What was found
FUEL RETURN LINE UNDER CABIN FLOOR, BELOW COPILOT LEFT FOOT FOUND WITH VERY LARGE FUEL LEAK ON PREFLIGHT. THIS IS THE SMALL LINE THAT RETURNS FUEL FROM THE ENGINE, IT RUNS FROM THE FIREWALL TO A CHECK VALVE UNDER THE FLOOR. THE LINE WAS FOUND TO BE IN CONTACT WITH THE RUDDER PUSH PULL ROD, AND HAD WORN MORE THAN HALF WAY THROUGH (ABOUT ONE INCH LONG, AND THE FULL WIDTH.) THIS LEAK MADE THE UNDER SIDE OF THE FLOOR AROUND THE ELECTRIC FUEL PUMP AND TANK TURN FUEL BLUE. THE PROBLEM WAS FOUND BY A PILOT WHO NOTICED FUEL RUNNING ONTO THE GROUND INTO A 5 INCH DIA POOL. THE LEAK WAS STOPPED BY TURNING OFF THE FUEL AT THE SELECTOR. THE LINE MAY HAVE BEEN TWISTED INTO CONTACT AN AN ENGINE CHANGE DUE TO HOSE REPLACEMENT ON THE OTHER SIDE OF THE FIREWALL.