I just went through this at the Orlando dealership. They sold me two different sizes of circular rubber(?) washers. The parts exploded diagram looked like they both went on the bolt that holds the spin on in place. I don't see how this could be. I am assuming the small one goes on the banjo bolt for air bleeding. I will try to install them at the next filter change. I tried the copper crush washer idea last time around. None of the washers in the assortment really fit right. Let us know what you figure out.