Cummins/Onan 12.5 RDJC / 15.0 RDJC — Oil Change
Maintenance · Crankcase
For the Cummins/Onan 12.5 RDJC / 15.0 RDJC, from the Cummins/Onan operator's manual.
Applies to: Cummins/Onan 12.5 RDJC, Cummins/Onan 15.0 RDJC, Cummins/Onan RDJC
Before you start
- Hot crankcase oil can cause burns if spilled or splashed on skin; keep fingers and hands clear when removing the oil drain plug and wear protective clothing
Parts for this job
- 122-0185 Oil filter Amazon Amazon eBay $19.55 eBay NAPA $12.88
Part numbers from the service-parts list for Cummins/Onan RDJC. Verify against your serial number before ordering; some links are affiliate links.
Procedure
- Stop the engine and drain the crankcase oil while the engine is still hot.
- Place a pan under the drain outlet and remove the oil drain plug or open the oil drain valve.
- After the oil is completely drained, replace the drain plug or close the drain valve.
- Replace oil filter if necessary before adding oil.
- Refill with oil of the correct API designation and SAE viscosity grade for the temperature conditions.
Tools required
- Drain pan Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Crankcase capacity 6.5 U.S. quarts (6.0 l)
- Check oil level after every 8 hours of operation
Full service-parts list: Cummins/Onan RDJC →
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.