Exhaust Nut Removal

[AdamKaz]

So there are lots and lots of posts around here about soaking your exhaust studs in kroil et al, or heating them up with a torch, or both, or using an impact hammer. or yada yada yada to prevent the fragile studs from breaking.

Sooooooooo, stupid question:

Why do I not just cut the nuts off with a Dremel and leave the stud alone? Give it a good wire brushing to clean it up and install new nuts?

Seems like contorting a dremel or drill or cutting tool around would be easier than breaking a stud and having to drill it out.

What am I missing?

[gazzerr]

I don't know if you can reach all the nuts to cut or split them off. A bunch of them are reached through a hole in in the bottom of the heat exchanger.

[faverymi]

Doing it like this takes 10 minutes.

I drill all day it would probably take me 2 weeks to cut 12 rusty nuts and I probably will damage a stud.

Penetrating oils don't even tickle exhaust hardware.

[john walker's workshop]

Just don't hit the oxygen!

[Superman]

Originally Posted by john walker's workshop

Just don't hit the oxygen!

John makes them jump off the studs in fright.

All comedy aside, favarymi is right. Exhaust studs laugh at penetrating oil and Dremels. You need a blue flame, if you want to ensure the studs stay in place and are not damaged.

[gazzerr]

Is MAAP (MAP?) gas hot enough?

[theiceman]

I used a kit from lowes that was MAPP and oxygen with a pencil tip handle. it worked absolutely amazing.

I had the assembly on the bench with the exchangers still on. I used a 13 mm wrench and a I think maybe 5? mm allen key which stopped me from over torqueing , ot them cherry cherry red and as soon as it went off cherry turned them out , worked amazingly well, don't worry if the stud comes out instead that is even better. of course wear heavy welding gloves.

[JacobS911]

I just did this on my 930. No heat. Just soaked them really well with PB Blaster over night. Used a wrench rather than a socket to break them loose to make sure I wasn't turning the stud. Not sure what I would have done if they had started to turn.. guess I would have gone the heat route. Luckily no broken studs! Good luck!

[morrisjm1]

I didn't use the cutting torch, I just used a "0" or maybe "1" welding torch. You can get right up in there and get the nut red hot without heating other stuff up too much. Get a socket on it immediately and they spin right off. It's handy if you have someone to hand the torch to, otherwise you need you shut it off and have a place to put it.

[gazzerr]

Awesome thanks Guys.

[mikedsilva]

would love to see a video of someone doing this... I'm due to do this in a couple of weeks.. very nervous here!

[universeman]

Mine came off pretty easy with CRC Freeze-Off liberally applied, after 2-3 weeks of hitting them with Kroil and Gibb's every few days. YMMV.


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[AdamKaz]

FYI -

Tried the traditional soak for 3 days with penetrating oil and then MAP flame for 7-10 minutes. Immediately broke the first stud

Tried cutting them off with my dremel. Easiest thing in the world. Cut all the nuts, then cold chiseled them to rotate or break apart. Got all the HEX bolts but 1 just find with a hex wrench. The last one was stripped so I cut that one off as well.

I HIGHLY recommend just cutting the nuts to anyone.

[sugarwood]

Originally Posted by AdamKaz

Got all the HEX bolts but 1 just find with a hex wrench.

Can you clarify what you're trying to say?

[sugarwood]

Can you explain how you cut the nuts with a Dremel?
Is the cutting wheel parallel to the nut? Or perpendicular?

If the latter, I don't understand how the wheel can cut through the nut.
Unless you have a microscopic cutting wheel, it will hit into the header flange and the stud itself.

[sugarwood]

Wait, I bet you didn't use a cutting wheel at all.
Did you use a cutting burr like this?
Once you grind away a chunk, you just rotated it with chisel, and made another cut?
Once it was in 3 parts, it just fell away?
How did you make sure not to grind the newly exposed threads underneath?

[911pcars]

Originally Posted by sugarwood

Can you explain how you cut the nuts with a Dremel?
Is the cutting wheel parallel to the nut? Or perpendicular?

If the latter, I don't understand how the wheel can cut through the nut.
Unless you have a microscopic cutting wheel, it will hit into the header flange and the stud itself.

I had to use all three on some exhaust fasteners (heat, wrench, Kroil and Dremel). Okay, that's four.

Apply penetrating oil (PO) first, then allow to soak. Alternate heating and cooling cycles with PO. If that doesn't budge (don't neanderthal it), proceed.

Slice a long diagonal kerf into the nut with a small dia. Dremel cutoff wheel - avoid slicing the stud. Add multiple slices if needed. Widen the kerf it possible, then insert a chisel or equiv. into the slot and twist to widen the gap to reduce it's grip on the stud (extensions and leverage helps). Some heat will help soften the nut. Repeat hot/cool cycles with PO into the kerf so it flows into places where the sun heretofore don't shine.

A barrel nut on a 911 may take this form after petrification is defeated:


Be patient. Do not break the stud(s).
Sherwood

[fred cook]

The heat exchangers on my SC were in really rotten condition so I used a sawzall to cut the down pipes. That got enough "stuff" out of the way to allow access to the (very) rusted flange nuts with a torch and assorted sockets, etc. After rebuilding the engine, I reinstalled the SSI exhausts with the engine upside down on a stand. Much easier that way!

[stormin48061]

i drove my car down to the local exhaust shop where i take all my exhaust work, so they know who i am and a loyal customer. they guy in there does older muscle car stuff and a great guy. they heated up the nuts as shown and cracked the nuts. They backed them down the stud so i could just take them off when i go home.... dropped 20 bucks in the coffee jar and all was good.... best 20 bucks i've spent on the car.

[Elombard]

^ thats great i will try that next time. Have to look for the Mapp Oxy kit at lowes. I think I have seen them - Are they like a $100?