Dodge 2009 Charger SRT8 Owner's Manual page 363

Cooling System Pressure Cap
The cap must be fully tightened to prevent loss of engine
coolant (antifreeze), and to ensure that engine coolant
(antifreeze) will return to the radiator from the coolant
recovery bottle.
The cap should be inspected and cleaned if there is any
accumulation of foreign material on the sealing surfaces.
MAINTAINING YOUR VEHICLE 361
WARNING!
The warning words "DO NOT OPEN HOT" on
the cooling system pressure cap are a safety pre-
caution. Never add engine coolant (antifreeze)
when the engine is overheated. Do not loosen or
remove the cap to cool an overheated engine. Heat
causes pressure to build up in the cooling system.
To prevent scalding or injury, do not remove the
pressure cap while the system is hot or under
pressure.
Do not use a pressure cap other than the one
specified for your vehicle. Personal injury or en-
gine damage may result.
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