Getting bolts out of exhaust manifolds????

[firstgear]

I working through the various things that need to be done...when the motor was removed and the exhaust was seperated from the exhaust manifold....well....you know.....two of the bolts broke....so I need to replace them...so while I am at it...I thought heck...if two can break now...what about when it goes back together, perhaps others can break....so might as well change them all....

Before I tried anything, I went out and bought some of that PB Blaster (special thanks to Larry/IH2LOSE and everyone else that chimed in on that thread) at local auto store. Sprayed it on exhaust manifolds and let it sit overnight...hit it again and let it sit again....both sides each time...

Tonight I put a pair of vice grips on the exhaust manifold that has that heat riser flapper thingy (those 3 bolts were not broken off and there was some clearance around all the bolts) and with my foot on the manifold grabbed the vice grips and low and behold the screw moved!!! Got it out....and then did the other two the same way....WOW was I amazed......now onto the second manifold.....

It doesn't have any little pockets like the first one did around the studs that would hold the PB and let it work its way in....nor are the threads on the backside as defined on this manifold as the first one.....this manifold also has the two broken off studs. One broke off pretty clean to the manifold, no option there but to drill that one out. Second one has a bit of a stud sticking up of about 1/2" to 3/4", my guess is that one will also be a candidate for drilling. I tried the vice grips on the remaining intact stud....and that sucker did not want to move...no matter what....so I sprayed that one with some more spray and will let it sit over night....but I am not optimistic that one is coming out with vice grips....it seemed to laugh at the vice grips....so....what is my best option???

1 - Try to get it out with vice grips? After more PB....

2 - Cut it off flush with a hacksaw and drill it out?

3 - Try to get it out with vice grips after hitting it with a propane torch?

4 - Other good solutions that have worked for you?


When I get the new bolts, should I run a tap down the holes to make sure the threads are cleaned up? or what else should I do?

Also, thought about sand blasting them while they were out and then putting that gray type of paint on them that cures when the motor is run....or other thoughts?

thanks for taking the time to read this and providing some insight...

Herb

 

[youwish2bme]

Just one thought... Whenever I insert or remove exhaust manifold studs double nut the sucker and then remove vs using visegrips. As for manifold paint you can't beat POR-15's manifold paint. When you do get all of them out yep run a tap thru and when you put the new ones in apply a lot of antiseeze.... Dave.

 

[IH2LOSE]

stud sticking up of about 1/2" to 3/4"

I would prop this manifold up so that the stud is verticle.spray the pb on it and give it a "wrap" with a ball peen hammer to allow the pb to work its way in. Do you have a sears near you. I purchased a set of stud estractors from them that work excellent
http://www.sears.com/sr/javasr/product.do?BV_SessionID=@@@@1481453005.1122026589@@@@&BV_EngineID=ccijaddffddmgfecegecegjdghldghh.0&vertical=TOOL&pid=00946338000

As for the other Stud sears also has these reverse drill bits that worked for me. the drill bit is designed to bite in and spin the stud out and it seems you as your drilling its actually adding heat to the stud until it realises.

Good luck if you have a sand blasted I would clean up whats left of the threads to loosen things up







When I get the new bolts, should I run a tap down the holes to make sure the threads are cleaned up? or what else should I do?


Yes definatly use a tap. I was taught to always run a tap thru what ever your going to assemble,Been doing it forever and would not think of putting something together with out a tap on hand.

Once you start using them consistently youll wonder why you always did not use them,Make life real easey

 

[paul67]

You can try a stud remover on a 1/2" rachet handle. It does not slip like vice grips.

 

[jerrybramlett]

When I've encountered truly frozen studs, the only way I've found to get them out is to use high heat.

If you heat the metal around the stud to cherry red, it will expand the size of the stud hole enough to free the stud. If you heat the stud directly, it will grow in diameter and become even more stuck in the hole while hot. Sometimes I heat the area around the stud and then touch the stud with paraffin wax. The wax will melt and wick down into the frozen threads.

Using a large reverse drill bit is a very good idea for the stud that is broken flush. I would apply high heat and paraffin first though. Then hit it with the drill bit.

Drilling has not worked well for me other then to make a smaller hole for an "Easy-Out". If you try to drill out the entire stud, you run a high risk of getting into the original hole threads. You will not be able to salvage the original threads using a tap. Using an oversize drill for a Heli-Coil doesn't work well either. It's very difficult to perfectly align any new stud hole with the original.

 

[studiog]

MHO: I would agree with the heat around the stud and not so much on the stud itself. This has worked well for me almost every time. Propane may not be enough heat. Try a MAPP gas torch. Put the manifold in a vice if you have one, heat up real good and then use the stud remover preferably, two locked nuts on the stud or the vise grips. Good luck!

 

[firstgear]

thanks to everyone....this weekend I am also building a bench to mount the vise that I bought to....I have a MAPP torch at the other house so I will give it hell this weekend when I go over I will bring that back with me.

not having the bench is a problem....working on the driveway or top of a garbage can just doesn't cut it.....so this weekend the bench gets built....that way I can make it taller than a normal bench and won't have to hunch over when I work on stuff (I am 6'2").

I was pretty proud getting the first three out, but then that wasn't the side that had the problem either.....the other one is where the two bolts broke off and it looks like the studs are fused into the manifold....so this should be a lot of fun getting them out....I will use all the comments above and just plain muscle to get the apart.....thanks for the comments....

 

[JohnZ]

For the ones that are broken off, turn the manifold upside-down and use some modeling clay to build a "dam" around the hole, then fill with PB Blaster or Kroil and let that work for a day or two, then attack with the other methods noted above.

 

[henny496]

stud removal

Hello
The problem with drilling the stud out is that the bolt is a lot harder than the head. The drill can wander into the casting and then you are #$%^%@ ed.
Try heating around the stud, very gently, and then vise grip it. I know of guys who can blow out studs with a torch, but would not reccomend trying it, unless you are very proficient with a torch
Tom

 

[firstgear]

Hello
The problem with drilling the stud out is that the bolt is a lot harder than the head. Tom

oh great....something harder than my head.....

 

[gec]

If you decide to try an easy-out or stud extractor just be very carefull, if you snap it off inside the broken bolt you have a real problem.

 

[henny496]

stud removal

Hello
If you try to drill it out, and after grinding the stud as flush to the head as you can(flat) bolt the exh manifold on. You can then set it up on your dril press table (if it tilts) and use the manifold as a drill guide to kep your drill centered. Start at the hole size of the manifold( approx 13/32) and then after the drill has made a good center mark go down to the largest easy out you can get in.
If you have to you may have to go to 5/16 and retap the 3/8 hole. If so, use a really good or new HSStap and lots of tapping fluid . be careful
take care
Tom

 

[stepinwolf]

My two cent's

I have NEVER, encountered a frozen manifold stud, that could not be removed with high heat. I use an oxy-acetylene torch, and after getting the manifold cherry-red, to almost white, most of the time it will back out with ease. If the stud you are trying to remove has rusted threads protruding from the opposite side, you would be better off by screwing into the manifold , and out the other side rather then trying to back it out.

Most of the time, when bolts are removed from our Corvettes from areas that are not accessible, the rupture of the bolt is caused, not by the bolt being frozen in the threads, but rather the accumulated rust on the exposed threads, that seize up when backing them into a threaded area.

If you encounter resistance once the manifold is red-hot in backing out the bolt, give the bolt ( bolt only ) a shot with a spray bottle filled with some water. This will help in reducing it's hold in the manifold, making it's removal easier.


Be extremely careful if you have to resort to using any type of bolt extractor. If the sh*t hits the fan, and you break one off in the hole, their drilling becomes impossible, and the only way to remove them is to spend two to three hours, in carefully chiseling them out with a hammer and chisel, one small piece at a time. It's the only way I have ever been able to remove them from a hole

I promise you it's not really a fun thing to have to do.

 

[WayneC]

"4 - Other good solutions that have worked for you?"

Jerry & Step have the answer. I simply carted mine down to a muffler shop and they applied high heat and got the frozen studs out easily... they are used to facing this problem every day so they get very proficient at it. Only cost me a few bucks. Of course, now that you've broken studs off flush, you are probably stuck with drilling and tapping them.

 

[MMM]

A word of caution about drilling out broken exhaust manifold studs; a posting for what it's worth.
Was brought a '58 Cad Eldo Barritz, that I had previously worked on, because the owner had the engine compartment detailed and afterwards the car would not run. Seems the person who detailed the engine took it out to do the job. Found the problems and got it going again, but noticed a coolant leak. Traced the leak down to one of the center bolts on the left exhaust manifold. Now on the 49 to 63 OHV Cad V-8 both of the center bolts in the ex. manifold end in a cylinder head bolt hole, they are not dead ended. The cyl. head bolt hole is 2 1/2" deep. To pull the engine, Bubba takes off the exhaust manifolds, but breaks one of the center bolts on the left side. So after getting the engine out, he decides to drill out the broken stud. And he drills, through the broken stud, through the head bolt, and onward through the head casting into the water jacket! One '58 Cad head down the drain! I even found the broken end of the bit still in the head. I checked around to locate a welder who would attempt to repair the original head and as of yet have not found one. Did find a '59 Cad head and after reconditioning, have installed that.
But, in my search for a person to repair the head found out this type of screw up is COMMON! People removing broken studs, and drilling into the water jacket. IF the stud does not end up in a head bolt bore then the common fix is JB Weld and RTV. So mark your bits for depth if you have to drill out a stud. This is the first time I have seen this, but I guess it is not for others!

 

[firstgear]

A word of caution about drilling out broken exhaust manifold studs; a posting for what it's worth.
Was brought a '58 Cad Eldo Barritz, that I had previously worked on, because the owner had the engine compartment detailed and afterwards the car would not run. Seems the person who detailed the engine took it out to do the job. Found the problems and got it going again, but noticed a coolant leak. Traced the leak down to one of the center bolts on the left exhaust manifold. Now on the 49 to 63 OHV Cad V-8 both of the center bolts in the ex. manifold end in a cylinder head bolt hole, they are not dead ended. The cyl. head bolt hole is 2 1/2" deep. To pull the engine, Bubba takes off the exhaust manifolds, but breaks one of the center bolts on the left side. So after getting the engine out, he decides to drill out the broken stud. And he drills, through the broken stud, through the head bolt, and onward through the head casting into the water jacket! One '58 Cad head down the drain! I even found the broken end of the bit still in the head. I checked around to locate a welder who would attempt to repair the original head and as of yet have not found one. Did find a '59 Cad head and after reconditioning, have installed that.
But, in my search for a person to repair the head found out this type of screw up is COMMON! People removing broken studs, and drilling into the water jacket. IF the stud does not end up in a head bolt bore then the common fix is JB Weld and RTV. So mark your bits for depth if you have to drill out a stud. This is the first time I have seen this, but I guess it is not for others!

yikes.....in my case I am just after the bolts in the exhaust manifold itself....but certainly a good word of warning from experience, the best teacher!!!

 

[Z28Canuck]

yikes.....in my case I am just after the bolts in the exhaust manifold itself....but certainly a good word of warning from experience, the best teacher!!!

I have a small collar with a grub screw that came with a drill set I got. It slides over the drill and you tighten the grub screw against the drill flute to set your depth and it just acts as a STOP / depth limiter. Great for this application and for working with wood or steel when you don't want to drill all the way through for whatever the reason. Good luck with the stud piece removal. It is great to get all this advice from guys who unluckily had the experience themselves but want to save you from going through the grief and expense of further problems! What a great group!

 

[TLeBlanc]

Lots of great ideas in this thread...... back when I was doing mechanic work for a living, I sort of became the goto guy for removing broken studs and bolts. My mentor, they guy who taught me a lot about wrenching, showed me a method that I use still to this day. He would apply heat to the stud or bolt only, using an oxy/acetelyne torch, getting it cherry red. Once he accomplished this, he would shut off the torch, let it cool for a short while, then spray a penetrant on it immediately. Now you have to be careful because if the temp is still hot enough the penetrant will ignite. Leave it set until it cools enough to touch without gloves, spraying penetrant occasionally, then put the vice grips on it (if possible and try working it back and forth using just enough force, but not too much as to break it off flush. Keep spraying penetrant as you go.

The theory behind this is that by applying the heat to the stud, it expands forcing the rust outward. Applying the penetrant will then be drawn into the areas opened up by the expansion, and voila !!

Sometimes I would weld a nut onto the stud if there was enough room. This accomplishes the heat phase, and then gives me something to put a wrench on when trying to remove.

I have also used the method of applying heat to the area around the stud/bolt, but the process above has been the most successful for me. I also apply a small amount of a product called "Never-Seize" on re-installation of the new bolt or stud.

 

[Vette66AirCoupe]

I have a small collar with a grub screw that came with a drill set I got. It slides over the drill and you tighten the grub screw against the drill flute to set your depth and it just acts as a STOP / depth limiter. Great for this application and for working with wood or steel when you don't want to drill all the way through for whatever the reason. Good luck with the stud piece removal. It is great to get all this advice from guys who unluckily had the experience themselves but want to save you from going through the grief and expense of further problems! What a great group!

My method doesn't involve a STOP but a warning. I wrap a rubber band around the drill bit as many times as it takes to snug up and then slide it to a position that will indicate when I have reached the drilling depth I need. Great visual guide in that it's 3D!