CougarnewbieExplorerDec 08, 2020Stale DEFBecause of Covid my F-350 6.7 diesel has been garage kept since February. The DEF tank is full. DEF has a shelf life. Should I be concerned enough to consider draining the old DEF? My first diesel. T...Show More
Old-BiscuitExplorer IIIDec 08, 2020Shelf Life ...2 yrs in a SEALED ContainerSave bet ---- drain and refill with NEW