Car owners who maintain their own vehicles often drain the coolant from an engine block as part of their cooling system maintenance. When you do this, the radiator and engine block are flushed of all old antifreeze and the system is refilled to keep it running smoothly. In very cold climates, you might want to drain the engine block during sub-zero temperatures to keep it from freezing and cracking. Park the car away from children and pets because the antifreeze solution is hazardous if ingested. Also, be sure your car engine is cool before beginning
Park the car and let the engine cool. Put on the emergency brake. You might want to use ramps for easier access, but it is not required.
Remove the radiator cap. Place a container that will hold at least two gallons beneath the radiator and open the radiator petcock. When all the coolant has drained, close the petcock.
Locate the engine block drains. Car models vary as to number and location of block drains. Look on either side of your engine block for one or two drain plugs. Place a pan beneath the drain and open it with a socket wrench.
Use a nail or bent wire to check the drain for sludge when the coolant stops flowing. Replace the drain plug when you are satisfied the coolant has all drained, and refill your car's system with fresh antifreeze.
