How to Replace Dex-Cool With Regular Antifreeze

Dex-Cool is a type of antifreeze that is supposed to have an extended usage life. It has been used almost exclusively in General Motors vehicles. While GM recommends using Dex-Cool in a number of its vehicles, some consumers have complained that Dex-Cool is a contributing factor in an assortment of cooling system related parts failures, including gasket and water pump failures. Dex-Cool has actually been the target of a class action lawsuit filed by some GM vehicle owners, who claim the coolant cause expensive malfunctions in their vehicles. Due to these reported problems, some GM vehicle owners opt to stop using Dex-Cool in their vehicles.

Things You'll Need

  • Antifreeze
  • Bucket
  • Hose or jugs of water
  • Read your car's owners manual to determine how many quarts of coolant your vehicle holds. This will give you a general idea of how much antifreeze you should expect to get back from your vehicle's cooling system and how much new coolant you need to purchase in order to refill it. Remember that coolant needs to be safely drained into a bucket or jug because it is considered a hazardous substance and is poisonous if ingested by animals.

  • Drain the existing Dex-Cool coolant from the cooling system. You will need to disconnect and drain the cooling system overflow reservoir, then remove the radiator cap and open the radiator drain cock, if your vehicle is equipped with one. If not, or if you can not locate it, you can drain the cooling system by removing the bottom hose from the radiator and allowing all the fluids to drain. Re-attach hose and close the drain cock, then refill the cooling system with water. Allow the vehicle to run for a few minutes, then repeat the draining process to ensure you have flushed all the Dex-Cool from your cooling system.

  • Refill the cooling system with the antifreeze product of your choice. Make sure to mix it with water (if necessary) as instructed by the individual product instructions. You may need to open an air-bleed valve to allow air to escape the cooling system, if your vehicle is equipped with air-bleeds. Check your owner's manual to determine the correct refill procedure for your vehicle and complete all procedures listed in the owner-s manual to refill coolant. Make sure the vehicle gets refilled with the full amount of coolant that the owner's manual indicates it should hold.