I have Wilwood 4 pot in the rear, and this only seems to happen on the driver side rear caliper. If I press on the brake you hear like a creaking squeak noise definately coming from inside the caliper. The car doesn't have to be moving

Does anyone have any idea what this could be? They're fairly new.

 

I'm having the same problem with my stock Brembo's..After I turned my rotors and changed to Nismo pads...

 

A combo of pads rubbing the guide plates and caliper deflection would be my guess.

 

bump its gotten worst now, all 4 calipers do it.

its a creaking noise from the caliper piston...