broke a bolt off in intake on thermostat housing

[1972BlueC20]

So I broke an old rusty bolt off in the intake while changing my thermostat. It's about a 1/4 down in the hole. No bolt sticking out to grab onto. What should I do? Easy out??

Please help!!!!

[Dunenutt]

Carefully punch it in the center, drill, and easy out it.

[Pick]

Soak it good with Kroil or PB Blaster first, then try an easy out. A little bit of heat might help it let go as well........but be careful how much and how quickly you heat it (or cool it) so it doesn't crack.

If you can get ahold of a left-handed drill bit, it might grab and do the work for you without having to use an easy-out.

Drill carefully and don't go too deep. (obviously) The straighter you can drill it, the better the odds of a successful outcome. (less tendency to break drill bits and/or easy-outs in the stuck bolt)

I hope some of that helps!

There are more tricks to getting broken bolts out but hopefully the simple stuff will work for you!

[1972BlueC20]

The guy at Lowe's gave me something called grabit, is that similar to easyout? They don't have easy out. It says on the package removes damaged screws.

[trac209]

Depending how much threads are exposed you may be able to just use a stud in there and install a nut over that. I've done that for quick fixes that soon become permanent lol. Iron or aluminum intake? If aluminum you need a bit more threads.

[1972BlueC20]

There is no stud sticking out.

[dfrank]

If the bolt broke off due to being rusty then it most likely won't come out with and easy out. Your best bet is to just drill the bolt out then run a tap down the threads. If the easy out breaks in the bolt well then good luck drilling that out unless it is a really shi**ty easy out.

[1972BlueC20]

Here's a pic of what happened. Th bolt on the left broke off.

[hamjet]

I myself would try to drill as close to dead center as possible down maybe 3/4 inch a little under the diameter of the bolt, get the antifreeze out of the intake so it wont act as a heat sink, then take a punch, hit the bolt to shock the threads, run a torch around the circomference of the bolt hole just before it turns red, but not enough to get the bolt too hot, and then do the easyout thing... I don't know what the grabbit thing is, but it should be an easyout.. if that doesn't do it, drill larger till you just touch the threads and use a pick to get the threads out...

[cdowns]

i'd dump that cast iron manifold and install a new shiny aluminium one

[trac209]

Originally Posted by 1972BlueC20

There is no stud sticking out.

I mean put a stud in on top of broken bolt but looking at your pictures you dont have enough threads showing.

[carp1329]

Originally Posted by cdowns

i'd dump that cast iron manifold and install a new shiny aluminium one

This is what I would do too.

[1972BlueC20]

Ok so I'm screwed, can't get the bolt out. I drilled most of it out about a half inch down. Problem is now the hole is slightly bigger. Could I tap the hole and re thread 1 size bigger than the original 3/8 ???

[Lattimer]

Originally Posted by 1972BlueC20

Ok so I'm screwed, can't get the bolt out. I drilled most of it out about a half inch down. Problem is now the hole is slightly bigger. Could I tap the hole and re thread 1 size bigger than the original 3/8 ???

You can do that. I would check how deep the other hole is, and drill the same depth. Then tap it and drill the thermostat housing hole a little bigger to fit the new bolt. Shouldn't hurt anything.

[1972BlueC20]

Cool, Do you happen to know what the next size up from 3/8 would be??

[BLT gmc]

Helicoil time.

[1972BlueC20]

What's helicoil?

[Lattimer]

Originally Posted by 1972BlueC20

What's helicoil?

Its a thread repair device.

Amazon.com: Helicoil 5521-6 3/8-16 Inch Coarse...
You can find them in hardware stores and better auto parts places, as well as online.

You drill the hole out, thread it, and put the helicoil insert in. Then your original size bolt fits in the insert. They work very well. If you are concerned about keeping the same size bolt as original, its the way to go. Otherwise, drill and tap and go up a size.

Next size up is 7/16 if you just want to use a bigger bolt. Look up the appropriate drill for a 7/16 tap before you drill any more.

[Lattimer]

Also----don't feel bad about breaking that bolt. the more you work on old stuff, the more you will break. After a while, you become a master of all of the many repair techniques available for just these type of situations.


Another thing to think about-----this is usually the point where I tell my wife I need a new manifold because of the broken bolt, and I stomp around and look angry for a while until she feels sorry for me and tells me to go by whatever I need.... Just sayin!

[Mikeeal33]

Same exact thing happened to me. I ended up drilling it out completely and tapping with a 7/16". Worked great no leaks. Good luck.

[Turbo1dr]

I NEVER try to drill a broken bolt out....EVER. It mostly always ends up with a off-set hole or threads ruined. If you have access to a MIG welder, you can mig weld a spot in the center of the broken bolt...wait 2-4 seconds and then mig on top of that mig weld until you build up enough welds to have a short stud sticking out. Thay way, you can grab a pair of channel-lock pliers onto the stud and then, screw it out. The hot mig weld will penetrate the broken bolt deep enough it will free up the bolt. The secret is not to try to turn the bolt only one direction to get it out. If the bolt stops turning to the left, stop, then, start to turn it to the right. Repeat this back and forth motion until you get the broken bolt loose enough it will come out freely. I've don't it this was so many successful times it's crazy.

If the weld breaks off the broken bolt, just re weld another stud on it and try again.

[1972BlueC20]

Well no stores in my are have a 7/16 tap unless you buy the whole set which is $80. I guess I'll have to go 1/2.

[Jake1971]

Originally Posted by cdowns

i'd dump that cast iron manifold and install a new shiny aluminium one

That's what I did. Edelbrock Performer all the way! (I traded a pair of rusty headers for it )

[1972BlueC20]

Well my intake cracked trying to tap it. So new intake it is. Lol. Any good threads on removing and installing a new intake?

[dfrank]

Originally Posted by Turbo1dr

I NEVER try to drill a broken bolt out....EVER. It mostly always ends up with a off-set hole or threads ruined. If you have access to a MIG welder, you can mig weld a spot in the center of the broken bolt...wait 2-4 seconds and then mig on top of that mig weld until you build up enough welds to have a short stud sticking out. Thay way, you can grab a pair of channel-lock pliers onto the stud and then, screw it out. The hot mig weld will penetrate the broken bolt deep enough it will free up the bolt. The secret is not to try to turn the bolt only one direction to get it out. If the bolt stops turning to the left, stop, then, start to turn it to the right. Repeat this back and forth motion until you get the broken bolt loose enough it will come out freely. I've don't it this was so many successful times it's crazy.

If the weld breaks off the broken bolt, just re weld another stud on it and try again.

That is why you use a center punch to mark the center of the broken bolt and then drill and tap. You have to use a drill bit that is slightly smaller than the bolt though.