ADAPTER 3G7173 - Caterpillar

Extended change periods, for the elements shown in the above chart, can result in the loss of adequate cooling system protection.
The precharge elements will give the correct charge of 1.5 to 3 ounces per gallon in the cooling system when it is filled. The maintenance elements, and the correct change periods, will keep the corrosion inhibitor in the cooling system between a maximum charge of 3.4 ounces per gallon and a minimum charge of .8 ounces per gallon for a 2,000 hour maintenance period. After 2,000 hours of operation, the cooling system must be drained and filled again. This will prevent salt deposits in the cooling system caused by the evaporation (water goes to vapor) and addition of water to the system.
Hot coolant will cause burns. Change elements only when the coolant is bold. Before the elements are removed, close the inlet and outlet valves to prevent the loss of coolant.
Before an element is installed, make sure it is the correct element for that application. The elements have the part number on them for easy identification. If paint has been put on the elements, identification can be made by the length of the element. See the chart that follows:
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 the 9N3717 Maintenance Element when Dowtherm 209 and water are used in the cooling system.
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.
Adaptable To: The attachment groups are not available for parts service as groups, but the separate parts can be ordered. The parts will be listed under their group numbers in the Parts Book Microfiche. The parts will also be given in the parts books at the next revision. The groups are adaptable to the 3406, 3408 and 3412 engines as shown in the chart that follows: The elements can be used on other engines if a mounting bracket is made. A 9N3668 Base Assembly and two 9N3666 Valve Assemblies will be needed. The chart that follows can be used as a selection guide for elements based on cooling system capacity.
INSTALLATION: For installation of the attachment group use SPECIAL INSTRUCTION, Form SEHS7222, Installation of Coolant Conditioner Group On Truck Engines, for a reference.