Date: Tue, 10 Sep 2002 22:03:48 -0700
Reply-To: Claudio Cella <claudiocella@SHAW.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Claudio Cella <claudiocella@SHAW.CA>
Subject: Re: Summary: Re: How hard is it to remove exhaust?
Content-type: text/plain; charset=iso-8859-1
An absolute yes on that Ben, the flanges MUST be there for support. My
initial "chisel and hammer" comment was made with the thought that the
exhaust system would be intact without any part (including flanges) removed.
Without the flange support it wouldn't really matter at which angle one
would apply chisel to nut/stud it would surely bend or snap off.
I sure like some of the responses posted pertaining to this topic. One of
those
"club hammers" has just been added to my tool wish list. Thanks folks !!
Claudio Cella
87 Vanagaon GL
90 Jetta TD
----- Original Message -----
From: "Ben McCafferty" <ben@kbmc.net>
To: "Claudio Cella" <claudiocella@shaw.ca>; <vanagon@GERRY.VANAGON.COM>
Sent: Tuesday, September 10, 2002 6:42 AM
Subject: Re: Summary: Re: How hard is it to remove exhaust?
> If the flanges aren't cut away, yes, you can do this. But if they are,
the
> head does not support the nut, because it's floating on the stud. This
note
> could be added to my list below.
> tx,
> bmc :)
> "Faith will move mountains, but you'd better bring a shovel...."
>
>
> > In regards to using a hammer and a chisel - the hammer and chisel
method
> > would be used parallel with the stud (at least as close as possible to
this
> > position given the amount of room), therefore hitting the nut on it's
top
> > surface with the cylinder head acting as a support. Using a hammer and
> > chisel perpendicular to the stud can also work but i agree that there is
> > more of a chance of something going wrong.
> >
> > Claudio Cella
> > 87 Vanagon GL
> > 90 Jetta TD
> > ----- Original Message -----
> > From: "Ben McCafferty" <ben@KBMC.NET>
> > To: <vanagon@GERRY.VANAGON.COM>
> > Sent: Monday, September 09, 2002 8:25 AM
> > Subject: Summary: Re: How hard is it to remove exhaust?
> >
> >
> >> You've gotten some good advice. Let me summarize all this in a way
that
> >> (hopefully) makes some sense.
> >> --Start by squirting the exhaust nuts (8 of them) with penetrating oil
> > every
> >> day for two weeks.
> >>
> >> --On D-day, if you have the luxury, remove the engine.
> >>
> >> --GENTLY try to remove each nut with a wrench or socket. If there is
any
> >> significant resistance, STOP.
> >>
> >> --Cut away the old exhaust (assuming you're replacing it) to give extra
> > room
> >> to work. Ideally, cut away the flanges too, so you have an exposed
stud
> > and
> >> nut.
> >>
> >> --Try to borrow a nut splitter and split the remaining nuts. I don't
> > agree
> >> with using a hammer and chisel for this part, as it's easy to
bend/break a
> >> stud.
> >>
> >> --If you can't get to a nut to split it, you will have to try to remove
it
> >> with heat. In this case, it is likely that you will back the stud out
of
> >> the head. Using a propane torch, heat the head around the stud, not
the
> >> stud itself. You will need to apply heat for 5 minutes or so. Try to
> > back
> >> out the stud a little. If it comes out, great. If not, try tightening
it
> >> back in a little. Go back and forth like this, still applying heat to
the
> >> head only. Eventually it will either come out or you will pull the
> > threads
> >> out of the head with the stud. If at any point the stud starts to feel
> >> "soft", you're about to break it off. The way to notice this is when
you
> >> are turning the wrench, and the stud tip is turning, but the base is
not.
> >> This is bad. Stop, go get something to drink, call a friend, whatever.
> > Try
> >> to get some experienced hands in there to help out. If you shear a
stud,
> >> you will probably have to remove the head and take it to a machine
shop,
> >> where they can accurately drill the old stud, and re-thread the hole.
> >> You can still use penetrating oil, but remember that it's flammable, so
> > use
> >> it between torch sessions, not during! :)
> >>
> >> --If you stripped the threads out of the head, use a Heli-Coil kit to
> >> replace the threads. These are expensive, but worth every penny. The
one
> >> you need is M8x1.25.
> >>
> >> --If you sheared the stud, you can take the head to a machine shop, or
try
> >> your hand at drilling the stud. You will need a drill that has a low
RPM
> >> setting, and a bit suitable for mild steel. Center punch the stud,
then
> > use
> >> a small drill bit to begin drilling straight into the center of the
stud.
> >> When drilling steel, you should see two shavings making two corkscrews
of
> >> metal, coming up out of the hole. If you have lots of little shavings,
> > you
> >> are drilling too fast, and you're polising (dulling) your bit. It's
very
> >> easy to break off the drill bit, so be careful to support the drill.
Once
> >> you've drilled in a ways, move to the next larger size drill bit.
> > Continue
> >> this process until you have drilled out the center of the stud, leaving
> > just
> >> the threads. At this point, you can try using an EZ-out to pull the
> > threads
> >> out. Here again, do not use too much force with the EZ-out. If you
break
> >> it off, you are guaranteed a visit to the machine shop, because the
EZ-out
> >> is made of a very hard alloy, and will require a carbide burr to drill
> > out.
> >> If the threads come out, great, you're ready for the new stud. If not,
I
> >> would go ahead and drill out the threads in preparation for a heli-coil
> >> insert. You've already done most of the work, so just use the
heli-coil
> >> bit, then tap the hole and insert it.
> >>
> >> --For the studs you didn't have to remove (if any), run the appropriate
> > die
> >> (M8x1.25) down the stud a few times to clean up the threads. Be
careful
> > not
> >> to cross-thread the die.
> >>
> >> --When putting it all back together, use a good quality anti-seize
> > compound
> >> (I use permatex, aluminum based) on EVERYTHING. Copper-based is great,
I
> >> just can't ever seem to find it. This includes the 8 exhaust
studs/nuts,
> >> plus the j-tube bolts/nuts, and the muffler and tailpipe bolts/nuts. I
> > also
> >> have a rule of thumb that says anytime I remove an exhaust bolt/nut for
> > any
> >> reason, I put new anti-seize on it as well.
> >>
> >> --Use a torque wrench on everything, it's easy to over-tighten/strip
these
> >> parts.
> >>
> >> --Hope this helps, best of luck. Know that many knuckles have gone
before
> >> you, and we can all empathize with you.
> >> tx,
> >> bmc :)
> >>
> >> "Faith will move mountains, but you'd better bring a shovel...."
> >>
> >
>
>
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