Just did front and back pads, rebuilt both calipers, and replaced rear master cylinder. Problem is rear pads are dragging on the rotor real bad. And rotor gets incredibly hot in two minutes of riding around the block. I pulled the caliper off, I can move the piston in by hand. Pads are wearing even and flat. I bought EBC organic pads, FA200.I got my old pads and shims out of the trash to compare. Decided to use the old shims. The pads went on easier with the old shims but not loose. Put the caliper on, installed the greased pins snug, whacked the caliper with a towel wrapped rubber mallet, as suggested, torqued the bolts, pressed on the brakemany times to seat everything. Seemed to roll much better. I think the new shims were to thick, or too much tension, and made the calipers to tight and causing them to stay pressed against the rotor too tight even after the piston stopped pressing. Make sense??? After a 10 minute ride, rear brake worked fine, I didn’t use the rear brake then for the last 5 minutes to see if the rotor was hot, but it still was.

 

I ordered a replacement caliper and pin bolts. Seems that the piston just doesn't slide freely as it should in the bore of my old one.

 

Had that same problem when I put those same pads on my bike. I took a file and cleaned up the stamping where the pads slide on the shims, also greased the shims. Helped some but not completely. After a couple hundred miles of around town, stop and go riding, everything was running cool.
I'm surprised you found the pads wearing even and flat. I found that the inside (non piston) pad had to wear at the top of the pad a bit before it could run flat against the rotor, due to the angled shape of the caliper on that side. I also think that may be part or all of the problem, as the heat went away as the pads wore in to the point where both were flat with the rotor.
Report back with how the new caliper works out for ya!

Cheers... Ben.

 

I installed the new caliper assembly and bolts. It still drags, though not as bad. I guess I will ride it for a while, see how it goes getting the pads seated. I think the inside pad is wearing like you said. Kind of frustrated, just wanted to replace the pads, found out though how bad the rear master cylinder was but this simple thing turned into a real pain in the ****. I converted my Expedition from air suspension to coil springs today, that was simple compared to these rear brakes.

 

Had same problem with EBC brake pads.95 FLSTC. Still have them in tool chest. Put HD brakes on no problem. Looking them over the brake pad area covers a little more than stock area? Rode a bit deeper on rotor.

 

seems everything is now fine after many miles. The pads had to wear at an angle, top to bottom. Had severe squealing after everything wore down but brake quiet glue seemed to fix that.