41721 Mercruiser WASHER, For Use Without Trim Senders

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 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.Dowtherm 209 full-fill coolant will lower the water pump cavitation temperature and coolant boiling point. These lowered temperatures will cause overheating at a lower ambient temperature than an ethylene glycol and water mix. If Dowtherm is used, follow the instructions provided and use only the inhibitor package recommended by the supplier.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 -28°C (-20°F) 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 every 6000 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 20 L (5 U.S. gallons) 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 "Coolant and Your Engine" SEBD0970, for more information.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 to reduce the potential and severity of chemical insolubility. Using water that meets the minimum acceptable water requirement may not prevent drop-out of these chemical compounds totally, but should minimize the rate to acceptable levels.To determine water characteristics, contact local water department, agricultural agent or an independent laboratory to perform the testing service. Two companies are listed below, however there are others who are qualified to provide this service.L.O.C.C. Corp.
905 Bayshore Drive
Coos Bay, OR 97420
Ph. (503) 267-4904
NALCO Chemical Co.
Naperville Technical Center
One Nalco Center
Naperville, IL 60566
Attn: Sample Receiving
Ph. (312) 961-9500
Antifreeze
Caterpillar recommends that the coolant mix contain a minimum of 30% Caterpillar Antifreeze, or equivalent and acceptable water to maintain an adequate water pump cavitation temperature for efficient water pump performance.Premix coolant solution to provide protection to the lowest expected outside (ambient) temperature. Pure undiluted antifreeze will freeze at -23°C (-10°F).Only use a greater concentration (above 30%) of Caterpillar Antifreeze as needed for anticipated outside (ambient) temperatures. Do not exceed a coolant mixture of 60% antifreeze to water since a concentration above 60% antifreeze will reduce the engine's freeze protection and increase the possibility of deposit formation in the cooling system.
Use Caterpillar Antifreeze or ASTM D4985-89 (GM Specification 6038-M) Antifreeze. Caterpillar Antifreeze is available through your Caterpillar dealer in quantities that follow. Most commercial antifreezes are formulated for gasoline engine applications and will, therefore, have high silicate content. Caterpillar Antifreeze is formulated with a low silicate content and the proper coolant additives for heavy duty diesel engines.ASTM D4985-89 (GM Specification 6038-M) is a low silicate antifreeze, but supplemental coolant additive must be added.The major advantages of Caterpillar Antifreeze are:* Significantly reduces water pump seal leakage problems caused by excessive concentration of chemical additives.* There is no need to add supplemental coolant additive on initial fill which must be done with current commercially available antifreezes.* High silicate antifreezes used with a supplemental coolant additive can cause a build-up of solids over a period of time which can cause plugging, loss of heat transfer, and water pump seal damage. Make proper antifreeze additions.Adding pure antifreeze as a makeup solution for cooling system top-up is an unacceptable practice. It increases the concentration of antifreeze in the cooling system which increases the concentration of dissolved solids and undissolved chemical inhibitors in the cooling system. Add antifreeze mixed with water to the same freeze protection as your cooling system.Use the chart below to assist in determining the concentration of Caterpillar Antifreeze to use.
5P3514 Coolant Tester (°C) or 5P0957 Coolant Tester (°F)Both are available at your Caterpillar dealer.Check the coolant solution frequently in cold weather for glycol concentration with the 5P0957 or 5P3514 Coolant Tester to ensure adequate protection. Both testers are identical except temperature scale. They give immediate, accurate readings and can be used for antifreeze/coolants that contain ethylene or propylene glycol.If propylene glycol based antifreeze is used, DO NOT allow concentration greater than a 50/50 antifreeze to water mixture. The measurement of freeze protection must be made with a refractive-type tester (Cat 5P0957 or 5P3514) rather than a hydrometer-type, which can be used to test ethylene glycol based antifreeze.Supplemental Coolant Additive
Supplemental coolant additive is necessary to