Three Common Mistakes People Make When Using Diesel Exhaust Fluid (DEF)

Diesel exhaust fluid is a fluid that is injected into the exhaust system of a diesel engine to reduce toxic emissions. The fluid is a solution of 32.5% urea and ionized water, and it works by breaking down nitrogen oxides into nitrogen and water. Without it, heavy-duty vehicles would not be able to meet emissions standards. However, drivers make three common mistakes when using diesel exhaust fluid: putting the fluid into the wrong tank, contaminating the fluid, and storing it improperly.

Mistake #1: Putting The Diesel Exhaust Fluid In The Gas Tank

On large vehicles, like construction vehicles, the gas tank and diesel exhaust fluid port are often very close together; consequently, it’s easy to mix them up. However, the mistake can end up having very expensive consequences. Because diesel exhaust fluid contains urea, it is a caustic substance that can damage the metal of the fuel tank. One way to distinguish the two ports is by size; typically, a fuel tank will have a much larger fill hole. In addition, the two holes should have different colored caps.

Mistake #2: Allowing The Fluid To Become Contaminated

Diesel exhaust fluid only works if it is pure. Even a small amount of contamination, such as a bit of dirt around the cap, can cause major problems. To prevent contamination, all drivers and maintenance workers should be trained on cleaning the cap before filling the diesel fluid tank. In addition, drivers can test the concentration of the fluid to make sure the urea remains at 32.5% or slightly above.

Mistake #3: Storing The Fluid Improperly

Diesel exhaust fluid should be stored in a stainless steel or plastic container, and it should be kept at a temperature below 86 degrees Fahrenheit and above 12 degrees. Under optimal conditions, the fluid can be stored for about a year before it begins to degrade. However, excessive heat or sunlight will decrease its life span.

Some other tips include topping off the storage tank at the end of the day to avoid condensation build-up and changing the filters on a regular schedule. By purchasing high-quality DEF and following these guidelines, vehicle owners can get the best performance from their diesel engines.