Cummins/Onan — Fill Cooling System (Spec. A)
Maintenance · Jacket water and LTA cooling systems
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan DQKB, Cummins/Onan DQKC, Cummins/Onan QSK60 engine
Before you start
- Failure to properly replace coolant caps can result in hot pressurized coolant escaping, causing severe personal injury and engine damage.
Procedure
- Open the petcock at the top of each of the four turbochargers.
- Open the jacket water (front) radiator cap; fill with antifreeze, water, and SCA.
- Close each petcock when coolant begins to flow and continue filling.
- Observe coolant level through the sight glass; should be mid-glass with a cool engine.
- Replace the radiator cap securely.
- Remove the LTA (rear) radiator cap; fill with antifreeze, water, and SCA.
- Observe LTA coolant level through the expansion tank sight glass; mid-glass when cool.
- Replace LTA radiator cap securely.
Specs & values
- Jacket water radiator 100 gallons (379 liters)
- LTA radiator 34 gallons (129 liters)
Full service-parts list: Cummins/Onan DQKB →, Cummins/Onan DQKC →
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.