My rear right brake is dragging after I replaced the pads. Initially, I thought it was a defect pad and so I returned it and got a different one/brand, but it still drags on the same side.

• When I put the old worn pads back on everything seems fine.
• Caliper piston glides back nicely and smoothly when I compressed it to install new pads
• I cracked open the bleeder valve to bleed the brake so I'm sure I din't push any contaminants back into the system.
• I lubed caliper pins like I always do. They move freely when inserted.
• I checked and adjusted parking brakes to ensure the rotor spins freely, but as soon as I install wheel lugs it seizes again (in fact, it binds if I only install the lugs nuts without the wheel)
• Brake fluid shoots out OK when brake pedal is depressed and there is no sign of pressure lock when I release the brake.

Any thoughts about what could be binding? It must be mechanical interference because when this happened with the first set of pads I heard whoob-whoob-whoop sound as I took it for a test drive. I can't hear a distinctive sound now, but it still binds and heats up.

 

Warped rotor?

 

I swapped rotors and the problem stayed on the same side, but that gave me a moment to pause and rethink what else it could be. It turned out to be the lower caliper pin - the rubber bushing at the tip of the pin was a little deformed and binding.