Going to be doing pads on my car this weekend. In the past I've used a c-clamp to push the piston back enough to allow the pad to clear the rotor. I have a clamp which is capable to pushing outwards to push all pistons back in place but I've read contradicting things as to whether or not I need to open the bleeder screws to allow the pistons to go back. Is it necessary?

 

ive never opened the bleed nipple to push the pistons back...neva damaged anything yet

 

never opened a bleeder screw before for a brake job

it would just push the fluid back into the res