Failure analysis of fuel pumps used for diesel engines in transport utility vehicles

Abstract

Present work deals with the failure analysis of fuel pump in transport utility vehicles. The fuel pump assembly failed at 70536 km. Various types of failures in pump and its different components are analyzed. Failure mode and effect analysis (FMEA) of the acquired data has been carried out. The pump components with substantial contribution in failure are determined using risk priority number analysis and the failure causes are postulated. Using scanning electron microscopy (SEM) for pump parts as rollers and cam plates the types failures are observed. Presence of water in fuel tank indicated the reason for rusting of bottom surface of tank. Pitting failure due to rust particles has been identified in pump parts after SEM observations. Energy Dispersive Spectroscopy (EDS) of pump parts has also been carried out to identify levels of unnormalized constituent elements responsible for failure. From EDS presence of oxygen responsible for oxidation reaction with iron is identified. Significant percentage of oxygen at different locations indicated the presence of moisture in the system. Remedial measure to avoid pump failure has been suggested in present work.