95 E300D. I have a leak at the prefilter. I took the bolt off and removed the fuel line to have a look. The o ring on the fuel fitting looks O.K., but I will be replacing it anyway. I've searched through the threads on this forum and it appears that there are 3 o rings involved in that prefilter. Can someone give me a diagram or description of where each of them is supposed to fit so I don't skip one? The fuel seems to be coming out from where the metal housing meets the plastic part that the fuel fitting snaps into.