Fuel Filter | Donaldson P550943

Use a genuine Donaldson spin-on when the secondary fuel filter is due. Donaldson P550943 is a cellulose secondary fuel filter with 9-micron filtration at 99% efficiency. It is a common service part for fleet and industrial diesels and the replacement element specified for S&S Diesel Gen 2.1 CP4 disaster-prevention / bypass kits on 6.7 Powerstroke trucks.

Key features

• Genuine Donaldson spin-on fuel filter
• Secondary filtration stage
• 9 micron at 99% efficiency (ISO 19438)
• Cellulose media
• M16 x 1.5 thread
• Protects injectors and pumps from fine debris
• Used on S&S Diesel Gen 2.1 CP4 bypass kits

Fitment

• S&S Diesel Disaster Prevention / CP4 bypass kits that call for P550943 (including 2011–2025 Ford F-250 / F-350 / F-450 / F-550 6.7L Powerstroke Gen 2.1 kits)
• Many GM 6.2L diesel and fleet / industrial applications that use this spin-on size

Confirm thread, gasket size, and housing before installing. This is not a drop-in for every factory 6.7 Powerstroke or Duramax filter head.

What’s in the box

• Donaldson P550943 spin-on fuel filter

Filter head, drain, and housing are not included.

Notes & specs

• Brand/part number: Donaldson P550943
• UPC: 742330043400
• Type: secondary spin-on fuel filter
• Media: cellulose
• Efficiency: 9 micron @ 99%
• Outer diameter: 3.03 in. (77 mm)
• Length: 4.72 in. (120 mm)
• Thread: M16 x 1.5
• Gasket OD / ID: 2.76 in. / 2.38 in.
• Common crosses: Fleetguard FF5033, Baldwin BF782, WIX 33124, NAPA 3124, AC Delco TP943, Luber-Finer LFP943F, Motorcraft FD823, FRAM P3711
• S&S reference: CP4-6-7F-BP-G2-1

Lube the gasket, spin the filter on by hand, and check for leaks after start-up. Change it on the interval for your bypass kit or engine. If you need the Donaldson element for an S&S Gen 2.1 CP4 kit or a matching secondary spin-on, P550943 is the filter.