Aimed at the problems of falling block and wear of graphite bearing of a fuel pump,in order to replace a new graphite bearing,the disassembly and installation process of graphite bearing were studied combined with the structural form of fuel pump.The decomposition method of graphite bearing was determined and a special fixture was made to remove graphite by direct turning on the machine tool.The temperature difference assembly method was proposed to install the graphite bearing,and the temperature of the temperature difference method was determined by the material thermal expansion coefficient.The processing scheme of graphite bearing of shell assembly after assembly was formulated to ensure that the size,precision and runout of graphite bearing meet the requirements.The results of 200 h durability test show that the replaced new graphite bearing has no looseness,cracks and falling blocks,and the size change is stable,which meets the requirements of size and life prediction after replacement.