Recommended Procedure
Open the drain valve integrated in the fuel conditioning module and fill a clear container until it is half full. Close the drain valve.
Observe the WIF indicator. If the indicator is illuminated, the fuel may be contaminated with water.
Flow out of the drain should be a steady stream. Insufficient flow could indicate fuel supply or fuel system problems.
Inspect the fuel in the container. It should be clear, not cloudy. It also should be free of water and contaminants. Dyed red or blue fuel indicates off-highway fuel.
The fuel sample should not indicate evidence of waxing or gelling. Waxing or gelling in some fuels in cold weather could clog fuel filters and the fuel pump and cause restrictions in the fuel or low fuel pressure.
Some sediment and water may be present in the fuel sample if the fuel filter has not been replaced for a prolonged period of time and/or if the sediment and water have not been drained recently. If that is the case, a second sample may be required to determine fuel quality.