Squeaking sound from brake even without apply brake. Is my caliper stuck?....
 

When I am at low speed and next to a wall or car, I can heard the squeaking sound (bounce back from the wall or car). Should I take out the caliper and rebuilt it? I already bleed the brake.

Your pad (pads) are sticking. Some of that pad glue stuff will work....
 

I had the same problem with Stoptech's on my old A4. I used some orange pad glue (not sure of the name) and it worked great. The glue basically holds the pad to the piston tightly...so it doesnt rest on the rotor.

Adam

How can glue sustain the high temp that the brake generate?

??? I didnt invent the stuff...just know it works. =)