MAINTENANCE 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. NOTICE: Do not mix types of antifreeze solutions. Mixed solutions make it impossible to determine the protection against freezing. Antifreeze containing sealer or anti-leak additives should NOT be used in this system. Sealer or anti-leak additives will cause plugging problems in the cooling system. WARNING Use extreme caution when adding coolant to a hot radiator to avoid being burned.
Wear gloves and goggles and keep face away from the filler neck. Check the solution periodically and at normal operating temperature, to be sure the cooling system has sufficient protection against freezing. An antifreeze concentration greater than 68% will adversely affect antifreeze protection and heat transfer rates. Antifreeze concentrations between 68% and 100% actually have a higher freezing point than a 68% antifreeze concentration as well as reduced heat transfer rates, and should not be used. REMARK A 100% antifreeze solution will cause severe corrosion in the cooling system and if not detected will cause radiator and oil cooler core damage.
Use a water/antifreeze solution as described in the following table for freezing protection. The following table shows the approximate percentage of antifreeze solution required for various temperatures. In tropical climates where antifreeze availability may be limited, use a corrosion inhibitor or supplemental coolant additive (SCA), to protect the engine cooling system. 20.7.4 SUPPLEMENTAL COOLANT ADDITIVES 1. All supplemental cooling system additives, including those in antifreeze solutions, become depleted through normal operation.
If the coolant additives in antifreeze are allowed to become depleted, the antifreeze becomes corrosive and attacks and coats the metallic surfaces of the cooling system which reduces heat transfer. Cooling system conditioners which contain these additives must be added to maintain corrosion protection. 3-14 WA420-3MC Approximate Freezing Point Percentage of Antifreeze Concentration by Volume Specific Gravity at 16 0 (+32 -7 (+20 -12 -18 -23 (-10 -29 (-20 -34 (-30 -40 (-40 -46 (-50 -51 (-60 -57 (-70 -62 (-80 -68 (-90 -69 (-92 0 15 25 33 40 45 48 53 56 59 62 65 67 68 1.000 1.025 1.040 1.053 1.062 1.070 1.074 1.080 1.083 1.088 1.092 1.095 1.097 1.098