MAINTENANCE The viscosity of the fuel must be kept above 1.3 cSt to provide adequate fuel system lubrication. Optionally, the equivalent grades of recognized Federal Government specifications may be used; the latest revisions of VV-F-800a. 20.6 COOLANT SPECIFICATIONS 20.6.1 GENERAL Selection and maintenance of the engine coolant is important to long engine life. The following information provides recommendations for selecting the engine coolant and maintaining the supplemental coolant additives (SCA). Heavy duty diesel engines require a balanced coolant mixture of water, antifreeze, and supplemental coolant additives.
Supplemental coolant additive recommendations are included in the section entitled 20.6.4 SUPPLEMENTAL COOLANT ADDITIVES on page 3-14. The coolant mixture must be drained and replaced at the specified service interval shown in 23 MAINTENANCE SCHEDULE CHART on page 3-25 , or every two years of operation, whichever comes first. 20.6.2 WATER Use water which has a low mineral content. Water used in conjunction with antifreeze, coolant filters and inhibited water must meet the following standards: Total Hardness - Not to exceed 170 parts per million (10 grains/gallon maximum) to prevent scale deposits.
Water containing dissolved magnesium and calcium (the usual reason for water hardness) above the specified amount will cause scale deposits to develop in the engine. Chlorides - Not to exceed 40 parts per million (2.5 grains/gallon maximum) to prevent corrosion. Sulfites - Not to exceed 100 parts per million (5.8 grains/gallon maximum) to prevent corrosion. Dissolved Solids - Not to exceed 340 parts per million (20 grains/gallon maximum) to minimize sludge deposits, scale deposits, corrosion or a combination of these. If any of the above requirements cannot be met, use distilled, de-ionized, or de-mineralized water.
To determine if local water supplies meet these standards, water samples can be tested by water treatment laboratories. Softened water that is prepared using common salt (sodium chloride) contains excessive amounts of chlorides and should not be used. NOTICE: Never use water alone in the cooling system because rust, scale deposits and corrosion will occur. 20.6.3 ANTIFREEZE In climates where the temperature is above -34 Antifreeze is essential in any climate . It broadens the operating temperature range by lowering the coolant freezing point and by raising its boiling point. Do not use more than 50 percent antifreeze in the mixture unless additional freeze protection is required.
Never use more than 68 percent antifreeze under any condition. An antifreeze concentration greater than 68percent will adversely affect freeze protection and heat transfer rates. Antifreeze concentrations between 68 and 100percent actually have a higher freezing point than a 68percent antifreeze concentration and should not be used due to reduced heat transfer rates. Ethylene glycol, low silicate antifreeze is recommended. The antifreeze should contain no more than 0.1percent anhydrous alkali metasilicate. Low silicate antifreeze is recommended to avoid the formation of silica-gel (hydro-gel).
This gel formation can occur when the cooling system contains an over concentration of high silicate antifreeze and/or supplemental coolant additive. DO NOT use methanol or alcohol as an antifreeze because of its low boiling point. Antifreeze may retain its freeze protection for more than one season but coolant conditioners must be added to maintain corrosion protection. Antifreeze formulated with methoxy propanol, or propylene glycol, is not recommended for this system. WA450-3MC 3-12