Cleaning the Heavy-Duty Cooling System

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7. Low Silicate Coolant

Any coolant that has low silicate content is acceptable if the coolant meets the following requirements: • TMC RP329 • TMC RP330 • ASTM D4985 For proper corrosion protection, Caterpillar recommends the use of a coolant mixture that is at least 30 percent glycol and 70 percent water and supplemental coolant additive. In order to prevent water pump cavitation, all Caterpillar engines that have an air-to-air aftercooler require a minimum glycol concentration of 30 percent. Although the minimum acceptable glycol concentration is 30 percent, Caterpillar recommends the use of a coolant mixture that is 50 percent glycol and 50 percent water and supplemental coolant additive. This coolant mixture helps to provide optimum engine performance. When you initially fill the cooling system with Caterpillar Diesel Engine AntifreezeCoolant, it is not necessary to add supplemental coolant additive. Caterpillar Diesel Engine AntifreezeCoolant already contains supplemental coolant additive. When you initially fill the cooling system with a commercial coolant that meets the requirements of ASTM D4985, add a supplemental coolant additive. The supplemental coolant additive in Caterpillar Diesel Engine AntifreezeCoolant and in commercial coolants must be replenished at regular service intervals. When you initially fill the cooling system with a commercial coolant that meets the requirements ofASTM D4985, refer to the table below for the proper quantity of liquid supplemental coolant additive.

8. Supplemental Coolant Additive SCA

Caterpillar SCA effectively prevents corrosion on all metals and Caterpillar SCA effectively prevents the formation of mineral deposits. Caterpillar SCA also prevents cavitation of the liner and Caterpillar SCA eliminates foaming of the coolant. Test the SCA concentration or submit a coolant sample to your Caterpillar dealer at every oil change. After every 250 service hours, liquid SCA or a SCA maintenance element may be needed. SCA additions are based on the results of coolant analysis. Your Caterpillar dealer has test kits that will evaluate the concentration of additives in Caterpillar DEAC. The following table indicates the amount of Caterpillar SCA that is needed at the initial fill to treat commercial heavy-duty coolantantifreezes. The table also shows the addition of an SCA for either liquid SCA or for the maintenance elements of a SCA. These additions are for commercial heavy-duty coolantantifreezes and for Caterpillar DEAC. 157

9. Contamination of the ELC Cooling System

NOTICE Mixing ELC with other products reduces the effectiveness of the coolant and shortens coolant life. Use only Caterpillar products or commercial products that have passed the Caterpillar EC-1 specification for pre-mixed or concentrate coolants. Use only Caterpillar Extender with Caterpillar ELC. Failure to follow these recommendatioins can result in short- ened cooling system component life. In cooling systems that use Caterpillar ELC, do not add Diesel Engine AntifreezeCoolant DEAC as a makeup coolant. Contamination of ELC by DEAC will defeat the advantages of ELC. If the ELC in the cooling system becomes contaminated by more than 10 percent of the total system capacity of DEAC or if SCA is added, perform one of the following operations: • Drain the cooling system into a suitable container. Dispose of the coolant according to local regulations. Flush the system with clean water. Fill the system with the Caterpillar ELC. • Maintain the system as a conventional Diesel Engine AntifreezeCoolant DEAC. Treat the system with an SCA. Change the coolant at the interval that is recommended for the conventional Diesel Engine AntifreezeCoolant DEAC. COOLING SYSTEM SPECIFICATIONS

1. General Coolant Information

Many engine failures are related to the cooling system. Cooling system failures include the following problems: overheating, leakage of the water pump, plugged radiators and cylinder liner pitting. These failures could be avoided with proper cooling system maintenance. Maintenance of the engine coolant is important to the engine life and to the performance. This maintenance is as important as fuel quality. This maintenance is as important as the maintenance of the system for lubricating oil. Coolant is normally composed of three elements: 1. Water 2. Additives 3. Glycol