Testing Diesel Exhaust Fluid (DEF) (Final Tier 4/Stage IV)

H106105-UN-06NOV12

IMPORTANT: Using DEF with correct concentration of urea is critical to engine and aftertreatment system performing correctly. Extended storage and other conditions can adversely affect DEF solution concentration. Testing solution concentration is only way to confirm that DEF is at correct strength.

Any time DEF quality is questionable, check DEF urea concentration. DEF urea concentration should be checked when vehicle has been stored for expended period of time or if it is suspected that vehicle or stored DEF fluid has been contaminated with water. DEF urea concentration should be checked when vehicle has been stored for expended period of time or if it is suspected that vehicle or stored DEF fluid has been contaminated with water.

Test DEF urea concentration using a refractometer. This special tool is available through your John Deere dealer. Follow tool use instructions to obtain measurement. Correct urea concentration is 32.5 +/- 0.7%. If vehicle DEF urea concentration is found to be outside specification, drain vehicle DEF tank, flush with distilled water and fill with new or known good DEF. If stored DEF is found to be outside specifications, discard DEF and replace with new or known good solution.

If DEF quality is in question, and a refractometer is not available, physical examination of a sample may help determine condition. Remove a DEF sample from tank or container and place in a clear vessel. DEF should be crystal clear with little to no smell. If DEF appears cloudy, has a colored tint or a profound ammonia smell, it is likely out of specification and should not be used. In this case drain tank, flush with distilled water and refill with new or known good DEF. After completing tank refill, check DEF concentration.