Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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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.