Donaldson P550847 Fuel Water Separator — Spin-On Twist&Drain

Protect diesel injectors, pumps, and fuel systems from water, dirt, rust, and other contaminants with the genuine Donaldson P550847. This 10-micron spin-on fuel/water separator uses composite media and Donaldson’s Twist&Drain design so you can drain collected water quickly without removing the filter.

Water in diesel fuel causes corrosion, microbial growth, poor combustion, and injector wear. The P550847 is built to remove both free and emulsified water while capturing fine particles. It is a common replacement on Caterpillar-powered Class 8 trucks and related heavy-duty applications.

Key benefits

• 99% efficiency at 10 microns (SAE J1985)
• 95% emulsified water removal
• Twist&Drain valve for fast water drain-off during service
• Spin-on design for quick change-outs and less downtime
• Durable composite media for consistent flow and longer service intervals
• Direct-fit replacement for many OEM and aftermarket numbers

Specifications

• Part number: P550847
• Type: Fuel filter / water separator
• Style: Spin-on, Twist&Drain
• Outer diameter: 3.66 in (93 mm)
• Length: 7.64 in (194.1 mm)
• Thread: 1-14 UN
• Gasket ID / OD: 2.44 in / 2.83 in (62 mm / 72 mm)
• Media: Composite
• Particle efficiency: 99% @ 10 micron
• Test standard: SAE J1985
• Emulsified water efficiency: 95%
• UPC: 742330195000

Related Donaldson parts often used with this filter include Twist&Drain bowl P569758 and various fuel head assemblies. Always match the head and bowl to the application.

Typical applications Used on many heavy-duty diesel trucks and equipment with Caterpillar C7, C9, C10, C11, C12, and 3176 engines, including:

• Freightliner Century Class, Coronado, Argosy, Condor, B2, FB65, and related models
• Kenworth W900, T800, T300
• Peterbilt 335, 340, 377, 387
• Ford F-650 / F-750
• Select Caterpillar equipment and mining applications (verify head spec)

Fitment varies by year, engine, and fuel-filter head generation. Confirm against the existing filter, head thread, and gasket size before ordering.

Common cross references This filter replaces or is equivalent to:

• Caterpillar 175-2949 / 1752949
• Baldwin BF1268
• Fleetguard FS19683
• WIX 33005 / 533005
• NAPA 3005
• Luber-Finer LFF8030
• FRAM PS9330
• Hastings FF1182
• Carquest 86005

Some catalogs list a later Donaldson number (P551743) as a supersession—verify current application data if you are replacing an older unit.

Genuine Donaldson filtration helps keep fuel clean, reduces injector and pump wear, and supports reliable operation in fleet and vocational service. Always follow the engine manufacturer’s service interval and drain water regularly.

This listing is for Qty 1 filter.