2004 Dodge Durango Owner's Manual - Page 310
2004 Dodge Durango Manual
Page 310 highlights
310 MAINTAINING YOUR VEHICLE WARNING! Never add coolant to the radiator when the engine is overheated. Do not loosen or remove pressure cap to cool overheated engine. The coolant is under pressure and severe scalding could result. Coolant Pressure Cap The coolant pressure cap must be fully tightened to prevent loss of coolant, and to insure that coolant will return to the radiator from the coolant coolant bottle. The pressure cap should be inspected and cleaned if there is any accumulation of foreign material on the sealing surfaces. WARNING! The warning words "DO NOT OPEN HOT" on the coolant pressure cap are a safety precaution. Heat causes pressure to build up in the cooling system. To prevent scalding or injury, do not remove the pressure cap when the system is hot or under pressure. Coolant Level The coolant bottle system provides a quick visual method for determining that the coolant level is adequate. With the engine idling, and warmed to normal operating temperature, remove the cap from the bottle, remove the dipstick and wipe the excess coolant from it. Reinsert the dipstick and remove. Observe the dipstick checking the holes along the stem for coolant. Check the coolant level whenever the hood is raised.