2001 Toyota Avalon • 149,000 miles

I have a 2001 Toyota Avalon. A couple weeks ago I hit the brakes and they started grinding. I had no indication of an issue before then. It didn't happen again until about a week later and then it started grinding really bad all the time (rear brakes). Then it started grinding whether or not I was pushing the brake (not as bad as with the brake depressed).

So, I am trying to replace the rotors and pads myself to save some $. Problem is, I've changed one side where the rotors were gouged, and I had a hard time getting the pads into the clip that holds them in place. And when I pushed the brakes to prime the brake line, I couldn't push the pedal down more than one or two times. And the brake is locked up.

Do I have a bad caliper? Brake line? Just need more grease on the caliper pins? Brake pads wrong size?

Please help.
December 5, 2012.

Pins may be frozen or the brake hose is collapsed not releasing the pads.