Donaldson Fuel Filter & Water Separator Spin-On (P551854)

The Donaldson P551854 is a spin-on fuel filter and water separator cartridge engineered for heavy-duty diesel fuel systems. It removes water and fine contaminants before they reach sensitive components, helping protect injectors and fuel pumps while ensuring reliable engine performance under demanding conditions.

Features:

• Spin-on cartridge style with integrated water separation

• High filtration efficiency for particulate removal and water separation

• Durable construction for long service life in heavy-duty applications

• Thread size: 1-14 UN, Outer diameter: ~4.33" (110 mm), Length: ~6.11" (155 mm)

• Helps prevent fuel system corrosion and injector wear

Applications:
Ideal for heavy-duty trucks, off-road equipment, and diesel engines requiring fuel cleanliness and moisture control. Common in applications needing combined fuel filtration and water separation.

Cross References:

• Fleetguard: FS20028

• Baldwin: equivalent part numbers

• Racor: R90S style spin-on fuel/water units

• Various OEM spin-on water separator equivalents