1980/04/09 Caterpillar

All Engines

NOTE: This information is to be used in place of all earlier information about Dowtherm 209 Anti-freeze. Make a reference note in your copies of "Know Your Cooling System," Form SEBD0518, and the article "Attachment Groups Put Corrosion Inhibitor Directly Into Cooling System" on Page 6 of the June 14, 1978 Engine News to see this article.

Dowtherm 209 has been changed from an anti-freeze concentrate (a solution to be mixed with water) to an anti-freeze coolant mixture known as Dowtherm 209 Full-Fill. This coolant is a mixture of 53% methoxy propanol and 47% deionized water plus corrosion inhibitors, and gives anti-freeze protection to a temperature of -34°C (-30°F). The corrosion inhibitor package is fully saturated (at a maximum solution) in the 53/47 ratio coolant mixture, so the addition of any product except Dowtherm 209 Full-Fill will decrease the amount of inhibitor available for system protection. For this reason, Dowtherm 209 Full-Fill can not be used with any of the corrosion inhibitors which are acceptable for Caterpillar Tractor Co. recommendations. Also, no corrosion inhibitor package is available from the Dow Chemical Company for addition to the coolant after a period of use.

Since no corrosion inhibitor can be added to cooling systems filled with Dowtherm 209 Full-Fill coolant, the recommendation is to drain, flush and fill the system with new coolant at intervals of 2000 SMU or one year, whichever comes first. Be sure your customers who use Dowtherm 209 Full-Fill coolant understand this recommendation. Dowtherm 209 Full-Fill will not be available from Caterpillar Tractor Co. as original factory coolant.

Dow Chemical Company recommendations for use of Dowtherm 209 Full-Fill are as follows:

... Thoroughly drain, clean and flush the complete system before Dowtherm 209 Full-Fill is installed. Be sure every part of the system is completely drained.

... Do not use Dowtherm 209 Full-Fill in systems that have dry chemical, chemically treated sissle cloth, or paper coolant filters.

... Use only Dowtherm 209 Full-Fill when coolant must be added to the system.

... Do not add water to the system.

... Do not add "Cootherm Cooling System Conditioner" to the system.

... Do not use in gasoline spark ignition engines.

... Do not use in units which are in a closed area that prevents a good flow and rapid change of air.

... Do not use in any vehicle (like buses, etc.) used for public transportation (the transport of persons).

... Do not mix with any other anti-freeze coolant.