How do you change the engine coolant in a 2004 chevy silverado 3500 (6.6L duramax diesel)?
The radiator drain is on the bottom of the radiator opposite the lower radiator hose. Drain this into a bucket. The engine block has its drain plug located just below the freeze plugs on the engine block. Remove this bolt and drain the coolant into a bucket. Recycle of safely dispose of the coolant. It is often toxic to animals. To refill, close the radiator drain valve and replace the engine drain plug(s). Pour 1/2 the capacity of the engine coolant system (that is in your manual) into the radiator. Top up the radiator with water (distilled is best but not necessary). Start the engine and let it come to temperature (this allows the thermostat to open and replace the coolant in the engine which was drained earlier. When the upper radiator hose becomes warm to the touch, the thermostat will have opened and allowed coolant to flow from the radiator into the engine so with the engine still running, CAREFULLY loosen the radiator cap to its first unlocked position. You may get steam release
