brake trouble
The ears of the caliper are hitting the guide pins or you have the ears aligned with the guide pins and there isn't enoughroom for the outer section of the caliper (opposite side of the pistons).
After re-reading your problem and typing this, I realize you might have stuck guide pin(s).
The guide pins pull right out of the abutment bracket with very little effort. They have a rubber boot around them to keep dirt out. If they give resistance to movement, you need to get them out clean and re-grease them.
If it's stuck, you might consider replacing the pins. I imagine the boot is torn and has allowed crap to get inside and contaminate the smooth surface on the guide pin.
I imagine your brake pads were tapered like crazy ...






