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I have a fleet of Cummins 5. 9 here. Several have leaking valve cover gaskets. In particularly it's the rubber seal atop the cover, surrounding the hold-down cap screw. I have tried cleaning them and also silicone to no avail. Other than replacement, the next best thing is removal and flipping them around. This has resulted in a fresh sealing surface and no leaks so far.
Scott
I have a fleet of Cummins 5. 9 here. Several have leaking valve cover gaskets. In particularly it's the rubber seal atop the cover, surrounding the hold-down cap screw. I have tried cleaning them and also silicone to no avail. Other than replacement, the next best thing is removal and flipping them around. This has resulted in a fresh sealing surface and no leaks so far.
Scott
