Donaldson P551856 Fuel Water Separator Spin-On

The Donaldson P551856 is a spin-on fuel filter water separator designed for heavy-duty diesel fuel systems. It features a 30 micron synthetic blend media rated at 90% efficiency per ISO 4402/11171. The filter utilizes an outside-in flow direction with integrated water separation capability. Key dimensions include 107.7 mm outer diameter, 143.5 mm overall length, and 1-14 UN mounting thread. Gasket outer diameter is 90 mm with 80 mm inner diameter. Bowl thread specification is 3 3/4-10 BUTT (ANSI B1.9). Primary application references the Racor R90P series. It serves as a direct replacement for OEM filters on Volvo, MAN, Scania, DAF, Mercedes-Benz, and Freightliner platforms, as well as construction equipment from Hyundai and Caterpillar powered applications.