Cummins/Onan — Refilling Cooling System
Maintenance
From a Cummins/Onan operator's manual — check it applies to your exact model before use.
Applies to: Cummins/Onan HDKC
Procedure
- Install the coolant drain plug using pipe thread sealant.
- Tighten it just enough to prevent leaks when the generator set is running and has warmed up.
- Pull the hose connected to the pressure cap assembly out as far and high as it will go, and fill the system with coolant.
- When the coolant level reaches the fill opening, start and operate the generator set for a few minutes and shut it down.
- Add more coolant if necessary.
- Secure the pressure cap.
Specs & values
- Cooling System Capacity 6.2 liters (6.6 qt)
Full service-parts list: Cummins/Onan HDKC →
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.