ASTM D4985 Standard Specification for Low Silicate Ethylene Glycol Base Engine Coolant for Heavy Duty Engines Requiring a Pre-Charge of Supplemental Coolant Additive (SCA)
4. General Requirements
4.1 Ethylene glycol base engine coolant concentrates or prediluted ethylene glycol base engine coolants shall be formulated with ethylene glycol meeting Specification E1177, water, and shall contain suitable corrosion inhibitors, dye, and a foam suppressor. Other glycols, such as propylene and diethylene, may be included in concentrates up to a maximum of 15 % (7.5 % for prediluted coolants) if the physical and chemical properties in Table 1 are met.

4.2 All ethylene glycol base engine coolants shall conform to the general requirements in Table 2.

4.3 Prediluted coolants shall be prepared using deionized water that meets the following requirements:


NOTE 2 - Prediluted coolants are intended for direct addition to an engine cooling system with no further dilution.

This practice minimizes the formation of hard water scale and avoids the introduction of mineral components, such as chlorides and sulfates, which can increase the corrosion rate of aluminum and iron. The use of Type IV reagent water also minimizes interferences that may cause coolant instability or SCA compatibility problems.

4.4 When diluting engine coolant concentrates for actual service, municipal (treated) or a low-mineral content well water should be used (see Appendix X1, Table X1.1).

4.5 Diluted coolant concentrates or prediluted coolants, when mixed with SCA in accordance with the engine manufacturer's recommendations and those on the product label, shall be suitable for use in a properly maintained cooling system in normal service for a minimum of one year (see Appendix X1).

5. Detailed Requirements
5.1 Ethylene glycol base engine coolant concentrate shall conform to the physical and chemical requirements in Table 1 and the performance requirements in Table 3.

5.2 Prediluted aqueous ethylene glycol base engine coolants (50 volume % minimum) shall conform to the physical and chemical property requirements in Table 1. The requirements listed in Table 1 for prediluted coolants are prescribed for the coolant as packaged, without further dilution or adjustment.

5.3 The freezing point ofprediluted aqueous ethylene glycol base engine coolants, as packaged, shall be -36.4°C (-33.5°F) or lower.

5.4 If necessary, adjust the freezing point of the prediluted aqueous coolant to -36.4°C (-33.5°F) with deionized water before proceeding with performance testing.

5.5 Prediluted aqueous ethylene glycol base engine coolants shall conform to the performance requirements prescribed in Table 3, after any needed concentration adjustment.

6. Keywords
6.1 coolant requiring SCA pre-charge; engine coolant; ethylene glycol; heavy duty engine coolant; heavy duty engine service; low silicate engine coolant; prediluted