This may have been asked before. I searched but no answer found. This piece is on all the brembo's on my car and I am changing all the rotors and have already changed the brake pads to the hawk pads but on the front calipers this piece sits loose....it was tighter and didn't move with the stock brake pads. What does it do and it is necessary to leave it on?? I highlighted what I am talking about in red its the brass looking piece.
