Damn Rusted Exhaust Nuts!

Rot 911 · 10-11-2003, 06:10 PM

I spent the last three hours with a dremel tool, sawzall and a chisel and so far all I have managed to do is cut off the rusted blobs that used to be the nuts on the muffler straps and the catalytic converter. I can only imagine what the heat exchanger nuts look like. UGH! My hands are aching!

masraum · 10-11-2003, 06:31 PM

You're a better man than me. My car sat for 3 weeks as I told myself that I would replace my own heat exchanger, but the car is not at the shop. I decided I didn't want to have to worry about studs broken off in the heads.

Good luck.

Hugh R · 10-11-2003, 07:00 PM

Go to your local auto parts shop and buy a "nut cracker" its like a small vise with a flat anvil on one side and a chisel on the other you torque it down and it literally splits the nut in half. Its an old American exhaust tool, and I don't know if you can fit it in where you have to go. That's my $0.02

john walker's workshop · 10-11-2003, 07:02 PM

get a torch and do the proper procedure of heating the nuts red before attempting to remove them. one at a time. if it doesn't budge, reheat and try again. dont break any studs!

jstgermaine · jstgermaine's Garage

Rusty nuts and achy hands....hmmm, looking for another 'girl of the day' candidate?

Sorry to hijack this, but the opportunity presented itself!

Superman · 10-11-2003, 10:00 PM

Listen to John. Heat them red hot. If you can't do this, take it to a muffler shop or something. They can remove and replace the nuts and then you can take it home and do your project. Don't break a stud!

dickster · 10-12-2003, 12:14 AM

go to a muffler shop, sit and have a cold beer while they sweat over it

FRED/LI · 10-12-2003, 03:50 AM

Make sure you clean all debris out of the allen head nuts. Find a long, hardened 10mm allen wrench. Cut off the 'L' end so you have a bit that will fit through the exchangers to reach the nuts. Drop this new bit into a 10mm, six sided socket and then heat the nuts cherry red. Let 'em cool, heat again and then go in and hopefully break it loose.
There's a chance that the stud will actually come out of the head. Then you can either break the nut off or install a new stud.
The hex nuts on the second side need a six sided, swivel socket, lots of heat and some luck.
A slight tightening movement at first, before trying to remove may help.
If you can fit a nut splitter in there, go for it.
Good luck

rfuerst911sc · 10-12-2003, 04:59 AM

When you do get it all apart,apply anti-seize compound on all the hardware and you won't have that problem again.

Trust Me · Trust Me's Garage

I had to use a "cold" chisel. That worked. Pain in the butt! Just lookout for the treads on the studs. Also, after this don't forget the anti seize.

JeremyD · JeremyD's Garage

I burned up a dremel doing the same thing - worth taking to a muffler shop and having them heated - not sure I would do it again if I had a choice - did take out plenty of agression on the bolts if that counts for anything. Oh one more thing - I dremeled the nuts - split them - then stuck a socket on them. With a split - much easier to get off. If you are tring to dremel through the whole bolt - that's a pain in the a$$

350HP930 · 10-12-2003, 09:32 AM

Rusty exhaust hardware is as bad as it gets in the world of turning wrenches.

In addition to the tools and methods mentioned above a good set of metric crows feet wrenches also comes in handy for getting the hex nuts off.

Do be prepared for the worse though. Despite following all the proper procedures I still had one exhaust stud break after a few turns but I am not too worried since I have the engine apart and have to do a lot of head work anyways.

I would have concidered it a major catastrophe if I was trying to put a set of headers on with the engine in the car though.

Series900 · 10-12-2003, 10:13 AM

HEAT HEAT HEAT....applyO2/acet. heat till red at the nut, pull back, if the stud or bolt is also red, do not twist it yet, let it cool, get just the nut hot so as to expand. then just crack it, left right, if it is still tight, add heat again, twist a bit, if still tight add heat again. thus the term HEAT WRENCH! take your time , because if you rush it, you will be spending lots more time drilling or paying the guy with EDM machine ...and thats ugly money.

hobieboy · 10-12-2003, 03:15 PM

Kurt,
I sympathsize...

I was in the same boat a few weeks ago trying to separate the turbo from the header. Torch, dremel, chiesel & cold beer. 3 hours later, the 4 nuts/bolts bulged.

My only optimism is that this will be the last time I have to do that

stainless steel hardware & antiseize hopefully will stop this dead.

Doug Zielke · 10-12-2003, 03:33 PM

Quote:

Originally posted by Kurt V
.... all I have managed to do is cut off the rusted blobs that used to be the nuts on the muffler straps and the catalytic converter. ....

On those expendable fasteners, you can just do what the muffler shop guys do....blow them off with the oxy-ace cutting attachment. My little oxy-ace set has saved me a lot of frustration.
And for the critical exhaust studs, as mentioned by others, use RED heat!!

Rot 911 · 10-12-2003, 03:42 PM

Thanks everyone for the moral support! Tomorrow I am off to the Lowes to get the portable oxy-ace kit and then off to my local gas supplier to get them filled. This won't be my first run in with the dreaded heat exchanger studs and nuts. I had to replace the heat exchangers on my '72. Hopefully no broken studs, but if I break one I'll leave it up to John Walker to get the stud out because I am shipping my heads off to him to rebuild them! Hmmm, maybe that's why he was so quick to jump in on this thread to give me advice!

limble · 05:30 PM

You might also try a crows foot and a flexible extension for the nuts.
Snap-on sells them. Not cheap but nothing on these cars is.
I had to grind two of the hex barrel nuts off. Which brings up a point does our host sell new barrel nuts for the heat exchangers and why can't I use a standard socket head cap screw?

Mike

AFJuvat · 10-12-2003, 07:02 PM

SSI (the same folks that make the heat exchangers) make a good tool for removing the exhaust nuts.

Kurt: Use heat PB blasster, and a little prayer to get the nuts off.

TIP: use anti sieze and copper nuts - they don't gall on the studs like the steel ones do. Replace the "allen nuts" with new ones - Hi temp black paint can help the corrosion issue somewhat if you need to get them off in the future.

Recommend running a die on the studs after you get the nuts off.
Think they are M8 x 1.25

Good luck

AFJuvat