Make sure air is vented during the fill process:
• Some thermostats have check balls that allow air to vent through the thermostat when the thermostat is closed.
• An air vent port connection, which connects to the top tank/coolant recovery tank of the cooling system, is located next to the water outlet.
The system has a maximum designed fill rate of 19 liters [5 gal] per minute.
NOTE: Some applications may be equipped with a manual bleed valve which is to be opened to make sure
of a proper fill. The upper radiator pipe is a common location for bleed valves. The illustration is for reference only.
If applicable, open the manual bleed valve before filling the cooling system.
Once properly filled, make sure to close the manual bleed valve.
Refer to Cummins® Coolant Requirements and Maintenance, Bulletin 3666132, for engine coolant specifications.
Remove the cooling system fill cap.
Fill the cooling system to the capacity or level stated in the OEM service manual, using a mixture of 50 percent water
and 50 percent ethylene glycol or propylene glycol antifreeze.
