CABLE AS 1435968 - Caterpillar

3406 and 3408 Truck EnginesSome conditions of operation have been found to cause pitting (small holes in the metal surface) from corrosion or cavitation erosion (wear caused by air bubbles in the coolant) on the outer surface of the cylinder liners and the inner surface of the cylinder block next to the liners on 3406 and 3408 Truck Engines. Correct maintenance of the cooling system can stop this type of damage.
Many new 3406 and 3408 Truck Engines are equipped with an attachment group for the cooling system. This group automatically adds a corrosion inhibitor to the cooling system coolant. The elements used in the group have a specific amount of corrosion inhibitor. As water or coolant flows through the element, the corrosion inhibitor, which is a dry material, dissolves (goes into a solution) and mixes with the water or coolant to the correct amount of concentration.
Truck engines equipped with this attachment use an element with a larger than normal amount of inhibitor (precharge) at time of delivery. At the first oil change interval, the precharge element is removed and an element with a normal amount of inhibitor (maintenance) is then installed to keep the corrosion and pitting protection at an acceptable level. At all later change periods, only maintenance elements are installed to keep the cooling system protection needed.
When a cooling system is drained and filled with new coolant or water, a precharge element must be installed to give acceptable protection.Use the chart that follows to find the correct precharge and maintenance elements:
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.