Coolant
MORE THAN JUST A COOLANT
Our guest speaker for the November 1996 meeting was John Elfebein and offsider Andrew from Deville Australia, the country's largest Coolant manufacturer. The plant is situated in Adelaide and is fully automated. The only other plant that manufactures Coolant in Australia is ICI in Sydney. The product that Deville make is sold under the brand name of Tectaloy.
What a Coolant does is basically forms a film to protect your cooling system components by a bonding and coating process that coats the whole system with a micro thin protective film. The Coolant should have enough reserve inhibitors circulating in the system to repair and maintain this film for the life of the Coolant. This film acts as a barrier to normal corrosion and insulates the metals from electrochemical corrosion. This form of corrosion is caused by a electrical current flowing between different metals, or by some form of electrical component that is shorting out through the cooling system.
To counter this Tectaloy make a stray current detector. Good Coolants should have good anti foaming properties. When Coolants foam it affects the operation of the water pump, by creating air bubbles, this also affects the cooling system to dissipate heat and overheating is likely. Secondly foaming can cause more corrosion called cavitation corrosion or erosion, it forms in high turbulence areas, such as around the water pump. A quick test to check a products anti foaming properties is to shake the container, there should be almost nil, 5 seconds is the maximum limit for the foam to disappear.
Most of the modem Coolants now contain Ethylene Glycol mixed with anti freeze, boil, foam, corrosion additives, they should carry the Australian Standard number of 2108-84. Because all Subaru engines are all aluminium it is important to use a good quality Coolant and change it regularly. Some do's and dont's - when changing Coolants, always use a flush out first never mix different brands of Coolant, use a complete fill Coolant that is pre mixed, don't wash old Coolants down the drain, as they contain heavy metals, from the many different metals that make up today's engines, take it to your local radiator service station.
David Martin SC180
Note: A concerned reader subsequently wrote to express a contrary opinion about using non-genuine coolants in Subarus. See Coolant Caution for details.
Disclaimer: Technical information given or disclosed in this website is given with the best intent and is advisory only. No responsibility is taken by the the Subaru 4WDrive Club of Queensland or its members for any damage or injury caused by any vehicle modifications made, or by the use of any products or the adoption of any procedures mentioned in this website.