[kitchen]

Kroil, heat on the nut only, a 6 point socket on a breaker bar, then, while tensioning the bar, smack it with a dead blow hammer.

I'm assuming this a nut and bolt situation. If the above fails, get a nut splitter. You should replace all the hardware - springs, clips, bolts, boots, etc.- any time you dismantle a critical component, so don't worry about effecting heat treatment because your tossing them anyway.

[Paul R.]

No, this is a “pin”.

I don’t have an exact image, but, at this point, I believe it is a “hex head”: visualize a bolt head with immediate threads, and then a “smooth” pin that goes on through a boot and into the caliper body, ending inside the body. No nut to split.

What bugs me is that if the only threads are just “under” the hex head, 3 days of PB Blaster should have some effect. It may not be the “best”, but in the past I’ve found it to be fairly effective. I may try the acetone + ATF next...