Stale DEF
Because 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...
Forum Discussion
Lynnmor wrote:It is probably worse than that. My 2011 Silverado had a mechanisim to prevent siphoning. Basically a spring loaded door in the fill line. The Fords are likely the same. I believe it is a Govt. anti tampering requirement.rhagfo wrote:7,000 miles of day trips may be a bit too much.
Well why didn’t you do some day trip driving with it during the summer months?
There is no drain plug for the DEF, that might cost 25 cents, instead you need to siphon it out if you want to replace the fluid.
I had to remove the tank to drain mine.
DEFs shelf life varies a LOT with temperture.
