F141275 Force FITTING, THERMOSTAT

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Remember that temperature and pressure work together. When a diagnosis is made of a cooling system problem, both temperature and pressure must be checked. Cooling system pressure will have an effect on the cooling system temperature. For an example, refer to Illustration 1. This will show the effect of pressure on the boiling point (steam) of water. This will also show the effect of height above sea level on the boiling point (steam) of water.
Caterpillar recommends that the coolant mixture contain a minimum of 30 percent 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 could 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 percent concentration of cooling system conditioner at all times.Use Caterpillar liquid cooling system conditioner to treat the coolant mixture.
Note: Do not use more than the recommended amount of 6 percent of supplemental coolant additive together with concentrations of antifreeze that are greater than 60 percent. Deposits can form in the cooling system. The deposits can result in radiator tube blockage, overheating, and/or damage to the water pump seal.
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Test location of water temperature (1) PlugRemove plug (1) in order to check water temperature. Refer to Test Tools For Cooling System for the tools and procedures for testing water temperature.
Making contact with a running engine can cause burns from hot parts and can cause injury from rotating parts.When working on an engine that is running, avoid contact with hot parts and rotating parts.
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4C-6500 Digital Thermometer The 4C-6500 Digital Thermometer is used to test for any overheating conditions or for any cooling problems. This group can be used to check temperatures in several different parts of the cooling system. Refer to the testing procedure in Operating Manual, NEHS0554.
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285-0910 Multi-Tool Gp The 285-0910 Multi-Tool Gp is used to check the air flow through the radiator core. The operating instructions are included in the group.
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9U-7400 Multitach Tool Group The 9U-7400 Multitach Tool Group is used to check the fan speed. The testing procedure is in Operating Instructions, NEHS0605.Check the coolant solution frequently in cold weather for the concentration of glycol with a 245-5829 Coolant/Battery Tester Gp . Check the coolant solution in order to ensure that the protection of the cooling system is adequate. Both testers are used for checking the point of freezing of the coolant. The tester gives an immediate reading and the tester gives accurate readings. The tester can be used for diesel engine antifreeze/coolants that contain ethylene or propylene glycol.Make Proper Additions To Antifreeze
Table 2
Antifreeze Concentration    
Temperature of Protection     Concentration    
Protection to -15 °C (5 °F)     30 % antifreeze and 70 % water    
Protection to
-23 °C (-10 °F)     40 % antifreeze and 60 % water    
Protection to
-37 °C (-34 °F)     50 % antifreeze and 50 % water    
Protection to
-51 °C (-60 °F)     60 % antifreeze and 40 % water    Do not add pure antifreeze fo