Cummins/Onan — Priming the Fuel System - Low Pressure
Maintenance
From a Cummins/Onan operator's manual covering: C121, DL4, DL6, DL6T, ES1178, FB2, L423, LS1629, TI0. Check it applies to your exact model before use.
Applies to: Cummins/Onan DL4, Cummins/Onan DL6, Cummins/Onan DL6T, Cummins/Onan L423D engine, Cummins/Onan L634D engine, Cummins/Onan L634T engine
Procedure
- Check fuel level and open shutoff valve
- Loosen fuel filter to injection pump line at injection pump fuel inlet fitting
- Actuate priming lever on transfer pump until fuel flows from fitting
- Tighten fuel line at injection pump inlet
Full service-parts list: Cummins/Onan DL6 →
Source: Cummins/Onan operator'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.