What's the deal with these? I get that it screws the piston back into the caliper to put new pads on, but why does the piston screw at all? Aren't hydraulic brakes supposed to be self adjusting? How does the piston get unscrewed, am I supposed to go in there now and then and unscrew it a little? What happens if I never screw it at all and let the piston take up the slack? This all seems like boomer shit that shouldn't exist any more.