Appendix B - General Coolant Information

SLC Antifreeze Coolants

These products are available as Fully Formulated and Phosphate-Free. They are commercially available from Detroit™ (recommended) and other manufacturers as either concentrated antifreeze or as pre-mixed antifreeze. The pre-mixed antifreeze is ready to use, while the concentrated coolant must be mixed with water prior to use. All fully formulated coolants used must also meet Detroit 93K217 specification.

ELC Antifreeze Coolants

EG and PG based antifreeze coolants contain Organic Acid Technology (OAT). These coolants require less maintenance over the useful life of the engine.

ELC antifreeze coolants are available as either concentrated or pre-mixed formulations. Concentrated antifreeze coolants should be mixed at 50% (50% antifreeze/50% water). These types of coolants should not be mixed with SLCs. If an ELC antifreeze coolant and SLC antifreeze coolants are mixed, damage may not result, but the long-life advantages of the ELC antifreeze coolant will be lost. In this event, the coolant should be re-inhibited with OAT inhibitors and confirmed by analysis or else it must be maintained as an SLC antifreeze coolant.

Water-Only Coolants (Series 50, 55 and 60 only)

In warm climates where freeze protection is not required, water only with corrosion inhibitors is approved for use. Water-only systems need to be treated with the proper dosage of corrosion inhibitors. Detroit™-approved SCA or ELC corrosion inhibitors must be added to the water to provide required corrosion and cavitation erosion protection.

Mixing Ethylene Glycol or Propylene Glycol Antifreeze and Water

It is highly recommended to use a pre-mixed 50/50 antifreeze coolant. However, if a concentrated Ethylene Glycol or Propylene Glycol antifreeze is purchased, mix the antifreeze with water meeting the required quality standards and fill the cooling system. See water requirement below for quality standards. If a pre-diluted coolant is purchased, simply fill the cooling system.

For best overall performance, a coolant consisting of 50% concentration of antifreeze (50% antifreeze, 50% water) is recommended. An antifreeze concentration of over 60% (60% antifreeze, 40% water) is not recommended due to poor heat transfer, reduced freeze protection, and possible silicate dropout. An antifreeze concentration below 40% (40% antifreeze, 60% water) offers too little freeze and/or corrosion protection and is not recommended.

WATER REQUIREMENTS

Distilled or de-ionized water, which eliminates the adverse effects of minerals in tap water, is preferred. High levels of dissolved chlorides, sulfates, magnesium, and calcium in some tap water causes scale deposits, sludge deposits and/or corrosion. These deposits have been shown to result in water pump failures and poor heat transfer, resulting in overheating. If tap water is used, the mineral content in the water must be below the maximum concentration listed in the table below.

Fig. 1, Procedure To Evaluate The Quality Of Water

Recycled Antifreeze

Antifreeze coolant made with ethylene or propylene glycol recycled by reverse osmosis, distillation, and ion exchange and properly re-inhibited to meet ASTM D6471 or D6472 requirements has been demonstrated to provide service equivalent to virgin antifreeze. Recycled antifreeze coolants of these types are preferred. However, suppliers of these recycled glycols must provide evidence the product is free of contaminates listed below:

• Acetates
• Acetone
• Ammonia
• Boron
• Ethanol
• Formates
• Glycolates
• Ketones
• Nitrate
• Nitrite
• Phenols
• Phosphorus
• Silicon
• Toluene

Other recycled coolants, especially coolants recycled through filtration processes, are not recommended.