I just replaced the water seperator filter cover, the one that has the drain plug located bolted to the frame under the drivers side. The reason, the threads were gone. My question because the truck is not that old, the filter case is aluminum and the drain plug is of hard metal. Does this set up and electrolysis field? A soft metal, aluminum, a hard metal the plug, and diesel fuel the liquid. The aluminum is the soft sacrificial metal and the weakest point are the threads. I'm note a chemist but I think Ford has a problem or atleast I did, Any others out there?