocking things up a little, did this. Would likely do this regardless.
A 182A exhaust pipe is different in length (to my eye) and the grooves
are different. Slightly larger at high point. (arrows below) I figured
since I boobed up a little (see above), I would just swap in a 182A
pipe. No go. Even with some tenuous bending (shaping) of 182A pipe,
when little retainer bit installed, it would push pipe slightly OC,
thus a small leak happened. Drove me batty until I compared pipes.
Pretty sure that little difference in groove size was pooching things
up!
--
Neil Nicholson '81 VanaJetta 2.0 "Jaco"
http://tubaneil.googlepages.com/
http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines