rebuilding a 5 cylinder diesel. relacing sleeves, rings ,mains rods, head shaved, cylinder bored to match pistons. wsa looking at oil pump, cannot figure how oil is being pumped to the oil gallerys. I know how an oil pump works, but first on a mercedes engine build. There is a hole on top of the pump that seems to be a discharge port. but it is just open to the oil pan. is there a web site that any one knows where i can get a exploded view of the oil pump and related parts. I have rebuilt many a ford and chevy, but this is new to me. I dont mine asking questions or taking advice. Also should or could i rebuild this oil pump. On any new engine i have rebuilt i replced oil pump, but at 150.00 that bites the pocketbook. Help! Thanks