Even after moving from NOAT (Nitrite Organic Acid Technology) to NF OAT (nitrite free extended life coolant), some heavy duty OEMs have kept coolants the same color. Unaware of the change, fleets have been incorrectly mixing coolant technologies, potentially putting their fleets’ cooling systems at risk of a drop in protection against corrosion and cooling system failures.
While some manufacturers do an exemplary job of differentiating coolants with color and cooling system stickers, color alone is no longer the definitive measure by which to identify a fluid type. If an AF/C (antifreeze/coolant) type isn’t known, the fluid should be tested immediately to determine its exact technology to avoid damage and the correct coolant technology to use.
Contamination
What makes the issue around color dyes even more complicated is that these coolant technologies are not completely compatible. Therefore, cross contamination can cause additional corrosion problems.
Conventional IAT (Inorganic Additive Technology) requires the periodic addition of nitrite-containing supplemental coolant additives (SCA) in order to maintain effective corrosion protection. NOAT requires an “extender” to maintain the correct inhibitor levels.
Technicians have continued to add SCA and spin on filters that release inhibitors to what they believe is IAT, but are actually NOAT or NF OAT formulas. To further complicate this is the misuse of OAT extenders into the various coolant technologies.
All of these combined issues have created a growing need for skilled technicians to identify AF/C technologies in order to properly maintain fleet cooling systems.