Sillybanshee

I just put new rotors and pads on the rear of my 93 240sx. b4 the driverside rear ebrake cable was locked up. so i got that one loose and free'd up that calb.e and that one works fine. but now after replacing both sides the passenger side rubs too much and over heats. ive pushed the piston back as far as it can probly go. idk what else to do. should i get a new rotor incase its warped or somthing? any suggestions would b good.