This is the ******* bolt that’s a pleasure to get to because of the oil filter… I had to cut the oil filter bracket and will reweld it… Any ideas on the best approach before I drill it out?
There looks like enough bolt there to weld a nut to it. I like cutting the nuts in half to make sure I get good penetration into the stud. The heat will help loosen its grip. Breaker bar or air impact should back it out.
Yeah. Clean the top face of the broken bolt. weld a blob of weld to it. Keep welding to it. Then weld a nut to it. But don't weld down through the nut. Weld one of the corners to the blob and weld as much as you can around between the nut and the blob. Then put a punch through the hole in the nut and try and move it. Hit it with a hammer. try and move it. Do it very gently so you don't twist it off. This has worked for me lately and works better than welding down through a nut. You could drop a washer over first to protect the deck surface. I show the method in this video. It's not a head bolt but you get the idea. I did heat around it but I wouldn't in your situation. Give it a go it might just work. Mart. It starts just after the 5 min mark.
Good advice from above posters Drilling and retreading with a tap or hellicoil should be your last resort as it's likely you will have trouble getting that thread to seal later.
I've welded dozens with just a nut and also I've welded a flat washer to the bolt and then welded the nut to the flat washer. The reason for the flat washer is if the head of the bolt is flush with the block, it's easier to size a flat washer to the bolt and not have to worry about welding to the block.
I have read that you never want to re tap the threads in a flathead block. Ford used a little different thread in the block and if you chase it with a normal tap it will leak. Someone here with more flathead experience hopefully will chime in, and correct me if I'm am wrong.
everyone says weld, but does it matter whether you use tig, mig or arc (traditional) ? I would be curious to see which method you have all used. I would think that arc would send the most heat into the block, and ‘help’ move things along quicker.
I was told the same, don’t re-tap them. Also heard to use a chaser tap /thread chaser - to clean them out and others said use an original head bolt with grooves cut into it, to act as a cleaner tap. I didn’t know the thread was different, so maybe that is where the grooved original bolt idea comes from. .
My dad who worked on hundreds of flatheads in his younger years taught me to make a chaser tap with a head bolt. That’s what I will do when I get this out. I smacked it with a hammer and put on more penetrant. I will leave it soak until Sunday and then weld a nut on with a wire feeder. I like the idea of using a washer and I will put some sheet metal over the deck to protect it from spatter.
I've always used arc welding. Works best in a contaminated area where mig and tig really need clean surface. In the picture shown, I would use oxy-acet torch with a 0 tip and heat just the bolt, red hot, trying not to heat up the block. After letting the bolt cool to room temperature, it should come out with vice grips or regular pliers. The theory behind this is when you heat the bolt red hot, it expands. When it cools, it shrinks. Breaking the bond. I've removed bolts that were stuck with the heads rounded off and screw slots distorted. After using the above process, about half of them would come apart with just using my hands.
The first time i tried to weld out broken exhaust bolts from a head, i used a bunch of nuts. I quickly learned on the rest of them that you really need to lay the heat to it with the weld. Maybe arc is easier in your case, but i was working through the wheel well of a full size van with a mig. -rick
As to welding on nuts, I keep a supply of uncoated nuts for that purpose. If you don't have any uncoated nuts, an overnight soak in white vinegar will strip just about any coating or rust. I don't like the nasty chemicals released welding coated nuts.
I understand that arc welding isn't the only solution. Adapting to the situation and what works for you.
We have all tackled a variety of broken bolts such as this. The one thing I've learned is, it is worth the time to perform the process in a manner that won't leave you saying..."that didn't work, I should have done this first", thus making it a longer and more difficult operation. This particular bolt, now that it is broken, does not have a load on it but is bound by a combination of corrosion and sealer since it protrudes into the water jacket. In just the few minutes it would take to heat and saturate with your prefered penetrant, your chances of an easy extraction increase. I like to either use a crayola crayon or a few heat cycles and saturation of a 50/50 ATF/acetone solution. Both methods will get the penetration deep to where it is needed. Most times with enough stud extended above the surface it can then be turned out with just vise grips. If not, like others have said, mig weld a nut on it and turn it out. That looks like an easy one.
If you are real experienced cutting torch you can burn it out. You can’t cut cast iron with a torch but you will have to chase the treads afterwards practice on some junk cast iron first. Unless you have access to a EDM. The cutting torch is how we did it at Bud & Ken’s muffler shop years ago.
I MIG weld, that's what I have to cut the nut in half otherwise the MIG wire jumps all over the place and fills the nut but doesn't penetrate the stud efficiently. Arc or TIG would eliminate having to cut the nut down.
That is one reason I use a flat washer. Easy to weld around the outside of the bolt to the flat washer. You can then use a larger nut to weld around the bottom of the nut to the flat washer
Am I the only one that has noticed the HAMB's greatest gift to mankind is bolt extraction and the complex issue of oil changes?
I have used arc and mig. I do not have tig so cannot comment on it but the heat is what you need most of. Flat washer first then the nut with heat, a lot of heat.
You can do the weld a nut on a broken bolt in aluminum but you best leave it normalize over night then back it out. You will be surprised how east it comes out.
I’ve been reapplying penetrant and whacking it with a hammer every 2 days. I will weld on the nut this weekend and hopefully spin it out.
Sometimes working on old flatheads is an exercise in perseverance. When you finally get the broken bolt out and it's time to put it back together. Do yourself a favour and be liberal in your use of thread Sealer on the head bolts / studs. Make sure you use the genuine GM sealer. It's expensive but it works.
Weld the washer to the bolt with a lot of heat. Then weld the nut on top of it. The way you did it there was not enough heat reaching the bolt to break the bond.
That’s what I did. Burnt thru the washer in 2 spots. Entire thing was glowing orange. Then I welded the nut on around the outside to the washer and to the top of the bolt. How much heat do you suggest I get into the bolt? It obviously was enough heat because it all worked out fine.
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