In the operation of an internal-combustion engine, cleanliness is of paramount importance. This is especially true in the handling and care of diesel fuel oil. Impurities are the prime source of fuel pump and injection system troubles. Sediment and water cause wear, gumming, corrosion, and rust in a fuel system. Even though fuel oil is generally delivered clean from the refinery, handling and transferring increase the chances that fuel oil will become contaminated.
Corrosion often leads to replacement or at least to repair of the part.
You must continually take steps to prevent water from accumulating in a fuel system, not only to eliminate the cause of corrosion but also to ensure proper combustion in the cylinders. Centrifuge all fuel, and drain the fuel filter cases periodically to prevent excessive collection of water. Water in fuel will cause irreparable damage to the entire fuel system in a short time. It corrodes the fuel injection pump, where close clearances must be maintained, and also corrodes and erodes the injection nozzles. The slightest corrosion can cause a fuel injection pump to bind and seize which, if not corrected, will lead to excessive leakage.