[Dave W]

Ford says every 3rd oil change though the info center will probably tell you to do it sooner. I generally do mine after the second oil change(~15K miles) though the last time was 20K+. The primary filter housing had no dirt or water so suspect that these mileages are CYA. An that Ford primary filter - you had best have a spare plastic cover, WIF sensor and drain on hand since that bottom nut likes to break off regardless of how gentle you are as I found after a diesel fuel bath and a few gallons of dumped fue that ended up in my tractor. You better believe that those Bosch HP pumps are fragile, regardless of truck brand. They will not tolerate much in the way of dirty fuel.