broken bolt

Roy in georgia · Dec 22, 2008

I have a broken exhaust bolt in an aluminum head and have broke it twice since trying to remove it there is a little bit of it still sticking out but it still won't budge I need a sure fire way to get it out it is the only thing holding me up on putting it back together and getting paid I have a torch but don't want to use too much heat on the alum. head

MarkB_MI · Dec 22, 2008

Heat the stub of the bolt, not the aluminum cylinder head. Use a very small tip so you can concentrate the heat on the bolt. If you can get the bolt cherry red, you should be able to screw it right out with a Vise Grip.

Roy in georgia · Dec 22, 2008

I am afraid that getting the bolt cherry red will damage the head causing more problems

Anonymous-0 · Dec 22, 2008

Weld a nut to what is left sticking out, and puddle it full just dont tack it, then take wrench and spin it out.

M w J · Dec 22, 2008

Place a tight fitting flat washer over the bolt and weld the washer to it then if you can't get ahold of the washer to turn it out weld a nut to it the heat and cooling will loosen it right up

Roy in georgia · Dec 22, 2008

that's what I did and it broke off again after breaking it with a pair of vice grips. beginning to think I will have to grind it off and center punch it and drill UGH!

Roy in georgia · Dec 22, 2008

as just replied I already tried that

relaurain · Dec 22, 2008

This will work. Weld a nut to the stud, let it get cold, then heat the surounding area trying not to heat the bolt. You want the surrounding to expand - not the bolt. You can also spray like WD-40 on the bolt to cool it before screwing it out. It will make some smoke!!

DickL · Dec 22, 2008

Probly didn't have anti seize on th ebolt when installed. The steel threads have most likely picked up the aluminum and acted as a brake. Turning to screw it out will just pull all the threads out of the aluminum. If all the threads are not as of yet been pulled you could drill it out to the tap size of the bolt in the head and pick the threads out with a good scribe. If the threads will not hold after that it is time for a helicoil.

Big M · Dec 22, 2008

You are working with dissimilar metals and you may have an electrolysis problem. Steel bolt in an aluminum part. Where did you put the ground when welding the washer onto the bolt. Put it on the aluminum part and make the electricity jump through the threads. It will move some molecules around. As suggested, heat just the bolt cherry red, several times and work the bolt ever so gentle left and right turns. Add your favorite, ie. WD-40, Krol, etc in between heatings when the parts are cool and the lubricant does not vaporize.

trucker40 · Dec 22, 2008

Drill a hole all the way through the bolt in the center of the bolt.Might want to start with a small bit and work your way up.Once you get it most of the way way drilled out if its big enough that a welding rod will go down in it,weld it on the inside out with a nut on top.Weld the nut good and let it cool off.Maybe just go get a cup of coffee or something and take a 10 minute break.Squirt it with penetrating oil.If you are lucky it will shrink a little and you can screw it out.OR keep drilling until all thats still in there are threads and pick them out,or drill it out with helicoil bit for that size hole and install heli coil.

teddy52food · Dec 22, 2008

Use a hammer to gently tap it down, also use whatever style punch to tap it all 4 ways sideways with a lot of pb blaster. If you have a carbon stick like out of a flashlite battery you can heat the bolt using the welder on low or a car battery. Tap on it in all directions while it is hot. Do it again when it is cool. Don't try to turn it until everything is cool.

glennster · Dec 22, 2008

roy, see if you have a machine shop nearby, they can prolly get it out for 50 dollars or so. steel exhaust bolt stuck in an aluminum head isnt the easiest to get out. if you damage the head, what will a replacement cost. just another way of looking at it.

bthansen · Dec 22, 2008

just like the others have said weld a nut on the end of it and use a wrench to turn out, only wait until it isnt cherry red. fill that nut up and be sure to penatrate as much heat as you can straight down to the bolt so it welds to it good. yes they will break off, might take 5 nut or more. I do this with the old style radiators where they are bolted on to the top and bottom tanks.

rodgernbama · Dec 22, 2008

I would try what MwJ said. I have seen this work on broke bolts. I don't know if your familiar with antiseize. You will need to use some on the new bolts. I learned the hard way.

johndeereman · Dec 22, 2008

might try hammering the bolt with a air hammer the jarring should lossen all the rust

Roy in georgia · Dec 22, 2008

yeah I plan on using that I keep it around in a big jar copper based

Heat Houser · Dec 22, 2008

If you have a steady hand and a lot of time, drill a hole and then use a small carbide cutter to remove the bolt shank carefully working down to the threads. You will then want to carefully use a tap (rocking back and forth many times so as not to break the tap) and peel out the remaining helix. (left over bolt threads) If you mess up, there is always heli-coil.

It appears that you have heated and cooled the bolt many times so it will now be extremely hard. The cutter will cut it but it will be slow.

Anonymous-0 · Dec 22, 2008

We had a similar problem. We broke the bolt off in an aluminum thermostat housing on a Ford Van. Well we drilled a hole the put a bolt extractor in it to get it out. Well the damn extractor broke off in there and they are a tuff sucker. So we took a dremel tool and grinded and grinded till we got down far enough to use hard putty and a heli coil.

MarkB_MI · Dec 23, 2008

Roy, I know it sounds counter-intuitive, but that bolt MUST be hot to come out. You need to break the bond between the bolt and head, otherwise if you do screw the bolt out you're going to bring the aluminum threads along with it. Due to the dissimilar metals, there's corrosion in the threads and you need heat to break it down.

You will never get it hot enough by heating the head. Not only does aluminum have a low melting point, but it's highly conductive and will just sink all the heat away from the bolt.

Yes, you could damage something by getting the bolt too hot. But you WILL wreck your head if you don't.

El Toro · Dec 23, 2008

You can have your local auto machine shop to drill it out and install a helicoil. Hal

Roy in georgia · Dec 23, 2008

I will never use a ease out they make a better bolt extractor that works very good and don't seem as ready to break

scott in indiana pa · Jan 13, 2009

If you have room, weld thick flat washer with center hole slightly smaller than the bolt your trying to remove. The washer helps protect the surounding metal when you weld it to the broken bolt. Then weld a nut to the washer. This way you get a really good bite. Preferably use a big outside diameter washer so you have lots of room for welding a good size nut on. Ive worked on equipment for years, and this was one of the best tips I ever got for removing broken bolts, thanks to Dave Balthaser of Indiana Pa.

broken bolt

Member

Well-known Member

Member

Well-known Member

Member

Member

Member

Member

Well-known Member

Member

Well-known Member

Well-known Member

Well-known Member

Member

Member

Well-known Member

Member

Member

Well-known Member

Well-known Member

Well-known Member

Member

New User

Similar threads