Coolant: Testing and Inspection

DIAGNOSIS AND TESTING - COOLANT CONCENTRATION TESTING
Coolant concentration should be checked when any additional coolant was added to the cooling system or after a coolant drain, flush and refill. The coolant mixture offers optimum engine cooling and protection against corrosion when mixed to a freeze point of -37 °C (-34 °F) to -46 °C (-50 °F). The use of a hydrometer or a refractometer can be used to test coolant concentration.

A hydrometer will test the amount of glycol in a mixture by measuring the specific gravity of the mixture. The higher the concentration of antifreeze/coolant, the larger the number of balls that will float, and higher the freeze protection.

A Refractometer, Special Tool 8286, will test the amount of antifreeze/coolant in a coolant mixture by measuring the amount a beam of light bends as it passes through the fluid.

CAUTION: Do not mix types of coolant-corrosion protection will be severely reduced.