im looking to up grade i want to see what causes the pistons in the calpers to stay out while not appling the brakes ??? i jack up the car unbolted both calpers right left strated car pressed brakes pistons come out but do not retracked back into calpers fully. so put right and left calpers back on the car repeted the same test and after pressing the brakes one or the other rotors would not spin but not both at the same time after being off the brakes what is this the master cyclender going a vacume leak or bad brake lines