TUBE AS 1986855 - Caterpillar

Coolant Information
Diesel engine operating temperatures have increased to improve engine efficiency. This means proper cooling system maintenance is especially important. Overheating, overcooling, pitting, cavitation erosion, cracked heads, piston seizures and plugged radiators are classic cooling system failures. In fact, coolant is as important as the quality of fuel and lubricating oil.
Caterpillar recommends that the coolant mixture contain a minimum of 30% Caterpillar Antifreeze, or equivalent. Liquid supplemental coolant additive must be added, when not using Caterpillar Antifreeze, which contains the proper additive. Never add coolant to an overheated engine, engine damage can result. Allow the engine to cool first.All water is corrosive at engine operating temperature. The cooling system should be protected with a 3% to 6% concentration of liquid supplemental coolant additive at all times, regardless of the concentration of antifreeze.Excessive supplemental coolant additive greater than the recommended 6%, together with concentrations of antifreeze greater than 60% can cause deposits to form and can result in radiator tube blockage, overheating, and/or water pump seal damage.DO NOT use Dowtherm 209 Full-Fill coolant.Do not use liquid supplemental coolant additive or elements or antifreeze with Dowtherm 209 Full-Fill coolant. Dowtherm 209 Full-Fill coolant is not compatible with other antifreeze and coolant mixtures.If the engine is to be stored in, or shipped to, an area with freezing temperatures, the cooling system must be protected to the lowest expected outside (ambient) temperature.The engine cooling system is normally protected to -20°F (-28°C) with Caterpillar Antifreeze, when shipped from the factory unless special requirements are defined.
Check the specific gravity of the antifreeze solution frequently in cold weather to ensure adequate freeze protection.Clean the cooling system if it is contaminated, if the engine overheats, or if foaming is observed in the radiator.Coolant should be drained, the system cleaned and new coolant added at PM Level 2 (every 3000 service hours or two years). When not using Caterpillar Antifreeze and supplemental coolant additive as recommended, the drain period must be shortened to 1500 service hours or one year.Filling at over 5 U.S. gal (20 L) per minute can cause air pockets in the cooling system.After draining and refilling the cooling system, operate the engine with the radiator cap removed until the coolant reaches normal operating temperature and the coolant level stabilizes. Add coolant as necessary to fill the system to the proper level.Never operate without a thermostat in the cooling system. Cooling system problems can arise without a thermostat.Refer to "Know Your Cooling System," form SEBD0518 and "Coolant and Your Engine" form SEBD0970, for more detailed specifications.Coolant Water
Hard water, or water with high levels of calcium and magnesium ions, encourages the formation of insoluble chemical compounds by combining with cooling system additives such as silicates and phosphates.The tendency of silicates and phosphates to precipitate out-of-solution increases with increasing water hardness. Hard water, or water with high levels of calcium and magnesium ions encourages the formation of insoluble chemicals, especially after a number of heating and cooling cycles.Caterpillar prefers the use of distilled water or deionized water