So I decided to service my calipers today to try and reduce brake drag. When I pulled the front caliper off (banjo still attached) I noticed only one piston was compressing when pulling the brake lever. It seems to be stuck in. Any tricks to pull it out without the piston puller pliers ? I sprayed some cleaner on it but can't seem to free it up. Was hoping to do this without separating the caliper halves and draining the fluid.