inside my fuel pump
 

ive had problems with fuel pumps on my 88 300se a few different times now ..so i decided to cut it open and see just what is going on. granted this is an aftermarket pump but im assuming they work the same .. i have a bosch in now and if she dies ill do the same to make sure its the same issue ..

the one with the arrow is pointing to a slot and in that slot a tiny pin is suppose to be in there.. it is there to spin the mechanism when the pump is activated.. well over time it slightly bent and eventually broke .. hence the loud buzzing noise as the parts arent snug anymore ..then one day poof buh bye



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