How to Drain a Radiator

While it may seem relatively simple to drain a radiator, care must be taken to protect the engine compartment, the environment and those around you. Whether you're flushing a dirty radiator or exchanging it for a new one, take the time to perform the procedure safely and correctly.

Things You'll Need

  • Plastic container
  • Safety goggles
  • Engine cover
  • Park the vehicle on level ground before you drain the radiator. This will prevent coolant and anti-freeze from running down the incline into gutters, flowerbeds or anywhere that animals might come in contact with it. Remember, these fluids taste sweet to animals such as dogs and cats, but are also very toxic.

  • Allow the engine to cool for several hours before you attempt to drain the radiator. The fluid inside the radiator increases in pressure when it is hot, and opening the radiator cap while an engine is still warm could cause serious injury to you and others.

  • Disconnect the battery before you drain a radiator. This will ensure that the electrical fan in front of the radiator doesn't turn on while you're working.

  • Find a suitable plastic container to store the radiator fluid before you drain it. Remember, you want to avoid having any of the fluid splash around or land on the ground if possible.

  • Place an engine cover, such as an approved blanket or tarp, over the entire engine compartment, leaving only the area around the radiator exposed. This will prevent anti-freeze and coolant from splashing all over the engine block.

  • Open the radiator cap, which is located at the top of the radiator. This will help with the flow of liquid when you open the radiator plug at the bottom.

  • Stick the plastic container underneath the radiator plug, which can be found at one of the bottom corners of the radiator. Remove the plug and allow the radiator fluid to empty into the container.

  • Leave the container in place until the fluid has stopped dripping. You may want to use a garden hose to flush cold water through the radiator to remove engine deposits and debris.

  • Re-install the radiator plug, and refill the radiator with coolant or anti-freeze to the recommended level of the vehicle manufacturer. Screw the radiator cap back on, reconnect the battery, remove the engine cover and check for leaks in the radiator. Turn the engine on, and double-check for leaks.

  • Take the used radiator fluid down to a local recycling center for proper disposal.