removing exhaust manifold stud tricks ?

[JeepsAreBuilt]

I got an almost 50 year old exhaust manifold I want to replace the studs in them as its going on my CJ5 motor. Heres what I'm working with:

Any good tricks ? I dont want to drill it out and tap. I thought of welding a nut on the stud and use my impact to back it out. Would heating up the cast iron manifold help any ?

 

[Jeff Ivers]

I would use lots of Kroil and either double nuts or a stud extractor. Unless someone more knowledgeable advises it is ok, I would avoid heating the manifold for fear of warping it.

 

[blacK20]

A stud extractor with a little bit of heat(not red hot) will take them right out. I would not worry too much about warping the manifold. The only area that you really do not want warped are the flanges that mount to the head, and that is far away from where you need to heat.

 

[toolfreak]

I would heat it up and use wax. Try to get it to come out with vice grips. Once it starts to unscrew, you may have to reheat and reapply the wax.

 

[vpd66]

I was taught how to remove exhaust studs many years ago when I went to tech school. Heat the manifold with a torch around the stud (not the stud) until it is red hot. Take a water soaked shop rag and quech it quickly. Then grab it with a visegrips and use a back and forth motion until it is out. I've done many dozens of manifolds through the years and it always works for me.

 

[Red Green]

I was taught how to remove exhaust studs many years ago when I went to tech school. Heat the manifold with a torch around the stud (not the stud) until it is red hot. Take a water soaked shop rag and quech it quickly. Then grab it with a visegrips and use a back and forth motion until it is out. I've done many dozens of manifolds through the years and it always works for me.

I do it the same way without the water rag. If the stud starts to squeak when I am turning it out I stop and heat the manifold more.

 

[omr]

had an old timer show me a little trick that has saved me from having to remove quite a few manifolds..

i heat the manifold carefully with a torch , obviously not to the point the cast iron starts to melt but to the point it is red , then i take a socket full of the same size nuts that would have fit on the stud and push it against the stud with my impact gun on reverse..

not sure of the science behind it but it has worked every time i have tried it , for some reason the cold nuts grab the stud and spin it out every time ..

 

[Agent1320]

If you can't get it out with heat, penetrating oil, wax, etc. Drop it off at a machine shop and tell them you want the studs removed and the threads chased and you want the flanges resurfaced. Won't cost much more than a simple resurface job and you'll have smooth/flat surfaces for a leak-free installation.

 

[NASTYZEN]

The principal about using heat to remove a stud is simple. If you heat metal it will grow. Therefore you heat the flange around the stud till it's straw colored. All the while trying to heat the stud as little as possible. The flange grows more than the stud,in theory..... I like the quench the stud idea,should shrink it as well and make the stud less plastic in consistency.
Anyhow,when I served my time in a muffler shop,when the above method failed we would torch the stud flush with the flange.Yep.
We had a cutting torch that was strait,not L shaped,for this purpose.
Cast iron melts at a higher temp than the steel stud, so we simply took a *************.
Heat the stud till it starts meting and squeeze the trigger and blow the stud out of the hole. The trick is to not stop t'ill it's all gone,or else it's impossible to start again. The open holes are a little trickier to do.
Once cooled ,Tap and your good to go.
We had heavy leather coats ,hats n gloves so as to not stop halfway thru a cut because of skin on fire.......

 

[rsanter]

if you have the time then clean aff as much rust as you can and soak in penetrating oil to start.
then double nut the thing and heat the flange and give it a try.
if that dosent work then get the wax out and do it again

bob

 

[vpd66]

I was taught how to remove exhaust studs many years ago when I went to tech school. Heat the manifold with a torch around the stud (not the stud) until it is red hot. Take a water soaked shop rag and quech it quickly. Then grab it with a visegrips and use a back and forth motion until it is out. I've done many dozens of manifolds through the years and it always works for me.

I also use this method on every brake bleeder screw and have never had it fail. I've done thousands of brake bleeder screws over the years. In fact I did 2 just yesterday.

 

[PCO6]

Like with rusted nuts and bolts, sometimes it's best to "tighten" the bolt (stud) slightly THEN start to loosen it. If you can tighten it 1/10 of turn or even 1/12 or so you can break the rust seal and that will allow penetrating oil to seep in better. I agree with the comments above though - heat up the manifold, and the studs as little as possible, and they should unwind.

 

[diesel research]

you are lucky for multiple reasons.
1. you have exposed threads on both sides
2. the part is removed and easily accessible
3. you aren't on an emergency deadline
4. (and most importantly) you stopped and asked for help BEFORE you broke something.

!

(while the bolt-out extractors won't help one bit, notice the use of heat and aero kroil along with vibration of impact or hammer)

So the common recipe includes heat (and or cold shrinking) various penetrants, and vibration/shock.

Since you have so much available time and space, I would LOVE to see what phosphoric acid or other rust removers do (ospho, jasco, naval jelly, or evaporust) Only a hypothesis, but I suspect it may help penetrants creep deeper.

 

[KCarGuy]

I have had to do this several times.
I put the manifold in a vice, heat the stud with a torch then cool it with some WD-40.
This will shock the rust and pull in some oil.
Then heat the Manifold, while staying away from the stud...More WD-40.
Using a Double Jam Nutted or Vice Grip start working the stud Clockwise-Counter Clockwise until it breaks loose and it may complain the entire time.
It should then, come out.
Good Luck.

 

[zmotorsports]

I have had good luck by spraying with Kroil and letting sit overnight. Then apply heat to the manifold boss and try to keep the direct heat off of the stud. Once heated wrap a wet rag around as much of the stud as possible to both cool the stud and hopefully shrink it somewhat and to make the stud more solid, less plastic, to endure the removal process.

Just before attempting to turn the stud outward smack the side of the manifold near the stud but not directly on the boss as you could deform it. This will sometimes jar the rust/corrosion just enough to break the surface tension and let the stud go.

For stud removal I use actual stud removal sockets that grip the stud on the shank but the double nut process will also work adequately.

Mike.

 

[ptschram]

I have to remove tie rods that are FROZEN into the tie rods, along with exhaust studs.

I set them up so that my salamander is blowing directly on them. Get them close enough that they're too hot to hold, but not so they change color. On the second day, expose them to heat for an hour, pull them away, squirt with Kroil, repeat heat, repeat Kroil, repeat until you're tired of doing it.

After the second or third day, apply a pipe wrench to the stud, gently try to tighten it, Kroil, loosen with pipe wrench, The vast majority spin right out.

 

[tatra]

i have had good lock welding the next size up nut on broken studs, letting it cool and then turning it out...........the heat from the weld seems to break the rust ...........used this numerous times on brken bolts and studs where the t stat housing fastens to the block..............all of the above do infer one common item, patience...........

 

[jayoldschool]

Heat and wax. Good video on youtube...

 

[Test Tech]

I have had to do this several times.
I put the manifold in a vice, heat the stud with a torch then cool it with some WD-40.
This will shock the rust and pull in some oil.
Then heat the Manifold, while staying away from the stud...More WD-40.
Using a Double Jam Nutted or Vice Grip start working the stud Clockwise-Counter Clockwise until it breaks loose and it may complain the entire time.
It should then, come out.
Good Luck.

I agree with this with two exceptions:
1: Use a better oil than WD, use either kroil or blaster.
2: You may need to perform several cycles of heat/oil spray in order to succeed. If you do this once and it doesn't work, repeat until it does.

 

[srmofo]

I always apply heat before attempting to break anything like that manifold stud loose. Usually heat red and quench once, then reheat till its hot, but not glowing. Apply wax and break it loose, work it back and forth while applying more wax until its turning easily. if it starts squeaking apply more wax.

most importantly, dont force it

 

[VWandDodge]

I always apply heat before attempting to break anything like that manifold stud loose. Usually heat red and quench once, then reheat till its hot, but not glowing. Apply wax and break it loose, work it back and forth while applying more wax until its turning easily. if it starts squeaking apply more wax.

most importantly, dont force it

That's what she said!

 

[Davi]

if your really worried about using heat on it instead of welding a nut on put two on together, they'll lock against each other. Not commenting on a way to remove it, just an alternative to welding a nut to it if thats what you decide to do

 

[NASTYZEN]

Well I'LL be darned! Ran across the exact problem today.
I have a huge cast table that I have to level off.It has 1 inch set screws on the perimeter and of course one is just stuck to hell. Messed with it and finally broke the hex and finished it of with vise grips........


/"%$?&*&%5

I have big extractors,so I decide to drill it out. Ha! It's insanely hard and kills my cobalt drill bit........Hmmmm...I remembered this thread and got to thinking....
It would be nearly impossible to torch thru 3'' of bolt...but I happened to have a couple of carbide drill bits.
I was able to drill a 1/4'' hole thru. yes!

Out came the torches and gloves and bingo! I blew that sucker out!

A little tapping.

 

[lilredex]

Once you do get it out, I'd drill out those threads and drop a bolt in from above. Looks to be enough room, and the problem goes away for next time.

I like turning the stud in first and welding on a nut, as was suggested above.

Threads in manifolds are dumb if it can be avoided.

 

[littletoes]

The principal about using heat to remove a stud is simple. If you heat metal it will grow. Therefore you heat the flange around the stud till it's straw colored. All the while trying to heat the stud as little as possible. The flange grows more than the stud,in theory..... I like the quench the stud idea,should shrink it as well and make the stud less plastic in consistency.
Anyhow,when I served my time in a muffler shop,when the above method failed we would torch the stud flush with the flange.Yep.
We had a cutting torch that was strait,not L shaped,for this purpose.
Cast iron melts at a higher temp than the steel stud, so we simply took a *************.
Heat the stud till it starts meting and squeeze the trigger and blow the stud out of the hole. The trick is to not stop t'ill it's all gone,or else it's impossible to start again. The open holes are a little trickier to do.
Once cooled ,Tap and your good to go.
We had heavy leather coats ,hats n gloves so as to not stop halfway thru a cut because of skin on fire.......

Was wondering if anyone else was going to post this....YES! You CAN torch out steel in cast iron.

 

[JeepsAreBuilt]

Thanks for all the excellent tips ! Now to just decide what to do..

I think I may media blast it and clean it up first, then spray some blaster on it and then try heat and stuff.

 

[RBailey]

I like the chuck type stud grabber / extractor in the youtube links.

Anybody got any comments on them ?

I have a cam type but the chuck type on an impact (they are rated for impact) sounds very good !

 

[isaac338]

Thanks for all the excellent tips ! Now to just decide what to do..

I think I may media blast it and clean it up first, then spray some blaster on it and then try heat and stuff.

Just heat the manifold and turn the stud out with a vise grip. Easy peasy.

 

[Griff93]

I have had to do this several times.
I put the manifold in a vice, heat the stud with a torch then cool it with some WD-40.
This will shock the rust and pull in some oil.
Then heat the Manifold, while staying away from the stud...More WD-40.
Using a Double Jam Nutted or Vice Grip start working the stud Clockwise-Counter Clockwise until it breaks loose and it may complain the entire time.
It should then, come out.
Good Luck.

This is how I do them as well except I use penetrating oil. I've done this successfully on CJ5 manifolds as well.

 

[Duck]

Do yourself a favor, after you've removed the studs. Replace them with brass studs, instead of steel.
You won't have this problem again..
Duck

 

[littletoes]

Don't think brass can take the torque.

 

[toolman1967]

Good advise here, Heat til red and quench with lots of cold water. Then remove as quickly as you can. The different expansion of the two metals (Cast and Steel) will be different for each and this helps to separate the two parts.

 

[Drew_flux]

plenty of good tricks here. some times i will heat then use caned air upside down to shrink the stud a little.

 

[papabil]

just heat the manifold around the stud (red) then remove. with vicegrips or whatever

 

[jhelrey]

I'll tell you how real mechanics do it... when you have to cheat that is.

Try to remove the studs. If stuck, cut them off flush, drill new holes, and use bolts. Make sure the bolt is a little smaller than the hole like 1/16. You'll never ever have that problem again.

 

[littletoes]

Real mechanics???

Well, I'm real enough....and I work on so many "old" things, I'm ALWAYS removing broken, rusted studs, just usually a bit larger than what you find in a car. What "I" find, the teeny tiny stuff can be harder than the BIG stuff.

I've drilled 'em out, then peeled out what I can with a diamond point chisel, and if it won't go, I'll run a tap in there. I've heated the object that the stud is in till red, and hit it with Kroil or Rust Buster, and spun it out, I've even had luck with Kroil or Rust buster by itself.

The ultimate is a cutting torch set up as a non-oxidizing flame, and blow that bad boy out, even with hardened bolts, and it doesn't hurt the cast. Be careful though, an oxidizing flame will cut cast.

If its a really big bolt, I've had more luck using a pipe wrench to turn it than just about anything else. I've even had some luck with hardened bolts, and a pipe wrench. Leverage is a key.

Your "stuck" bolts are actually "whimpy" in comparison to quite a few of the bolts I've had to get out....too easy to even worry about actually.

Just be sure to anti-seize the new bolts when you put than in there, and you'll never have another problem.

Funny thing, I've had more luck with the copper based stuff than I have with nickel based stuff.

The Moly based stuff is the best, but boy is IT expensive, and there are some factors that may cause concern when moisture may be present.

I've a quart can of 3M moly anti-seize that is PHENOMENAL, but I usually use the copper stuff, even over the higher rated nickel stuff.

There's more, I just can't think of it right now....guess its late???

 

[littletoes]

And guess what? I haven't even got into "easy-outs"....the old-timer spiral types ****!

I've had great luck with the square cut PROTO versions...takes quite a bit to break one of those...but if you do, boy are you in TROUBLE! hehehe Time for the die grinder or torch.

 

[Jzytaruk]

The frozen bolts i deal with are usually on the under carriage of Dozers and Excavators.. If I cant heat the metal around the bolt, Il heat the bolt itself until its red hot then wait a few minutes for it to cool down and smash it with the impact gun. If I turn the head off, its a simple welding job to fix. More often then not the bolt turns right out tho.. No lube either, operators and bosses dont like it when plooms of smoke come from under a piece of equipment

 

[mrobins297aaa]

whats the wax do? I've never heard of that before

 

[csargents1546]

Kroil, heat and working it back and forth, worked for me everytime so far.