I've edited the pic with
PINK ARROWS pointing at the clip so you can see better. Look at the metal clip inside the piston around or embedded in the rubber boot.
Do I remove that? I've never seen it before and I'm wondering if that is there to hold the boot in place along the piston as it moves up and down inside the caliper housing. Sounds kinda dirty doesn't it? lol - It would make sense as an upgraded design to have a clip holding onto the piston seeing as the sides of my old pistons were really funky which is one reason why I'm pretty sure the brakes were sticking.
