What should you examine for water contaminant indicators in fuel?

• A. Sediment in filters and presence of free water in the fuel
• B. Gasoline smell
• C. Color of dye
• D. Temperature of fuel tank

Answer: (A)

Water in fuel is a critical issue because it can cause phase separation, corrosion, and fuel-system problems. The most reliable way to detect it is to inspect what the fuel system shows in the filters and during drainage. Sediment in filters reveals accumulated contaminants, including moisture, which means water has been carried through the system and collected there. Free water in the fuel is a direct sign that water is present in the fuel, often visible in separator bowls or as droplets. Other options don’t reliably indicate water contamination: a gasoline smell isn’t a definite sign of water presence, the dye color just indicates fuel type, and tank temperature doesn’t reveal how much water is in the fuel.