CONTROL GP-TRANSMISSION HYD 2655278 - Caterpillar

When a precharge element is installed, make sure the label on the element reads "PRECHARGE".The service life of a coolant conditioner element is based upon a 10,000-12,000 mile (16,100-19,300 km) change interval and an expected coolant life of 100,000 miles (161,000 km) or one year.
Any extension of the element change period beyond the 10,000-12,000 mile recommendation can result in the loss of adequate cooling system protection.
If water must be added to the cooling system on a daily basis, either the cooling system has a leak or too much water is added (overfilling). Both of these procedures dilute (make weaker) the concentration of inhibitor.
An optional method to give protection to the cooling system is to use Dowtherm 209 antifreeze. No precharge element is needed when Dowtherm 209 is used. But because Dowtherm 209 does lose its ability to give protection, a maintenance element needs to be installed at every other oil change period. Use a 9N3717 Maintenance Element when Dowtherm 209 and water are used in the cooling system.
Follow the 100,000 mile or yearly drain interval recommendations shown in the Lubrication and Maintenance Guides for 3406 and 3408 Truck Engines. This permits debris to be flushed from the cooling system and new coolant or water and new corrosion inhibitor to be added.