Diesel Emissions Fluid (DEF) System: Service and Repair

DIAGNOSIS AND TESTING - DIESEL EXHAUST FLUID

WARNING: Diesel Exhaust Fluid (DEF) contains urea. Do not get the substance in your eyes. In case of contact, immediately flush eyes with large amounts of water for a minimum of 15 minutes. Do not swallow. In the event the DEF is ingested, contact a physician immediately. Reference the Materials Safety Data Sheet (MSDS) for additional information.





1. Clean the Diesel Exhaust Fluid (DEF) pump to remove contamination or debris by the fluid filter.
2. Remove the DEF filter cap (1).
3. Visually inspect the fluid for sign of contamination or debris.





4. Collect a sample of diesel exhaust fluid from the system.
5. Test the quality of the DEF using the DEF/UREA Refractometer 94-F-OOK-108-456 available through Pentastar Service Equipment or with a litmus test paper.
a. The DEF should register approximately 32.5 percent using a refractometer or with litmus paper 9 pH.
6. If the DEF is not within specifications then the tank needs to be drained and cleaned and refilled with a minimum of 2.5 gallons good DEF.





7. Install the DEF filter cap (1). Tighten to (1) to 20 Nm (177 in. lbs).