crust on my

i MY CLUTCH MASTER CYLINDER & FRONT BRAKE MASTER CYLINDER , ONCE OR TWICE A YEAR GET CRUSTY FROM UNDER THE LID'S , I HAVE TAKEN THE LID'S OFF NUMEROUS TIMES AND CLEANED THEM AND THE RUBBERS , I EVEN HAD TO REPAINT MY FONT BRAKE MASTER CYLINDER LID , IT HAD GOTTEN SO FRIGGED-UP ! .. DOES ANYONE...