Checking the DEF level

[pstandiford]

Originally Posted by The Gritz Carlton

The 2017 F550 chassis has DEF level on dash readout. Only gives a percentage but that's good enough. If it hasn't been covered in this thread, many RVers use the 2.5 gallon bottles inside the store vs. the bulk at the pump. If you're not full timing it's best to not keep the tank full. It has a shelf life and bad DEF can lead to serious and expensive problems. Look up the thread on hear labeled "DEF REGEN". Lots of good knowledge there.

My F550 has an actual gauge on the display that I can scroll to. Just like a gas gauge.

[mtntrek]

Originally Posted by LAdriver

Thank you Laco for your response and explanation. I am only 2 weeks old with my Gemini... could you tell me the absolute need for Ultra low sulfur fuel vs Diesel 2? This Ultra low seems a little harder to find on a normal

All highway diesel is #2 ULS for moderate temps in the lower 48.
Off-road diesel or tractor fuel is only sold at limited outlets

[Laco]

Regarding DEF going bad, yes it does have a shelf life, which is kind of vaguely defined. I had mine serviced at the local MB dealer today, they tell me virtually the only problems they see, involve contaminated DEF, that has been contaminated by dirt, etc., and that, at least on the MB it should be topped off before the DEF light comes on, as it sometimes does not reset. With a real DEF gauge, monitoring Def levels are easily done from the dashboard display.

[simidrm]

The def pumps at truck stops have 3 different methods of preventing people from using the wrong nozzel for wrong tank.
The first is the pump has a valve inside the handle that works with the magnets in the def tank to allow flow of fluid,and second the def pump are alot smaller then the fuel, and 3rd they def handle are blue where the fuel handle are green.
Believe me I work on semi trucks as a certified after treatment technician and at least once a month we still have people who try to use water or washer fluid in the def or accidently put fuel in the def tank and all end up broke down because there is a def quality sensor in the def tank that sample the def fluid for urea concentration.

[The Gritz Carlton]

Bottom Line...don't use bulk DEF unless you're full timing or running a lot...even then you're more subject to contamination. It's better to use the sealed 2.5 gallon jugs, check the dates and don't keep the tank full if she sits for long periods of time.