What Happens If You Put Water In Your Def Tank - Why Is World Hunger An Environmental Issue Quizlettimeline Friends2 Diesel exhaust fluid (def) is added to diesel to help convert nitrogen oxide (nox) emissions into nitrogen and water. This helps diesel engines meet the strict emissions. To drain a def (diesel exhaust fluid) tank, wait until the tank is completely empty and then rinse it out with warm water. Once cleaned, refill the tank with fresh def. I see the benefit from this as being that if you get def crystallization in your tank and lines, you could potentially flush the system with tap water instead of replacing everything.
Why Is World Hunger An Environmental Issue Quizlettimeline Friends2