2005 Dodge Durango Owner's Manual - Page 324

324 MAINTAINING YOUR VEHICLE WARNING! Exhaust gases can injure or kill. They contain carbon monoxide (CO) which is colorless and odorless. Breathing it can make you unconscious and can eventually poison you. To avoid breathing CO, follow the preceding safety tips. Cooling System Inspection Check engine coolant (antifreeze) protection every 12 months (before the onset of freezing weather, where applicable). If coolant is dirty or rusty in appearance, the system should be drained, flushed and refilled with fresh coolant. Check face of radiator for any accumulation of bugs, leaves, etc. If dirty, clean the radiator core by gently spraying water from a garden hose at the back of the core. Check the coolant bottle tubing for condition and tightness of connection at coolant bottle and radiator. Inspect the entire system for leaks. With the engine at normal operating temperature (but not running), check the coolant pressure cap for proper vacuum sealing by draining a small amount of coolant from the radiator drain cock. If the cap is sealing properly, the coolant will begin to drain from the coolant bottle. Do not remove the pressure cap when the cooling system is hot.