Operation CHARM: Car repair manuals for everyone.

Coolant: Testing and Inspection

NOTE: The cooling system factory fill is a mixture of 50% Ethylene Glycol based antifreeze and 50% water.

1. Using a suitable hydrometer, measure antifreeze concentration in the radiator when the engine is cool.

NOTE: If the cooling system has recently been serviced, allow coolant to circulate for at least 20 minutes before taking hydrometer reading.

2. Properly mixed coolant will protect the cooling system to -37°C (-35°F). If the freeze protection is above -28°C (-20°F), drain enough coolant from the cooling system to allow room to add antifreeze to achieve adequate protection.