Cummins/Onan — Lubrication System Fill and Prime
Maintenance · engine lubrication system
From a Cummins/Onan service manual covering: 400 DFEB, 450 DFEC, 500 DFFB. Check it applies to your exact model before use.
Applies to: Cummins/Onan 500 DFFB, Cummins/Onan KTA19-G2 engine, Cummins/Onan KTA19-G3 engine, Cummins/Onan KTTA19-G2 engine
Procedure
- Remove oil inlet line from turbocharger housing; fill bearing housing with clean engine lubricating oil; replace line and secure.
- Fill crankcase to L (low) mark on dipstick.
- Connect a hand or motor driven priming pump with pressure gauge from clean oil source to the plug boss in the filter housing.
- Prime until a 30 psi (207 kPa) pressure is obtained.
- Disconnect wire from fuel solenoid valve.
- On the engine control panel, depress the RUN switch to crank the engine, maintaining 15 psi (103 kPa) oil priming pressure for 15 seconds at the filter head priming port.
- Stop engine cranking, remove external priming equipment, reinstall plug in filter housing and torque to 15 to 20 ft lb (20 to 27 N·m).
- Reconnect wire to fuel solenoid valve.
- Complete oil fill to H (high) mark on dipstick.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 30 psi (207 kPa) priming pressure
- 15 psi (103 kPa) during cranking for 15 seconds
- 15 to 20 ft lb (20 to 27 N·m) filter housing plug torque
Full service-parts list: Cummins/Onan 500 DFFB →
Source: Cummins/Onan service 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.