I'm trying to get exhaust manifold bolts out, I've sprayed them with pb blaster for 2 weeks and welded a nut on the bolts but they keep breaking off, any ideas other than drilling them out?
Thanks
Thanks
remove exhaust manifold bolts
- Thread starter dart67
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74dusterDE
Member
Go and get yourself some kroil and soak the crap out of them overnight. Heat em in the morning and they should break loose. For some reason kroil breaks down rust and corrosion like crazy.
74dusterDE
Member
Oh yeah also get yourself an extractor set will save you a ton of headaches and they are pretty cheap
Done Swimmin
Well-Known Member
Buy some plain putty at the hardware store and build a small "well" around each stud. Fill the "well" with what ever solvent you prefer (PB, WD40, etc..) and let it soak for a few more hours (24?).
Peel of the putty and heat the area with a propane torch to warm it up to near operating temp and spray the "stud only" with butane lighter fuel.
This will cause a significant temp difference between the head and the stud breaking most any hold. When it cools soak it again with your solvent and try to move the stud. If it breaks your drillin'
Peel of the putty and heat the area with a propane torch to warm it up to near operating temp and spray the "stud only" with butane lighter fuel.
This will cause a significant temp difference between the head and the stud breaking most any hold. When it cools soak it again with your solvent and try to move the stud. If it breaks your drillin'
heat them red hot with a real torch spray cold water on until cool then weld a nut on and turn it out with your fingers .
swifty
Well-Known Member
"Peel of the putty and heat the area with a propane torch to warm it up to near operating temp and spray the "stud only" with butane lighter fuel."
Sounds like a good method. What is the advantage to butane over kroil or water?
Sounds like a good method. What is the advantage to butane over kroil or water?
65-440
Well-Known Member
MAP gas torch, extractor set, and some patience ! good luck ...
You have to be referring to the studs at each end of the LA head. end in water jackets. They always break.
Here's what you do... Bolt the exhaust manifold back on the head. Now you have a 3/8 diameter pilot hole for centering your 3/8 drill bit or better yet the center drill with 3/8 shank ( I forget the number on that ).. Drill the casting and broken stud about 1/8 inch deep. Now you have a good center to guide 1/4 inch drill bit. drill through. 5/16 tap to clean up remnants in the threads and you're done. Don't forget the RTV on the new studs.
Here's what you do... Bolt the exhaust manifold back on the head. Now you have a 3/8 diameter pilot hole for centering your 3/8 drill bit or better yet the center drill with 3/8 shank ( I forget the number on that ).. Drill the casting and broken stud about 1/8 inch deep. Now you have a good center to guide 1/4 inch drill bit. drill through. 5/16 tap to clean up remnants in the threads and you're done. Don't forget the RTV on the new studs.
Cut off the stud even with the head. Put a bubble of weld back on the stud with a tig welder not a mig. this will heat the stud/bolt threads. Now tig weld a nut to the bubble you put on. cool it quickly with air and they will spin right out.
You must cut them flush when you do the weld trick. and you must use a tig welder. a mig weld is brittle and will break. Also the tig will put more heat in the bolt/stud. We do this all the time on motors in the vehicle or with the head off. This method will not work if there was a he-la coil installed in aluminum.
You must cut them flush when you do the weld trick. and you must use a tig welder. a mig weld is brittle and will break. Also the tig will put more heat in the bolt/stud. We do this all the time on motors in the vehicle or with the head off. This method will not work if there was a he-la coil installed in aluminum.
I wish you were here so I could help ya,take your time and do whats been said youll be allrite.......good luck Artie
trapster
Well-Known Member
Do not I repeat do not try to use a bolt extractor.
Everytime I have tried to use one of those they beak off in the head. Once this has happened good luck trying to drill it out. The extractors are much harder than the original bolt and head and harder than most drill bits.
you are better off just drilling it out and retapping it.
Everytime I have tried to use one of those they beak off in the head. Once this has happened good luck trying to drill it out. The extractors are much harder than the original bolt and head and harder than most drill bits.
you are better off just drilling it out and retapping it.
65-440
Well-Known Member
have to take your time, and use heat ! And don't buy cheap extractors, find a snap-on truck and get a set. I have not broke one yet, patience is a must !
trapster
Well-Known Member
yea I pretty much destroyed the craftsman set.
trapster
Well-Known Member
remember to use hardened bolts and anti seize grease when reinstalling them
Tinbasher
Well-Known Member
Go with Redfishes method. It will work! Trick is to get the drill bit centered. Start with a 1/8 inch pilot hole. Just recently did 3 out of 4 studs ona set of 360 heads.
trapster
Well-Known Member
Yea that, I think they are more likely to retain there strength threw repeated heating and cooling. But it is just my opinion and I am not sure what strength bolts were used originally.
If you drill it all the way through till the bit comes out the other side of the bolt, when and if the extractor breaks, you can just use a punch and pound the broken piece down into the head through the broken off bolt.
trapster
Well-Known Member
There is way too much taper in an extractor for that to work. Plus with my luck I would be in the water jacket for sure 
There is way too much taper in an extractor for that to work. Plus with my luck I would be in the water jacket for sure
The outside studs go into the water jackets, but the studs don't bottom out in the water jacket. It's pretty simple; once the drill bit comes out the other side of the stud, stop drilling. I have done this method in the past, so I can assure you that it works. Otherwise, if the extractor breaks, you won't be able to remove it. I'm not trying to be a smart a$$, just describing my experience with them.
swinger340
Well-Known Member
I have never had good luck w oil. Have gotten them out w heat and welding a nut to the stud, but most often quicker and easier to just drill and tap. I got a nice set of high speed carbon steel drill and taps from vendor that my work buys stuff from. Good set, makes the job a breeze.
hemi446
Well-Known Member
If the stud is sticking out before it's broken off hit the top of the stud with a hammer several times then heat the area around the stud but not the stud it self. You need the heat in the area around the stud to make sure it expands then use parifin wax and touch it to the stud it will wick down around the threads of the stud once it would cool down a stud extractor will turn the out of the head with min effort. I learned this from a Mack Truck Tech and have used it hundreds of times without much trouble
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