Cummins/Onan — Coolant system preparation
Maintenance · Cooling system
From a Cummins/Onan owner's manual covering: CFP-015, CFP11E, CFP15E, CFP23E, CFP30E, CFP50, CFP59, CFP5E, CFP60E, CFP7E, CFP83, CFP83-F10…. Check it applies to your exact model before use.
Applies to: Cummins/Onan CFP23E, Cummins/Onan CFP83-F10, Cummins/Onan CFP83 engine
Before you start
- Do not remove the pressure/fill cap from a hot engine. Wait until coolant temperature is below 50 C (122 F).
Procedure
- Inspect the engine coolant hoses and hose clamps for proper installation and water tightness.
- Ensure the engine coolant heater maintains coolant temperature of 49 C (120 F) or above.
- Ensure coolant is present in the coolant heater before plugging into a dedicated circuit.
- Inspect the heat exchanger weekly for external damage and contamination.
- Add coolant if necessary: with sight gauge, keep level visible at center; without, fill to bottom of fill neck.
- Re-install the pressure/fill cap.
Tools required
- Refractometer Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Engine coolant heater maintains 49 C (120 F) or above
- 50% ethylene glycol antifreeze and 50% water
Full service-parts list: Cummins/Onan CFP23E →, Cummins/Onan CFP83-F10 →
Source: Cummins/Onan owner'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.