General Coolant Information Water Additives

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 Di unduh dari : Bukupaket.com 158

2. Water

NOTICE Never use water alone without Supplemental Coolant Additive SCAs or inhibited coolant. Water alone is corrosive at engine operating temperatures and does not provide adequate boil protection. Distilled water or deionized water is recommended for use in cooling systems. Do not use hard tap water or salt softened tap water in engine cooling systems. If distilled water or deionized water is not available, use water that meets the minimum requirements that are listed in the following table. Table Caterpillar Recommended Quality Limits Water Property grains3.8 L ppm1 US gal Chloride CI 2.4 40 maximum Sulfate 2 SO. 5.9 100 maximum Total Water Hardness 3 10 170 maximum Total Solids 4 20 340 maximum Total Solids 4 20 340 maximum Acidity 5 5.5 pH to 9.0 pH For a water analysis, consult one of the following organizations: 1. The Caterpillar Laboratory for an SOS Analysis 2. The LOCC Corporation 3. Local water department 4. Agricultural agent 5. Independent laboratory

3. Additives

Coolant additives help in the following ways: • Preventing rust from forming • Preventing scale and mineral deposits from forming Di unduh dari : Bukupaket.com 159 • Protecting metals from corroding • Preventing cavitation of the liner • Preventing coolant from foaming Many additives are depleted during engine operation and these additives need to be replaced. This can be done through the addition of Supplemental Coolant Additives SCA to Diesel Engine AntifreezeCoolant DEAC or by adding Extender to Extended Life Coolant ELC. Additives must be added at the proper concentration. Overconcentration of additives can cause the inhibitors to drop out-of-solution. This can cause a gel compound to form in the radiator. An overconcentration of additives can produce deposits on water pump seals that can cause water pump seal leakage. A low concentration of additives can produce the following problems: 1. Pitting 2. Cavitation erosion 3. Rust 4. Scale 5. Foaming

4. Glycol