Rear left disc brake problem

So this just happned two days ago but mostly yesterday. I noticed a noise coming from the rear of my car and thought that it was a wheel bearing. But it sounded like the breakpad was rubbing. So I let off the throttle and the noise continued. After pulling over and putting my hand close to the rear left rim I could feel pretty good warmth radiance and so I took a cap of water and splashed it onto the disc and it evaporated so fast I didn't even have time to look at it. So I let it cool off and drove home and it didn't make the noise because I was driving on slow roads and it was a short drive. I stopped at one stoplight and I was letting go of the brakes slowly and could feel the rear knocking bad as if though the caliper piston wasn't letting go. That could explain why my brake was heating up so much. Any advice?

I took off the wheel yesterday and I'm pretty sure that the piston is not letting go all the way, maybe some debris is in there. So I bought brake cleaner and am going to try to clean it out. When the piston works like it’s supposed to then it doesn't rub, but when it doesn't then the pads rub bad. The pads have a lot of material on them so they are good, thought they might be worn out.

Did the brake cleaner work?

TS out

No. I'm gettin the thing fixed and will let you know what it was but I use the brake cleaner on the rotor to keep it cool so that I can get to the shop.

so, the caliper is dragging. So I need a new one. Went online to look for one and went to about 5 different sites but didn't find no left rear calipers. Anyone know where I can find one?

Went to autzone cuz its the only place open late and has most parts. Ordered my caliper for $100 with a $50 core charge and bought front brake pads, they don't have rear pads :screwy: So I stop by pepboys on the way home and got rear pads. Paid $240 for everything but will get my $50 back for the core.

The caliper I got had the parking brake mechanism on it and my parking brake is in the drum of the rotor so I took it back to autozone and the guy looked on the computer and the part number for the caliper for the 2000 sonata is different so I had him order that.