I have a leak in my injection pump. I thought it would be the diaphragm as it leaks right under it, after replacing the diaphragm the leak continued. diesel leak is between the diaphragm and the spring through the breather hole idk what it could be! I don't think it could be a gasket bc it's leaking thru that breather hole. Any help or advice would be greatly appreciated. Thanks for your help

 

The o ring around the small fuel pin is leaking.. likely to happen if a aftermarket fuel pin is used because the little pin that rides in the fuel pin that attaches to the diaphragm is deeper. there is some good diagrams on here for the breakdown on the pump to help understand what I am trying to explain (Stickeys)