Heat Exchanger broken screw

[djousset]

Thx for all the tips. I’ve tried PB Blaster, heat, muscle and hammer encouragement. No go. The stud on the front side is also stuck (threads are stripped)
I don’t know how to weld, and don't have drill/tap tools, the extractor didn’t work so…..
it’s now off and in the back of my car. Time to seek outside help.

[pesarsten]

Can you remove the cast heat exchanger so you can bring it to a machine shop?

[Rumrace]

Nut n bolt extractors come in kits with 4 sizes. Canadian Tire and in USA Pep Boys and Western Auto. A small screw requires 1/8 cobalt drill centre point then small toque bar 1/4 drive and the little extractor and it’s gone. The small one will remove the screw without the head

[Rumrace]

I have a micro set and removed a 4mm broken thread on a stepper motor.
I’ve also used them to extract broken head bolts from aluminum and cast iron blocks.
Broken screw on sanction bases. Considering how brittle stainless gets sitting in wet teak for years it’s a tool every boat box needs.
But 1/8” depth on number 6-8 screw

[bwalsh]

I am attempting almost the same exact extraction on my spare heat exchanger but i am removing steel from aluminum. I broke all bolts on one end/ all corroded and stuck in there. I'm down in MA (not too far) and have a TIG welder to attempt the nut welding job. Let us know if you come up empty, I may be able to help being not too far away.

[djousset]

I did it. The next size up extractor, penetrant, a T handle tool and patience, and it is out. And the internal threads look great. I'm very relieved. Now to reinstall the heat exchanger properly....

[Scubaseas]

Originally Posted by djousset

I did it. The next size up extractor, penetrant, a T handle tool and patience, and it is out. And the internal threads look great. I'm very relieved. Now to reinstall the heat exchanger properly....

Well done. Put 242 blue Loctite on the threads and antisieze compound on the shaft of the bolts. Makes it ever so much easier to remove next time. Don't use copper anti size if there is aluminum involved.

[Rumrace]

Love Blue. Safe as milk. I always run a cleaning tap in the engine threads. Just so I know fresh loctite has no debris to stop it from covering the whole thread.

[Ninedotsix]

Originally Posted by Scubaseas

Well done. Put 242 blue Loctite on the threads and antisieze compound on the shaft of the bolts. Makes it ever so much easier to remove next time. Don't use copper anti size if there is aluminum involved.

Congrats on patience and careful effort getting that slug out, you did.
"Hold your mouth right and you can do it", so they say.....
~ 9.6

[Celestialsailor]

May I suggest not using hex nuts to reinstall...but rather grade7 or 16 threaded studs. Very unlikely they would ever snap.

[Spot]

Originally Posted by djousset

I did it. The next size up extractor, penetrant, a T handle tool and patience, and it is out. And the internal threads look great. I'm very relieved. Now to reinstall the heat exchanger properly....

Awesome! Such a good feeling after the letdown of a broken fastener...

[djousset]

Looking into anti-seize/ blue loctite now. The manual makes recommendations on where to use each. Good tip on the rethreading, thx.

The stud for the cap on the forward end of the exchanger does have buggered threads (and it doesn't want to budge for replacement) so I'll clean/rethread that and hopefully the nut will slip right back on.