Whenever a fluid is in contact with metal, an electrochemical degradation takes place, which results in a higher than normal level of acid present in any given fluid. This higher acid level, if left unchanged, can result in very costly repairs. As a result, it is recommended to flush your cooling system, and most importantly pH balance your antifreeze at least once every 2 years or 30,000 miles. This will help reduce the acid level and extend the life of your radiator, heater core, water pump, head gaskets, freeze plugs, radiator and heater hoses.
Why is it important to have your cooling system flushed by a knowledgeable repair shop with all the right equipment? Why can’t you do it yourself?
You have probably heard many times that your cooling system should be -35 degrees, and you wonder why, when it never gets that cold. The reason for this is due to many different factors. The first factor has to deal with water and why water is an important part of the cooling system. Water is the best conductor of heat because the molecules are spaced far apart letting the heat from the engine to move into the water very easily. The problem with water is that it is very corrosive when in contact with metal and can freeze. Ethylene glycol silicone based antifreeze is added to the water to protect the metal, to keep the water from freezing, and to lubricate only the moving parts in the cooling system (i.e water pump, thermostat).
So why not just use 100% antifreeze? If you use 100% antifreeze, the engine may overheat in hot weather with or without the air conditioner on. The molecules in the antifreeze are packed tightly together and are unable to remove the heat from the engine as efficiently as water. The condenser for your car’s air conditioning operates much hotter than the radiator; that’s why it is placed in front of the radiator. The radiator dissipates the heat from your air conditioning condenser, thus making the coolant even hotter!
With today’s new computer controlled engines the coolant temperature is most important. The temperature sensor tells the computer, along with other sensors, how to adjust the fuel mixture and ignition timing. This may affect engine performance and efficiency. For the best heat removal and metal protection, 50% water and 50% antifreeze is desired. The proper mix is determined by checking the coolant level: -35 degrees equals 50/50. The problem comes when the pH of the water is 7.0 to 7.2 and antifreeze pH is 10.5 right out of the gallon. A 50/50 mix of water and antifreeze would have a pH factor of 8.75. This level is too acidic for today’s cooling systems. The recommended pH level should be between 9.0 and 10.5; this level greatly reduces the acid content that together with electrochemical reaction of dissimilar materials causes electrochemical degradation.
To correct the above condition, you need to power flush your cooling system by continuously forcing the coolant under pressure through the engine, radiator, and heater core in both directions at different times. While the coolant is being forced through the system it is also going through a 25 and 5 micron filters to remove all contaminates from the coolant. Once this is done, antifreeze or water is added to the system while circulating to bring it to the desired -35 degrees throughout the system evenly. We then add a pH concentrate while still circulating the coolant to evenly reach a pH level of 10.5 throughout the system. We stop at 10.5 pH because over time, as the hot coolant flows through the system, it will slowly become more acidic as described above. The coolant should stay within the safe range of 9.8 to 10.5 pH level about 2 years or 30,000 miles. We also pressure test the system for leaks, clean the recovery bottle and test the radiator cap to see if it holds the proper pressure.