Keeping your truck in good running condition for years is a series of simple, do-it-yourself maintenance operations. Among the easiest is flushing your radiator. The benefits of doing so are numerous, and include keeping your cooling system healthy and efficient.
Park your truck somewhere with good drainage on a more or less level surface. Usually, parking it on the street with one side's wheels up on the curb will get the vehicle level and give you enough room to work underneath it. Wait until the engine is cool.
Open the radiator cap, and place the drain pan under the radiator's drain valve petcock. Attache the hose to the drain valve, and loosen the petcock until the fluid starts to drain.
Locate and remove the coolant overflow reservoir, and empty it into the drain pan or one of the buckets. Wash it thoroughly, including the hose that runs into it from the radiator. Replace it when you're done.
Close the petcock, and fill the radiator using the garden hose. Start the engine. While the engine is warming up, remove the drain pan from underneath the truck, and empty it into a bucket. Replace the pan.
Watch the temperature gauge carefully. It will rise to about halfway, then drop a bit. When the needle drops a bit, you know that the thermostat has opened up and the fresh water is now circulating through the cooling system. Shut the engine off, and open the petcock again. This time, the fluid will be hot, so use extreme caution.
Again, run water from the garden hose through the radiator, but this time, leave the petcock open and allow the radiator to flush until the water runs clear into the drain pan. Periodically empty the pan into a bucket. For a more thorough cleaning, run the engine again with just garden hose water, and drain and flush until it all runs clear out of the radiator.
Tighten the petcock, and fill the radiator with a 50/50 coolant/water mixture. At this point, use only the distilled water to prevent any dissolved minerals in tap water to deposit in your system.
Run the engine again, and let it get to operating temperature; then shut it off. Wait for the engine to cool, then top off the radiator again with distilled water. Fill up the reservoir tank with water until it reaches the full mark, and replace the cap.
