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August 22, 2010
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Testing strips use colour codes to indicate the condition of the coolant in different ways.
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Coolants and Additives
A Guide to Good Practices
A good cooling system maintenance program requires regular verification of the quality of the coolant, and measuring the efficiency of the inhibiting agents. The use of the appropriate tools, equipment, and procedures is essential in order to perform this inspection properly.
When a new customer comes into your shop, most of the time you have no references to assess the car’s condition. Just like a doctor would do with a new patient, you perform a general assessment of the vehicle. Once this is done, you convey the results to your customer who will then decide what to do according to your recommendations. The approach used for the cooling system is similar.
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A refractometer is used to verify the opacity of the cooling liquid by measuring the amount of light going through and displays the result on a graduated scale.
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Contaminated coolant
If the coolant is contaminated, or if the inhibiting agents have lost their antifoaming, stabilizing, and anti-corrosion properties, chemical reactions can occur, which may promote limestone build-up and solid deposits of silicates inside the cooling system. These deposits can slow down and even block the coolant flow, which can increase the operating temperature. A contaminated or inefficient coolant cannot properly absorb the heat from the cylinders, and will cause a premature wear of the internal parts of the engine, while a coolant containing too many inhibiting additives can produce acids that could rapidly damage the seals, causing leakages.
Tips from a pro
Neil Munday, a sales representative for Hall-Chem, explains the main steps that need to be performed:
Measuring the pH: In order to prevent electrolysis, it is important to verify the pH level of the cooling liquid every year by dipping test strips into the radiator’s coolant (not in the surge tank) to measure it; the colour of the strip will determine if the coolant is too acid or too alkaline. A normal reading is between 1,200 and 3,200 ppm. Any reading outside this window means that the coolant needs to be replaced.
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The hydrometer measures the density of the coolant by displaying the freezing and boiling points
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Measuring the density of the antifreeze agent: A 50/50 mix of deionised water and pure glycol lowers the freezing point to around -37°C (-35°F) and increases the boiling point to around 110°C (230°F). A reading with a hydrometer—or a strip—will indicate the density or glycol percentage of the coolant. This test can also be done with a refractometer.
Use quality products
Munday points out the importance of using deionised water or premixed coolant when replacing the cooling fluid. “Tap water contains chemicals that are incompatible with phosphates, silicates, and nitrates, which are inhibiting agents found in coolant. Chlorine kills these ingredients as well as the coolant formula, loosens the stabilizing agents, and bakes the coolant residues on the engine’s walls. The use of good quality cooling products will also extend the life of all components: water pump, radiator, seals, hoses, etc.”
www.hall-chem.com | |
François Charron