[louielargo]

I use ATF.
Drop the caliper in a bucket with ATF overnight.
Use a C clamp to collapse it.

My grandfather would boil ATF on the fire pit and then pour it in the intake of a sized motor. He not only unsiezed the engine, he would get most running that way.

Hope some of you like the old tricks, they still work for me.

Cheers, Louie