How to minimize rusty exaust manifold bolt/stud breakage?

[TireTracks]

I'm going to be putting a set of headers on my dodge in a few weeks/months. and i need to removed the stock manifolds.

I want to keep the 4 studs in the block to reuse, and take the 4 bolts out, the studs need to stay as they go though coolant passages and i dont want to have to deal with that mess.

how should i go about removeing the nuts/bolts with minmal risk of breaking them? i have a small propain torch, an impact wrench, and i can soak it in oil if i have too.

How would you do it?

 

[BackTracker]

Prayer, lots of it.

 

[Skin]

dont use an impact wrench if you can avoid it. If you can get the leverage a breaker bar would be better so you can gauge how much force you're using. If its rusted on good the impact wrench is a sure fire way to snap the stud.

Penetrating oil for awhile, heat, then take a crack at it.

 

[BackTracker]

I usually use the impact gun, if I use a breaker bar...Snap!

 

[sdowney717]

heat the stud ends and nut with the torch.
brush them off a little
spray it with pblaster
run some nuts onto the studs.
It would be nice to use castellated nuts. Run them on backwards so they can help clear the rust.
You could cut slots in the nuts yourself. this works similar to a die and aids in clearing the rust.
Use a hard grade 8 nut for this.

 

[y20dth]

If you -between now and the day you remove the bolts- spray them daily with any creeping oil (both cold and hot), you will be amazed at how easy they wil come off.

 

[TuffXR]

Anti-sezie is your friend.

 

[joenero]

Agree with the PB blaster comment. I did headers not to long ago on a car with rust and I did get the chance to spray it a couple of times before hand. I was quite happy with how easily everything came apart.

 

[daveblank]

I want to keep the 4 studs in the block to reuse, and take the 4 bolts out, the studs need to stay as they go though coolant passages and i dont want to have to deal with that mess.

Manifolds are usually thicker. Therefore the studs will be longer. If they are too long, they will not work & will need to be changed anyway.

 

[Kevin54]

Don't horse them out right from the get go. Try to tighten them a hair the loosen them a hair. Keep doing this back and forth to keep the rust worked loose until you finally get them out. Clean out the threads with a tap, clean off the threads on the studs with a chaser, and use Anti-Seize on the new threads.
BTW...I'm not familiar with Dodge products, but are you positive that the studs go into the water jacket? I guess I've always messed with Chevy's and never heard of that. I can see your concern though if they do.

 

[RattytatTom]

I've done this recently on an old F250.
sdowney717 is right. Heat 'um with a small torch, or by running the engine. Spray with KROIL (the best struff out there). Let it soak every day. Then slowly try to break them loose. If they dont want to budge, stop and repeat the process.
Every one of mine broke loose using this method.

 

[plinker]

I removed the manifolds on a ford 2.9L by soaking them with kroil at least twice a day for 3-4 days(pentro 90 for the previous week).
Then I "rocked" the bolts back and forth with a ratchet.

I managed to break only one (The ratchet didnt "catch" on the pawl and didnt change derction) and that was simple enough to drill out with an air angle drill and stubby drill bits (1/8 to 3/16 to 1/4).

The reason mine got taken off I needed the Y-pipe off and wound up removing the manifolds. Y-pipe was in the way of removing the transmisson.

All bolts are getting replaced too.

 

[joeswamp]

I've done this before, using the aforementioned technique of soaking in Kroil multiple times per day for several days, then broke them loose with a breaker bar. This is one of those jobs where a 1/4" impact might be helpful -- not to do the actual unscrewing, but just to introduce some vibrations into the rusted assembly while soaking.

I'm not sure how I'd do it if I were a professional mechanic and had to do it in 15 minutes, I guess the torch would be the only way.

 

[BlindViper]

I dont even bother soaking them with oil. I just get out the torch. I removed a manifold on a 96 civic with 290k on it took about 20min? I welded the crack up and reinstalled it.

 

[sdowney717]

using an oxy-acetylene torch obliterates the rust. Just be careful not to set the engine on fire, destroy something, etc...
I have used my torch to loosen the hub nuts, and tie rod adjustment sleeves and lock nuts. On a Contour, I could nut get those nuts to loosen until I heated then cherry red.

I recently aligned my buick roadmaster wagon and the upper control arm nuts that hold the spacers were locked in good with rust.
The bolts where they pass thru the upper arm were locked up with rust. It took some work and there was no way a torch would have been safe in there. Simply a lot of PB Blaster and pry bars and hitting on them managed to get it loose. I even used the cars weight as leverage to help loosen the bolts. As in dropping the jack down which forced the tire up and loaded the bolts. It was tighten the nuts down, loosen them up, drop car type of idea. Afterward I greased it well. I suppose I could have used antiseize instead of grease.

They were so badly joined together with rust, I wondered how a professional alignment mechanic would have coped with that. Perhaps it would have been, drive car into bay, hour later mechanic claims, he could not align car, and charged me anyway for the time.

 

[sberry]

I couldnt work on a car without a real torch.

 

[rsanter]

spray them with PB blaster every day several times a day from now till you are going to pull them off

bob

 

[ZRX61]

I used kroil when I changed the exhaust gaskets in my old '64 Galaxie. I removed everyone of them without any breakage. It was only after the event that someone told me it was "impossible to remove the exhaust bolts from an FE engine without breaking them"

As I didn't know that at the time I just went ahead & removed them without breaking any...

 

[ozzy214]

I just did a dodge v-6 job in a dakota. Studs were all rotted, no head left to grab. So I cut what was left of the head off and slid the manifold up and over the broken bolts. I then took some turbo sockets and grabbed the broken bolts. Used a quarter drive rachet and just kept tapping it till the broke.

It seems that the rust in the manifold seizes the bolt more than the head. I would just cut the heads of the bolts off. Slide the manifold off and then use some turbo sockets,much easier.

 

[Gareth68]

I don't know how much access you have to them. Aircooled VW's like to break head studs after years of rusting in peace. I use the PB and heat and get most of them. When I get one that simply does not want to budge, I cut the nut with a sharp chisel. I haven't broken a stud in many years.

 

[caper]

Heat the nuts,not the studs,with your torch and use a 3/8dr breaker bar to work the nuts back and forth a little at a time.I'm talking just put the bar on the nut and go back and forth between loosening and tightening without really reefing on them.The back and forth motion and the heat will get the nuts to start moving a little at a time and prevent the stud from twisting off.Don't try to take the nut off in one shot.Stop every 1/4-1/2 turn if it's tight and go the opposite way so the threads will clean out and the stud isn't twisting.I've literally removed thousands of manifold studs,worked in a muffler shop for years.It's not that hard as long as you take your time.Rushing will just cause you to break them and end up taking longer.We used to take out Chevy studs that were rusted down from 3/8 to the size of a pencil lead.Just takes heat and patience.

 

[Art From De Leon]

Since studs have a habit of corroding themselves to the the piece they pass thru, you might wind up having to replace them anyways.

 

[speed bump]

I used kroil when I changed the exhaust gaskets in my old '64 Galaxie. I removed everyone of them without any breakage. It was only after the event that someone told me it was "impossible to remove the exhaust bolts from an FE engine without breaking them"

As I didn't know that at the time I just went ahead & removed them without breaking any...

I have to admit that is pretty impressive.

 

[rockchucker]

Aero-Kroil. Ever since I have found it I have not used PB-Blaster,WD-40 or any other Penetrating Oil again.


http://www.gamaliel.com/cart/product.php?productid=23


Spray it on right after you get done with a long drive and repeat the process a few times before you start your project. Parafin Wax works if you get on the Bolt/Nut with a Torch then apply the Wax.

 

[rsanter]

when I put engines together I always use stainless bolts on the exhaust.
wont have that problem again

bob

 

[Packard V8]

Surprised no one has mentioned using a nut cracker.

I've seen nuts so rounded nothing I had would grab them. For those nuts which can be reached and cracked, it is one more tool in the battle against rusted nuts. Sometimes you need them all.

thnx, jack vines

 

[Art From De Leon]

This is where a 6" RIGID pipe wrench works well.

Avoid using Vise-Grips at all costs, they will do nothing but chew up the stud or nut, and slip.

 

[TireTracks]

Don't horse them out right from the get go. Try to tighten them a hair the loosen them a hair. Keep doing this back and forth to keep the rust worked loose until you finally get them out. Clean out the threads with a tap, clean off the threads on the studs with a chaser, and use Anti-Seize on the new threads.
BTW...I'm not familiar with Dodge products, but are you positive that the studs go into the water jacket? I guess I've always messed with Chevy's and never heard of that. I can see your concern though if they do.

Yep, everyone i talked too that has run headers says that all 4 on both sides run though water jackets, and they make a huge mess if you pull them out.

the flanges on the hedders i'm going to get are about the same thickness as the flanges on the manifolds, and i've been told that they work just fine for hedders.

Thanks for all the advice. I;ll have to pickup some kroil/pbblaster( just saw it for the first time at the store).

 

[Sloper0204]

Here's a thread detailing a nifty tool for heating the bolts/nuts:

http://www.garagejournal.com/forum/showthread.php?t=47670&highlight=induction+heat*

 

[ZRX61]

Don't forget the 50/50 acetone/ATF method.. slightly better than Kroil.... remember to shake it as it seperates in the bottle.

 

[TireTracks]

Here's a thread detailing a nifty tool for heating the bolts/nuts:

http://www.garagejournal.com/forum/showthread.php?t=47670&highlight=induction+heat*

If only i was made of money.


Will the PB/Kroil/AcitoneATF mix get to the threads on the bolts? i wish they had just used 8 studs intead of 4 studs and 4 bolts on each.

 

[ourkid2000]

Some great info here.........learned a lot

 

[Shadowdog500]

Kroil is the best stiff I ever used. I get it by the gallon. I don't know if you could get a nut splitter or that electric nut heater on a manifold bolt. I really like that electric heater though.

Chris

 

[TireTracks]

I'll try mixing up some ATF and acetone, never seen kroil and i think i have some atf and acetone.

How do you do it?just put a cup of acetone and a cup of ATF in a spray bottle?

heres the best picture i have, i cleaned up most of the grease and oil that it was covered in, plently of room.

This is going to look so much cleaner with most of that **** gone, 80% of the vacume tubes and things bolted to the engine are related to egr and the smog pump.

 

[Skin]

never seen kroil

its incredibly expensive and as a result very overrated.

Gunk Liquid Wrench works just about as well and costs a hell of a lot less.



Yes half and half the ATF/Acetone. Just keep in mind Acetone is extremely flammable.