ive done brakes on multiple cars including my 01 z28 with out any problems but when putting on new rotors and pads on my 94 z28 i encountered some issues with the back brakes.....i cant get the piston to derpress evenly,

..i screwed around with this for a while in the 100 degree weather and came to the conclusion i need help. i tried adjusting the allen key on the one side... ive tried disconnecting the e-brake, nothing will work, i even tried to put the old pads back on temp. but it wont slide over the new or old rotor.... i need help any little piece of advice is greatly appreciated...sry for the crappy pic i used my cell