Recently cut open an MC FL784 filter that was used as a break-in filter for the overhaul of my Ford 6.9L diesel. Changed it in only a few hundred miles due to a leak (see nearby Cut Open post). To my surprise when I cut open the filter, I found an enormous amount of grunge. I would expect to find some, since it's an overhaul, however I took GREAT pains to be clean, even scrubbing the block and heads bit with hot water and soap, using bore brushes and such on the oil galleries..
"Well," I thought, "I musta missed something."
Upon closer inspection the brown stuff wasn't a solid, it was a paste, a goo that dissolved in brakecleen. It almost completely disappeared leaving some solid particulates and metal flakes. In the photo of the rag, you can see it and it includes what I washed off the filter element as well. My tentative conclusion is that the brown stuff was either something left over from the prelube I used or some sludge or other byproduct of some kind unknown to me. Whaddya think?
"Well," I thought, "I musta missed something."
Upon closer inspection the brown stuff wasn't a solid, it was a paste, a goo that dissolved in brakecleen. It almost completely disappeared leaving some solid particulates and metal flakes. In the photo of the rag, you can see it and it includes what I washed off the filter element as well. My tentative conclusion is that the brown stuff was either something left over from the prelube I used or some sludge or other byproduct of some kind unknown to me. Whaddya think?
