Rotors rust, especially if you have open wheels. See pic.I can tell my fronts are working because the rotors are clean from the rubbing. The rears are a bit rusty and the rust never gets rubbed off.
The parking brake adjusts the rear disks.My parking brake cable snapped a year or two ago. It kind of dangles down unless I keep it in at all times. It doesn't actually grip at all. I was actually wondering if the parking brake is an integral part of rear brake functioning.
If one side wears more than the opposing pad, then it is not the cailper at fault. It is the guide pins on which it slides. And remember, the parking brake adjusts the rear calipers.Had it checked out. Apparently it's seized calipers. The inner pads are worn out but the outer pads have 3/4 life. He'll try to fix the calipers or replace them. Also, I'll be getting rotors and pads.