
Fuel Filters
Part Number: R61709
Models: Cascadia, M2
Engines: DD13, DD15, DD16
Fits Detroit 03-40538-009 fuel processor housing
The R61709 is a cartridge-style fuel/water separator element engineered for Detroit Diesel DD13, DD15, and DD16 engines. It installs in the Detroit 03-40538-009 fuel processor housing used on Freightliner Cascadia, Western Star, and Freightliner M2 platforms — delivering the 5–10 micron particulate capture and water separation required to protect high-pressure common rail injectors. Key Features 5–10 micron filtration protects common rail injectors from abrasive wear Up to 98% free-water separation and 83% emulsified-water removal StrataPore-grade multi-layer media for high dirt-holding capacity Fits the Detroit 03-40538-009 fuel processor housing — drop-in replacement Integrated bypass valve maintains fuel flow under high restriction Supplied with fresh O-rings for a leak-free service Why It Matters Modern Detroit DD-series fuel systems combine extreme injection pressures with tight component tolerances. Water and fine debris cause rapid injector-tip erosion, poor spray geometry, misfires, and eventual derate conditions. Replacing the R61709 on schedule with a properly spec’d element keeps combustion clean, preserves emissions compliance, and avoids the cascade of damage that follows a compromised fuel system. Application & Fitment Freightliner Cascadia (2018+) and Cascadia 125 (2019+) Freightliner M2 and M2 106 Freightliner MT-45 and other medium-duty chassis Western Star trucks with Detroit DD-series power Any application using the Detroit 03-40538-009 fuel filter housing Cross-references to Fleetguard FS20176, Baldwin PF46235, Donaldson P552709, WIX WF10568, NAPA 600568, Luber-Finer L6048F, Carquest 96869, and Racor RAI R61709.
| Filter type | Fuel/water separator element |
|---|---|
| Engine family | Detroit Diesel DD13 (12.8L), DD15 (14.8L), DD16 (15.6L) |
| Housing compatibility | Detroit 03-40538-009 fuel processor |
| Overall height | 7 7/32 in (183.6 mm) |
| Outer diameter | 4 7/32 in (107.2 mm) |
| Micron rating | 5–10 microns |
| Bypass valve | Yes |
Compare the listed reference numbers with the part you are replacing before ordering.