Cold Weather Recommendations for On-Highway Diesel Truck Engines Caterpillar

Coolant Recommendations

Usage:

3208 02Z

The following two coolants are used in Caterpillar diesel engines.

Preferred - Cat Extended Life Coolant (ELC) or a commercial heavy-duty coolant that meets the Caterpillar EC-1 specification

Acceptable - Cat Diesel Engine Antifreeze/Coolant (DEAC) or a commercial heavy-duty coolant/antifreeze that meets "ASTM D4985" or "ASTM D6210" specifications

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NOTICE

Do not use a commercial coolant/antifreeze that only meets the ASTM "D3306" specification. This type of coolant/antifreeze is made for light duty automotive applications. Use only the coolant/antifreeze that is recommended.

Note: Caterpillar recommends a 1:1 mixture of water and glycol. This mixture of water and glycol will provide optimum heavy-duty performance as a coolant/antifreeze.

Note: Caterpillar DEAC DOES NOT require a treatment with an Supplemental Coolant Additive (SCA) at the initial fill. Commercial heavy-duty coolant/antifreeze that meets "ASTM D4985" or "ASTM D6210" specifications MAY require a treatment with a supplemental coolant additive at the initial fill. Read the label or the instructions that are provided by the OEM of the product.

Note: These coolants WILL require a treatment with a supplemental coolant additive on a maintenance basis. Regardless of the ambient temperature, the supplemental coolant additive should be maintained between three to six percent. The Caterpillar 4C-9297 Test Strip can be used to help maintain the appropriate concentration of Caterpillar SCA.

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NOTICE

All Caterpillar diesel engines equipped with air-to-air aftercooling (ATAAC) require a minimum of 30 percent glycol to prevent water pump cavitation.

Glycol

For optimum performance, Caterpillar recommends a 1:1 mixture of a water/glycol solution.

Note: Use a mixture that will provide protection against the lowest ambient temperature.

Note: 100 percent pure glycol will freeze at a temperature of −23 °C (−9 °F).

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Table 1
Ethylene Glycol
Concentration	Freeze Protection	Boil Protection
50 Percent	−36 °C (−33 °F)	106 °C (223 °F)
60 Percent	−52 °C (−62 °F)	111 °C (232 °F)

Check the coolant for the concentration of glycol frequently in cold weather with a refractometer type coolant tester in order to ensure adequate freeze protection.

To check the concentration of glycol, use the 1U-7298 Coolant/Battery Tester (DEGREES CELSIUS) or use the 1U-7297 Coolant/Battery Tester (DEGREES FAHRENHEIT). The testers give readings that are immediate and accurate. The testers can be used with ethylene or propylene glycol.

Water

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NOTICE

Distilled water or deionized water is recommended for use in engine cooling systems. DO NOT use the following types of water in cooling systems: hard water, softened water that has been conditioned with salt, and sea water. Damage to the cooling system may result.

Note: If distilled water or deionized water is not available, use water with the properties that are listed in table 2.

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Table 2
Caterpillar Minimum Acceptable Water Requirements
Property	Maximum	ASTM Specification
Chloride (Cl)	40 mg/L (2.4 grains per US gal)	"D512" "D4327"
Sulfate (SO⁴⁾	100 mg/L (5.9 grains per US gal)	"D516"
Total Hardness	170 mg/L (10 grains per US gal)	"D1126"
Total Solids	340 mg/L (20 grains per US gal)	"D1888"
Acidity	pH of 5.5 to 9.0	"D1293"