Some 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 wall and the inner surface of the cylinder block next to the cylinder wall. The addition of a corrosion inhibitor (a chemical that gives a reduction of pitting) can keep this type of damage to a minimum.
The “spin-on” coolant conditioner element, similar to the fuel filter and oil filter elements, fastens to a base that is mounted on the front of the engine. Coolant flows from the water pump through the base and element back to the block. There is a constant flow of coolant through the element when valves are in the OPEN position.
The element has a specific amount of inhibitor for acceptable cooling system protection. As coolant flows through the element, the corrosion inhibitor, which is a dry material, dissolves (goes into solution) and mixes to the correct concentration. Two basic types of elements are used for the cooling system, and they are called the “PRECHARGE” and the “MAINTENANCE” elements. Each type of element has a specific use and must be used correctly to get the necessary concentration for cooling system protection. The elements also contain a filter and should be left in the system so coolant flows through it after the conditioner material is dissolved.
The “PRECHARGE” element has more than the normal amount of inhibitor, and is used when a system is first filled with new coolant. This element has to add enough inhibitor to bring the complete cooling system up to the correct concentration.
The “MAINTENANCE” elements have a normal amount of inhibitor and are installed at the first change interval and provide enough inhibitor to keep the corrosion protection at an acceptable level. After the first change period, only “MAINTENANCE” elements are installed at specified intervals to give protection to the cooling system.