Description Reviews MINI Cooper S Coolant Bleeder Valve. This item (#4 in the photo) is needed because of use over the years from coolant flushes, the bleeder screw can get chewed up as well as getting broken off inside the fitting. This is not a part that you're going to be able to pick up at your local parts store, and it's needed to bleed the system correctly. Comes with new center section as well as an o-ring and bleeder screw. This is the high point in the cooling system. New Aftermarket Part.