John...I recently gave that a try when swapping a downpipe. The nuts on the converter did come off easier than I thought they should...but who knows.

Well.....the propane torch wasn't giving enough heat, so we finally got out the oxy-acetylene cutting torch and heated the bracket till it was red hot, and I mean RED hot. Still took a cheater bar and a good amount of grunt but we got the bolt out. And yeah, you gotta drain all the brake fluid and get things out of the way. I was replacing the caliper anyway so I was not worried about damaging it. I was not too thrilled that we had to put so much heat on the bracket, so I don't want to recommend it.

The heat will only tend to soften hardened parts.

As long as you don't chill the unhardened heated parts very slowly, then will not become brittle.

It'* a good trick if you want to bend or deform a metal part. Heat it up cherry red and then pound on it. Forging at its best.

I haven't tried the stuff yet, but it'* made by a reputable company, and sounds like a better idea than heat/open flame near flammable materials/liquids

Well, got back from vacation and went to work. I removed the caliper first to get stuff out of the way and then I used an oxy/mapp torch which did the trick. Thanks for all the suggestions.