Ahh Fudge - Just Snapped a Thermostat Housing Bolt in my Manifold

[Jim AAR]

Tried to use an extractor and no go, it didn't budge and i didn't want to snap the extractor in there to, so I guess it's drill it out and insert a heli coil. Should have just left it alone, all I was going to do was put the original thermostat housing back on after I planed it. It was leaking so i used a cheap one awhile back which wasn't leaking.

Crap, sometimes you should just leave things alone.

I know one thing i learned, I will use grade 8 bolts and teflon tape on the bolts when I put it back together.

[Cuda Cody]

Man, that sucks. 

[EDL94]

Put some heat on it with a propane torch. Most of the time the heat will loosen it up.

[Mrbill426]

Got any (Kano) Kroil?

[Jim AAR]

I would buts its on the car and i don't like putting any flame near carbs, they don't mix very well and i don't like fire, I've burnt my hands doing silly things with electrical or flame that got a little to close to gas nearby. I had a 91 toyota 4runner that had a bad fuel pump, took it out rebuilt it and got it working, then when i was testing it, it shorted, arced and caught some gas on fire along with spilling on my hands, burnt my right hand and arm pretty bad. So i am extremely careful with any flame or arcs near flammables now.

You know what they say, ya only get burned once (literally) and then you learn.  Hopefully......

[jimynick]

If it's a steel manifold, I'd use a oxy/acet torch with about a #4 tip and heat the bolt surrounding area at least red hot. Have the stud remover ready to go when it gets that hot and you may get lucky. My old dad was a fan of quenching and would heat it the same, but then douse it with cold water to shock the grip the bolt has in the manifold. I've had some success doing that as well over the years. If it's aluminum and you have a mig, put a 3/8ths steel nut over the stub and weld down into it to the broken off stud. It won't weld to the aluminum and that usually not only gives you a new way to turn it, it also applies the heat as well. Good luck! 

[Jim AAR]

Never heard of (Kano) Kroil, but i just read about it, might work but still don't want to risk snapping that extractor in there, cause that's a true nightmare to fix, not worth it.

In my personal experience when you have a steel bolt in aluminum that has been seized with coolant, good luck breaking it loose.

[YellowThumper]

Use plenty of heat cycles to separate them. Without the top head there is no longer the upward tension.  If top is flat then also try taping it downward. Also attempty to screw in slightly prior to unwinding.

[1 Wild R/T]

Is this on your AAR?   If it is I'd do the extra work to get the bolt out without making a mess of it.... If the carbs have to come off, then they come off... If the manifold has to come off so be it....  Kroil is good, as is a torch and wax... One method that I've had great luck with is welding a nut onto the stub of the broken bolt....

[Jim AAR]

 Yeah it's on the AAR, if I had a welder I would try that but I don't so a helicoil will be what I'm doing. It should be fine. If I have any issues with it , I'll use a keensert, they are expensive but it is actually stronger than drilling it to a larger size and retapping it and they lock in.

What a pain, oh well, just how it goes with old cars.

Thanks to all for their suggestions.

[Jim AAR]

Success......

So I successfully drilled the blot out & re tapped it for a Heli-Coil.

Used red Loc-Tite on the outside threads of the Heli-Coil & let it sit for 24 hours to ensure the Loc-Tite was set.

Planed the original thermostat housing flat, put the thermostat in the housing with RTV sealant and the gasket and let it sit for 24 hours to set.

Installed the housing with RTV Sealant and let that set for 24 hours before installing it to the manifold.

Filled with antifreeze and eureka, no leaks...

[Cuda Cody]

Nice job!!!   

[Chryco Psycho]

Congrats getting it fixed !!