Description
The Paccar K37-1004 is a genuine OEM fuel/water separator cartridge element for Paccar MX-13 and Cummins ISX15 engines, capturing 99% of particles down to 10 microns while separating water from diesel fuel. Designed for 2010-emission compliant engines, it fits Peterbilt and Kenworth trucks running EPA 2010 and EPA 2004 certified powerplants. The Fleetguard equivalent is FS36401, an upgraded replacement for the discontinued FS20075.
Signs You Need a New Fuel Filter
- Reduced engine power or sluggish acceleration
- Hard starting or extended cranking
- Engine surging, hesitation, or stalling under load
- Check engine light with fuel system fault codes
- Water-in-fuel warning indicator illuminated
Specifications
| Manufacturer | PACCAR |
|---|---|
| Part Number | K37-1004 |
| Part Type | Fuel/Water Separator Cartridge Element |
| Micron Rating | 10 microns @ 99% efficiency |
| Overall Height | 7.62 in (193.6 mm) |
| Outside Diameter | 4.16 in (105.7 mm) |
| Engine Compatibility | Paccar MX-13, Cummins ISX15, Cummins X12 |
| Emission Standards | EPA 2010, EPA 2004 |
Cross References
This filter replaces or is equivalent to the following part numbers:
- PACCAR: K37-1004, K371004
- Fleetguard: FS36401 (replaces FS20075)
- Baldwin: PF9928
- Donaldson: P557004
- WIX: WF10249
- NAPA: 600249
- Luber-finer: L5094F
- Hastings: FF1286
Applications
This fuel filter fits the following engines:
- Paccar MX-13 12.9L (2010+, EPA 2010 / EPA 2004)
- Cummins ISX15 14.9L (2010-2016)
- Cummins X12 11.8L
Representative vehicles using these engines:
- Kenworth T660 (2010-2016), T680 (2013-2018), T700 (2010-2014), T800 (2010-2018)
- Peterbilt 365 (2011-2018), 384 (2010-2016), 386 (2010-2016), 388 (2010-2015), 389 (2010-2018), 587 (2010-2018)
Verify your engine serial number and fuel system configuration before ordering. Later model year trucks (2017+) may use updated filter part numbers.









