The functions of the cooling system are to:

• absorb heat from the engine components,
• circulate the coolant in the engine,
• dissipate the heat through the radiator, and
• control coolant temperature by the thermostat.

The coolant must be made up of the correct proportions of water, antifreeze, and supplemental coolant additives (SCA) to properly perform these functions.

The accompanying chart illustrates the coolant flow through the engine. For more detail, refer to the coolant flow diagram.

Conventionally cooled engines with automatic transmissions typically use oil-to-water transmission torque converter coolers plumbed between the radiator and the engine water pump.

A torque converter cooling system with a remote bypass allows the torque converter to receive coolant flow when the thermostat is closed (engine cold).

The following publications, available through a Cummins® Authorized Repair Location, provide cooling system installation recommendations and specifications approved by Cummins Inc.:

• Data Sheets for specific engine models.
• Operation of Diesel Engines in Cold Climates, Bulletin No. 3379009.
• Heavy Duty Coolant/SCA Maintenance Requirements, Bulletin No. 3387910.