There are several types of coolant for a Chevrolet Silverado. The older style green antifreeze coolant is good for two years. Then it begins to change and becomes corrosive and should be replaced. The newer Dex Cool antifreeze is orange in color and comes in all the new vehicles. This new and improved antifreeze can be used for much longer periods of time---up to five years or 60,000 miles as long as it appears clean. Every time the cooling system is serviced, a radiator flush should be used first to clean the rust and scale out of the engine.
Pour the cooling system flush in the radiator. If there is not enough room then the radiator has to be drained of some coolant to make room. Start the Silverado and allow it to reach operating temperature. Shut the engine off and give it about 15 minutes to cool down.
Place the catch pan under the lower radiator hose and remove the spring clamp with the hose removal tool or the pliers. Slowly remove the hose so that it does not dump all the coolant at once and make a mess. Let it drain for a few moments after the large part of it has come out. Replace the hose and the clamp. Remove the top clamp and hose at the radiator.
Fill the radiator with water and start the engine, leaving the top radiator hose off. Flush the system out to get rid of all the contaminants left after the engine was flushed. It will take a few minutes for the thermostat to open. Once water starts coming out of the top hose, it has opened. Just keep adding water for about five minutes and then shut the engine off.
Remove the bottom radiator hose once again and allow the water to drain out. Hook up both radiator hoses. Pour two gallons of coolant into the radiator. Top it off with water.
