42144A 2 Mercury BEARING CARRIER

Fresh Water Cooling System
Coolants: Water used in the cooling system should be as free as possible from scale forming minerals, not softened. If it is impossible to obtain soft water it is advisable to treat the available water with Caterpillar Rust Inhibitor. The use of this rust inhibitor in the cooling system will prevent the formation of rust. It will also retard, and in some cases completely eliminate mineral deposits within the engine. Most commercial anti-freeze solutions contain rust inhibitors. Your Caterpillar dealer stocks Caterpillar Rust Inhibitor in convenient one quart cans. Directions for its use are printed on each can.When the temperature is below freezing sufficient anti-freeze should be used in the fresh water cooling system to prevent freezing. Various anti-freeze mixtures such as ethylene glycol (Prestone, G.M., Permaguard, Zerex, etc.) denatured ethyl alcohol, methanol (synthetic wood or methyl alcohol) and glycerine are all suitable for use. Alcohol can be used successfully but, because it readily evaporates at the normal operating temperature of the diesel engine the solution should be tested frequently -even daily-and kept up to correct strength. This loss by evaporation is objectionable but the temperature regulator should not be removed. Doing so might make the solution run cooler and save the alcohol, but is not desirable for good performance. It is essential, therefore, that the coolant be tested frequently to assure adequate protection. Draining: The cooling system should be drained every 1000 service hours to remove any accumulation of dirt or sediment. This should be done at the end of a run when the foreign material is in suspension and will drain with the water. The fresh water cooling system can be drained by removing the plug (1) at the right side of the diesel engine cylinder block, and the plug (2) at the bottom of the fresh water line from the pump to the engine oil heat exchanger. The heat exchanger is drained by removing the fresh water drain plugs (3) from the bottom of the heat exchanger body.
DRAINING FRESH WATER SYSTEM
1-Cylinder block drain plug. 2-Fresh water line drain plug. 3-Heat exchanger fresh water drain plugs. Cleaning the Cooling System: Wash the cooling system periodically. To wash, stop the engine when it is at normal operating temperature and drain as quickly as possible. Flush thoroughly, then fill with a solution of one pound of Oxalic Acid or Sodium Bisulfite per five gallons of water. Run the engine at operating temperature one-half to one hour, then drain and flush until water is clear. Fill with a solution of one-half pound of Sal Soda per ten gallons of water and run the engine ten minutes. Drain, flush and fill with water, adding corrosion inhibitor or the desired amount of anti-freeze. Filling: Fill the fresh water cooling system by pouring the coolant into the surge tank filler opening.During operation, the coolant will expand due to heat of the engine. Approximately one gallon of additional capacity in the expansion tank is required for each 23 gallons of coolant in the system. For this reason, the expansion tank should not be completely filled when the engine and coolant are cold, as the excess coolant will be wasted through the overflow pipe when it expands. Actual experience will determine the level of coolant required.Raw Water System
In certain waters heat exchangers will become less efficient due to marine growths and may also accumulate sediment. As such materials accumulate, the fresh water temperature indicator will show a gradual day-to-day increase in reading. Before this reading approaches the boiling point this accumulated material should be removed. Draining: The raw water cooling system should be drained when the boat is to be left in storage, at the end of a day's run in freezing weather, or when the heat exchanger is to be cleaned.1. Close the sea valve.2. Remove the plate (1) from the rear of the raw water pump.
RAW WATER PUMP
1-Drain plate. 2-Priming plug.3. Remove the plugs (3) from the bottom of each end bonnet of the heat exchanger.
HEAT EXCHANGER DRAINING
3-Drain plugs.Also, if there is a low point anywhere in the line, remove the plug or disconnect the pipe.To prime the raw water pump on earlier engines remove the priming plug (2) on top of the pump priming chamber and fill with water. Replace the plug and immediately start the engine. Later engines have positive displacement pumps and do not require priming. Cleaning The Heat Exchanger: The heat exchanger should be cleaned when the water temperature is continuously 195° to 205° or more during operation.Close the sea valve and drain the exchanger of raw water by removing the drain plugs (2). Remove the end bonnets (1) from each end of the exchanger. A rod not larger than 9/32 inch (7.11 mm.) can be used to push through the tubes of the core to remove accumulations. Reinstall the end bonnets and open the sea valve. When the engine is started, any accumulations which were loosened in the tubes will be flushed out of the core.
CLEANING HEAT EXCHANGER
1-End bonnets. 2-Raw water drain plugs. Zinc Plugs: Zinc plugs are installed in the raw water circuit for the purpose of localizing any electrolytic action which may be set up. For easy identification, all zinc plugs are painted red. Two zinc plugs are located in the heat exchanger, and two zinc plugs are located in the ends of the marine gear oil cooler and two in the raw water aftercooler. They should be inspected every 25 service hours and replaced if deteriorated. To inspect them close the sea valve, drain the exchanger of raw water and remove the plugs. In draining the water the tubes of the core will be drained because the raw water circulates through the inside of the tubes. When inspecting the zinc plugs do not be deceived by their outside appearance but tap them lightly with a small hammer. If they crack or crumble new zinc elements should be installed. If they are not deteriorated and merely appear to be corroded they may