Is this how to get a caliper to retract? 🤣

[Donald]

What is the best method to remove corrosion from the caliper bore and sides of piston? Fine sandpaper, steel wool, wire wheel on Dremel?
All of the above?

You wipe down the piston and if it does not look pristine replace it. Never wire brush or sand. If it's got rust or pitting then the plating is gone and the piston needs to be replaced.

The caliper bore can be resurfaced with a brake cylinder hone.

 

[Brybo86]

No after pic? Keep an eye out for leaks at the piston as no matter how well you removed the rust, it likely has microscopic edges that will scuff the seal.

Sorry no after pic, my hands were filthy didn't want to touch my phone.

There were a few tiny dots on the edge of piston.

Cylinder bore was pristine.

I can't imagine they are currently more abrasive than the piston condition that was in there for the last 30k miles right.

How much does the piston move when pedal is pressed? 1/32 to 1/16 Inch?