With cooler weather on the horizon, it's time to be sure your car or truck is ready for its annual wrestling match with old man winter. Of all the seasonal maintenance procedures you can -- and need -- to perform, I think the radiator flush is the most important. You may be thinking, "Duh Matt, it's called 'antifreeze.' You're such a genius." You're right, it seems like the obvious choice. But checking your coolant (or antifreeze, same thing) level and mixture isn't enough. It's super important to clean this system out with a proper flush. Aging coolant can be terrible for your cooling system. I've seen heater cores eaten away with pinholes thanks to lack of cleaning. If you do only one maintenance procedure this year, shame on you, but let it be a coolant flush!