Diesel Exhaust Fluid is nonhazardous solution which is 32.5% urea and 67.5% de-ionized water. DEF is spray into the exhaust stream of diesel engine to break down dangerous NOx emission in to harmless Hydrogen and Water. You can find this technology on recent CAT, Volvo construction equipment and other construction machine manufacturer.

Base on our research among Volvo CE and CAT customer the most common problem we found is:

  • Putting DEF in to Diesel fuel tank
  • DEF contamination
  • Improper holding of DEF

First problem and the most common one is putting DEF in fuel tank. Diesel exhaust fluid is emission solution to reduce NOx emission in the Tier 4 regulated diesel engine. DEF should never mix with diesel fuel in construction equipment or any other machine if this happened, I should tell you prepare yourself to buy many diesels engine replacement part spend thousands of dollars to back your machine on the job site so be careful.  In this case be inform the cab on the DEF tank is usually blue and remember fill house for DEF tank on diesel engine is always smaller than fuel tank. It is critical if you did not know you choose right tank to fill the DEF, flash your fuel tank and clean it in proper way. Just teach your operator the difference between Fuel tank and DEF tank. Ask your operator if they fill the fuel tank with DEF inform machine technician as soon as possible before running the engine.

Avoid contamination, yes, it is the best solution. Diesel Exhaust Fluid is extremely sensitive to contamination. Purity is critical to DEF to work properly. Contamination around the cap can make their way in to the tank and make serious damage to your engine. Best solution to that is to ask your machine operator or service team to keep that area clean also it is important to ask your heavy equipment operator and technician, used container which hold different type of fluid is not suitable to hold machine DEF. if you use contaminated DEF your engine will automatically shutdown and your fleet up time decrease dramatically.

Proper storage is another factor which may cause difficulty.  Store DEF in a cool and dry indoor place is preferable. DEF will degrade in storage in long time but if you keep it in 12 F to 86 F it is possible to use it for one year. DEF will freeze in below 12 F and could be slushy, but it doesn’t affect quality or performance. If you need to store it in cool place don’t forget you need to keep it in expandable storage.

As you can see it is not difficult to deal with DEF and SCR technology. keep it clean, store it in proper place. Keep in mind change the DEF filter regularly base on machine service manual and don’t mix it with diesel fuel.