Brake piston wont go back in
 

Hi all,
Went to change the brake pads on my 2000 Camry V6 model and the piston for the front ride side will not go back in fully. I already used the brake tool from auto zone and it only went in maybe a pinch. Do I need a new caliper or how can I address this issue? Do I have to open the reservoir when trying to push the piston back in?

Thanks
David M

try cracking the bleeder of the caliper

if piston wont budge... it is a seized caliper piston
rebuild or replace that caliper