Ford Lehman 120 Broken Exhaust Elbow Stud

[Ttsaang]

I'm replacing my exhaust elbow and while removing it I broke one of the studs/bolts. Any advise on removing and replacing the stud? Thanks

 

[SoWhat]

Soak stud with PB Blaster. Apply heat to manifold. Rinse and repeat.
It looks as though you can get 2 nuts over what's left so be patient. Too much torque will break it off flush. Then you will have to drill it out and install helicoil.

I would probably put a nut on top to protect the threads, heat up manifold so it's a little too hot to touch, then spray PB Blaster, then tap nut with hammer. Keep repeating.

If you have a wire fed welder just weld a nut on top and heat should break it free.

 

[Portage_Bay]

I've had better results with Kriol https://www.kroil.com/ I prefer the version with silicone. Used to be called silikroil.

I once watched an older, very experienced, mechanic use heat then cold. It worked. He said it broke the rust loose.

Patience is important, don't get in a hurry and force it. Sometimes trying first to tighten it a tiny bit will break the rust bond. As soon as it twitches stop.

Once you get it moving a bit you may have to repeatedly tighten and loosen. Add more penetrant. Each iteration will move it a bit further until it comes out. Patience.

 

[av8r]

Some of us might be nervous about using a welder in the engine room, but you could unbolt the manifold and take it to a machine shop for removal and installation of a helicoil if necessary. Be very patient, I believe the manifolds are very difficult to find.

 

[RT Firefly]

Greetings,

 

[Cigatoo]

Greetings,

If we could only learn such things at a young age

 

[jleonard]

I had the same problem. Nothing I did would allow me to remove the stud.
I removed the manifold, brought it my son's auto repair shop and he had it out in less than a minute.
Heated it cherry red, stuck a crayon on it to let the wax suck in between the stud and the manifold and put a vise grip on it and it easily spun out.
I tried heating it on the engine but the mass was too much for me to get it hot using what I had which was a map gas torch.
While it was out I had that end surface machined clean to get rid of the corrosion that was there in one location.

 

[Ttsaang]

Soak stud with PB Blaster. Apply heat to manifold. Rinse and repeat.
It looks as though you can get 2 nuts over what's left so be patient. Too much torque will break it off flush. Then you will have to drill it out and install helicoil.

I would probably put a nut on top to protect the threads, heat up manifold so it's a little too hot to touch, then spray PB Blaster, then tap nut with hammer. Keep repeating.

If you have a wire fed welder just weld a nut on top and heat should break it free.

There’s no threads left so I can’t get any nuts on. Those are marks from the vice grips. I’ve been using some heat and Liquid Wrench. I’m going to get a better pair of vice grips today and keep working at it. Thanks

 

[Ttsaang]

Soak stud with PB Blaster. Apply heat to manifold. Rinse and repeat.
It looks as though you can get 2 nuts over what's left so be patient. Too much torque will break it off flush. Then you will have to drill it out and install helicoil.

I would probably put a nut on top to protect the threads, heat up manifold so it's a little too hot to touch, then spray PB Blaster, then tap nut with hammer. Keep repeating.

If you have a wire fed welder just weld a nut on top and heat should break it free.

I don’t have a wire welder but I will get some PB blaster today and keep patiently working at it.

 

[Ttsaang]

Greetings,

? thanks

 

[Ttsaang]

I had the same problem. Nothing I did would allow me to remove the stud.
I removed the manifold, brought it my son's auto repair shop and he had it out in less than a minute.
Heated it cherry red, stuck a crayon on it to let the wax suck in between the stud and the manifold and put a vise grip on it and it easily spun out.
I tried heating it on the engine but the mass was too much for me to get it hot using what I had which was a map gas torch.
While it was out I had that end surface machined clean to get rid of the corrosion that was there in one location.

I’ll keep working at it but I might end up having to do the same. It’s in an awkward place and hard to get concentrated heat on it. Was it hard to get the entire manifold off?

 

[Ttsaang]

Some of us might be nervous about using a welder in the engine room, but you could unbolt the manifold and take it to a machine shop for removal and installation of a helicoil if necessary. Be very patient, I believe the manifolds are very difficult to find.

Thanks, I might have to do that.

 

[SoWhat]

PB Blaster (or Kroil) and heat. Use a mapp gas torch. Once you get manifold hot, spray stud then tap it with hammer. It might take an hour or two. Acetylene torch would make quick work of it but guessing most of us don't have a portable setup.

Start soaking manifold to head studs in case you have to remove manifold.

 

[jleonard]

I’ll keep working at it but I might end up having to do the same. It’s in an awkward place and hard to get concentrated heat on it. Was it hard to get the entire manifold off?

No not hard didn’t take long but it’s heavy.

 

[RT Firefly]

Greetings,
You have to be VERY careful heating cast iron with acetylene. MAPP will work eventually IMO. As mentioned, patience. Might even take days!

 

[jleonard]

PB Blaster (or Kroil) and heat. Use a mapp gas torch. Once you get manifold hot, spray stud then tap it with hammer. It might take an hour or two. Acetylene torch would make quick work of it but guessing most of us don't have a portable setup.

Start soaking manifold to head studs in case you have to remove manifold.

No way mine was getting hot enough with just a map gas torch but it was in the winter in Ct and everything was ice cold.
Once I made the decision to remove the manifold I didn’t have more than 1 1/2 hours of labor into it for the complete Rand R

 

[Ttsaang]

Success

I was able to remove the stud today. It was a combination of PB Blaster, propane torch, wax and a stud extractor that I picked up from the parts store. I hit it with the PB, heated it for a long time and then touched the wax to the stud which sucked into the threads and slowly was able to move the stud back and forth with the extractor. Kept repeating this process with more movement each time and it eventually wound out.

 

[Frosty]

Sweet!

I'd never heard the wax tip. Read about it and now see how it worked all in the space of a few posts

 

[Comodave]

Good work, I also like PB Blaster.

 

[RT Firefly]

Greetings,
EXCELLENT!!!!!!!

 

[catalinajack]

I have never seen a stud extractor like that. Who makes it? Looks like a handy tool to have in the toolbox.

 

[jleonard]

Sweet!

I'd never heard the wax tip. Read about it and now see how it worked all in the space of a few posts

I never heard of it until my son showed me when he worked on the manifold.
He sees a lot more problems like that than I ever would

 

[TWedd]

Im late to the thread, but they have a induction heater for bolts that is on my short list. it would make short work of this.

 

[Ttsaang]

Stud Extractor

I Picked up this Extractor at the local parts store. It worked quite well. It bites down on the stud as you use a ratchet or wrench on it.

 

[Ttsaang]

Sweet!

I'd never heard the wax tip. Read about it and now see how it worked all in the space of a few posts

Another tip I had was to use a propane torch to heat the manifold so the metal expands and once it's good and hot turn the propane torch off and on again so it's only the cold propane gas coming out and direct it at only the broken stud for a few seconds to shrink the stud metal and then give it a go with vice grips or an extractor.

 

[Ttsaang]

Exhaust Elbow gasket silicone

One more question...
My new exhaust elbow and gasket should arrive from American Diesel next week. I'm pretty happy with the mating surface of the manifold that the gasket and elbow will attach to. Should I use some temperature / water resistant RTV sealant on both sides of the gasket as well?

 

[SoWhat]

One more question...
My new exhaust elbow and gasket should arrive from American Diesel next week. I'm pretty happy with the mating surface of the manifold that the gasket and elbow will attach to. Should I use some temperature / water resistant RTV sealant on both sides of the gasket as well?

Yes, but you should use HIGH-TEMP sealant.
Also coat all threads with anti-seize compound.

 

[catalinajack]

American Diesel recommends Permatex #2 on the manifold side only. I replaced mine last year having driven to AD in Kilmarnock, VA and consulting with Brian when picking up the elbows.

 

[SoWhat]

If I had an open tube of #2 I would use it. If I had to buy a tube I would buy high-temp. #2 is good for 400F, high-temp to 650F. The exhaust elbow requires a gasket so any type of sealant/gasket material is probably OCD.

 

[gonesailing13]

Just curious , why were you replacing the elbow ?