The decision by engine manufacturers to use lighter materials, such as aluminum, created many positive implications for the heavy duty vehicle market. Chief among them is improved fuel economy, reduced emissions, and the ability to haul heavier loads.
With these overall positives came one significant roadblock: traditional heavy duty antifreeze/coolants (AF/C) designed for engines constructed of cast iron, copper, or brass did not necessarily play well with aluminum. The culprit was a new heat-exchange manufacturing process called “controlled atmosphere brazing” (CAB). CAB improves the efficiency of the heat exchanger manufacturing process, but it leaves behind some amount of residual brazing flux, which can react with certain AF/C inhibitors. The particular issue is with the inhibitor nitrite, which is used to protect liners from cavitation damage.
To ensure complete protection, Prestone has responded to this challenge with the development of a new nitrite-free organic acid technology (NF OAT) AF/C with a proprietary inhibitor package. Called Cor-Guard, this additive can effectively eliminate the negative effects of the CAB manufacturing process. Cor-Guard enables the NF OAT AF/C to instantly bond to the cooling-system components, significantly lowering the level of surface-area corrosion and erosion below that of other similar AF/C fluids. This new formulation is also designed to seek out and protect hot spots from cavitation corrosion, which are notorious points for engine damage.
Additional benefits include:
- Improved cavitation control
- Improved compatibility with the elastomers in cooling-system seals and gaskets
- Improved AF/C formula stability for improved overall performance
- Maintains proper engine temperatures helping preserve oil viscosity, which improves engine life and performance with optimized MPGs
- Improved coolant stability for older AF/C that is topped off with Cor-Guard
Since different engine manufacturers have varying specifications for AF/C selection and usage, before using Prestone Command with Cor-Guard, it is critical that fleets ensure the cooling system is properly prepared for the product. It is always advisable to follow the preferred maintenance practices of the OEM when it comes to selecting an AF/C.
Information provided by Colin Dilley Ph.D., vice president of technology, Prestone Products Group
