Cummins/Onan — Cooling System - Cleaning System and Changing Antifreeze
Maintenance
From a Cummins/Onan owner's manual covering: K1800, K2000E, K38, K50, KT38, KTA 50 G3, KTA-50G3, KTTA50, KtA38, KtA50, KttA38. Check it applies to your exact model before use.
Applies to: Cummins/Onan K38, Cummins/Onan K50, Cummins/Onan KTA-50G3, Cummins/Onan KTA38, Cummins/Onan KTA50
Before you start
- Do not use caustic cleaners; aluminum components will be damaged.
- Wait until temperature is below 50 C [120 F] before removing the pressure cap.
Procedure
- Drain the cooling system; do not allow it to dry out.
- Add Fleetguard RESTORE or RESTORE PLUS (1 U.S. gallon per 38-57 liters capacity).
- Fill system with plain water.
- Operate engine at normal temperature (at least 85 C [185 F]) for 1 to 1.5 hours.
- Shut off and drain the system.
- Fill with clean water and operate at high idle 5 minutes above 85 C.
- Shut off and drain; repeat flush if water is still dirty.
- Refill with new heavy duty coolant and SCA.
Specs & values
Full service-parts list: Cummins/Onan K38 →, Cummins/Onan K50 →, Cummins/Onan KTA-50G3 →, Cummins/Onan KTA38 →, Cummins/Onan KTA50 →
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.