Cummins/Onan — Fuel filter change
Maintenance · Fuel system
From a Cummins/Onan owner's manual covering: CFP-015, CFP11E, CFP15E, CFP23E, CFP30E, CFP50, CFP59, CFP5E, CFP60E, CFP7E, CFP83, CFP83-F10…. Check it applies to your exact model before use.
Applies to: Cummins/Onan CFP23E, Cummins/Onan CFP83-F10, Cummins/Onan CFP83 engine
Before you start
- Do not open the fuel filter/water separator drain valve or dismantle the fuel lines on the high-pressure fuel system with the engine running.
- If the engine does not start after three attempts, check the fuel supply system.
Parts for this job
- FS1006 Fuel filter — Cummins/Onan CFP23E Amazon eBay $29.99 NAPA $90.16
- FS1251 Fuel filter — Cummins/Onan CFP83-F10 Amazon eBay $119.92 NAPA $23.51
Part numbers from the service-parts lists for Cummins/Onan CFP23E, Cummins/Onan CFP83-F10. Verify against your serial number before ordering; some links are affiliate links.
Procedure
- Shut off the engine.
- Close any fuel valves to prevent fuel from draining or siphoning.
- Clean the area around the fuel filter or fuel/water separator heads.
- Remove the spent filter canisters using a filter wrench.
- Clean the filter mounting head surfaces and ensure mating gasket surfaces are clean.
- Lubricate the gasket seals with clean SAE 15W-40 lubricating oil.
- Center the filter ring on the threaded mounting nipple; screw on until the gasket is snug, then tighten an additional 1/4 turn.
- Open the fuel supply valves.
- Press the CRANK BATT A or CRANK BATT B button to start the engine and allow fuel to flow.
- Depress the contactor switch for up to fifteen seconds or until the engine starts.
Tools required
- Filter wrench Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Tighten an additional 1/4 turn after gasket contact
Full service-parts list: Cummins/Onan CFP23E →, Cummins/Onan CFP83-F10 →
Source: Cummins/Onan owner's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.