The process used to identify and diagnose leaks in the fuel system of a vehicle or any other equipment that uses a fuel line. The process used to identify and diagnose leaks in the fuel system of a vehicle or any other equipment that uses a fuel line. The process used to identify and diagnose leaks in the fuel system of a vehicle or any other equipment that uses a fuel line. The process used to identify and diagnose leaks in the fuel system of a vehicle or any other equipment that uses a fuel line. The process used to identify and diagnose leaks in the fuel system of a vehicle or any other equipment that uses a fuel line. The process used to identify and diagnose leaks in the fuel system of a vehicle or any other equipment that uses a fuel line.