Technical Stuck bolts in carb

Any suggestions for freeing steel banjo bolts stuck in a pot metal carb?

SU HD8 carb
In one carb I tried Kroil and PB Blaster, an HF sonic cleaner (useless), and heat with Oxy-MAPP and finally broke the float bowl lid trying the free it. I can get a replacement, but I don't want to just keep throwing money at it, and the final carb has 2 stuck banjos.
I was able to free up the idle adjustment screw on the other carbs with the above methods, plus boiling it in water.
A working set is worth decent money, so I don't want to just give up on it.

More heat? Acetone+ATF? An impact would probably break it.

 

Have you tried tapping it with a hammer?

 

Yes. Not hard, but from fairly good whacks to small taps while trying to tighten/loosen the bolt.

 

Maybe one of those hand impacts drivers that you use a hammer on.

 

May need to drill it out. Pot metal can litteraly fuse to steel components.

 

Might take an impact wrench and set it on a very low setting, almost nothing, and let it kinda “ vibrate “ the bolt for a while. Might combine that with your heat. Also you might try concentrating the heat on the bolt, to expand the bolt , then let it cool before trying to turn it, several times. Lastly , if you can replace the banjo connector, you might drill it out to relieve pressure .




Bones

 

Sometimes it's hard to tell where the actual "stuck" part is. Is it the threads in the body, or is the bolt stuck to the fitting. I've had some luck , just concentrating heat, with a small flame, on the exposed part of the bolt(head), and letting the heat soak in to it, several times. Some of the guys at work, will quench it, and the shock helps release the bond. I will, spray it with some good rust penetrant- PB or acteone/ATF.
Just some suggestions.

 

last one i did was on some side draft Webers. I put the carbs in a vice to hold it. Then heated the base where the bolt threads in with a Mapp gas torch, then had a wrench on the bolt pulling to loosen the bolt while tapping the bolt head with a small ball peen using the round end to hit the bolt and not the wrench. Took awhile but one came out perfect, the other came out and took some threads with it. I found a thread insert repair kit on line for weber inlets and took care of the messed up threads. Good luck with it, those can be a real bitch if you have to get them out.

 

Heat the screw head and drip wax at the base of the head

 

It doesn't actually fuse, but when it's molten and surrounds a dissimilar metal part, as it cools, it shrinks so tightly, it's like a bond. I've done it many times. Works well, but depending on the stress of said part, one can use a higher grade meterial and not need the other at all.
Just food for thought...