Description
Fleetguard FS1065 spin-on fuel/water separator for Cummins ISC 8.3L, ISL 9.0L, ISB 6.7L, and L9 diesel engines, manufactured by Cummins Filtration. Uses StrataPore synthetic media to deliver 98.7% filtration efficiency at 10 microns (SAE J1985) and 95% removal of free and emulsified water, protecting high-pressure common rail fuel systems from injector-killing contaminants. Replaces Cummins 4934879 and is approved for Cummins fuel filter housings FH126, FH21099, FH21100, and FH21103.
Specifications
| Manufacturer | Fleetguard (Cummins Filtration) |
|---|---|
| Part Number | FS1065 |
| Part Type | Fuel/Water Separator (Spin-On) |
| Engine Compatibility | Cummins ISC 8.3L, ISL 9.0L, ISB 6.7L, L9; Paccar PX-8, PX-9 |
| Filter Media | StrataPore synthetic |
| Micron Rating | 10 micron (SAE J1985) |
| Filtration Efficiency | 98.7% (SAE J1985) |
| Water Separation | 95% free and emulsified |
| Overall Height | 9.79 in (248.7 mm) |
| Outer Diameter | 3.69 in (93.7 mm) |
| Thread Size | 1-14 UNS-2B |
| Standpipe | Yes |
Cross References
This part replaces or is equivalent to the following part numbers:
- Cummins: 4934879, 3959505S
- Baldwin: BF1378-SPS
- Donaldson: P551103
- WIX: 33965
- NAPA: 3965
- Luberfiner: LFF1065
- Fram: PS10716
- Hastings: FF1172SPS
Applications
This fuel/water separator fits the following engines:
- Cummins ISC 8.3L (2003-2010)
- Cummins ISL 9.0L (2003-2010)
- Cummins ISB 6.7L (2007-2012)
- Cummins L9 (2017-present)
- Paccar PX-8 / PX-9 (2010-present)
Representative vehicles using these engines:
- Freightliner M2 106, M2 112, Business Class (2003-present)
- Kenworth T370, T440, T470 (2008-present)
- Peterbilt 337, 348, 365, 367 (2008-present)
- International 4300, 4400, DuraStar (2003-2015)
- Thomas Built, Blue Bird, IC school buses with Cummins ISC/ISL/ISB
Verify your engine serial number, fuel filter housing, and thread size before ordering to confirm fitment.









