How to Change Coolant in Your Car

mechanic working on a car
  • 1-2 hours
  • Beginner
  • 30-50
What You'll Need
Your brand of coolant or antifreeze (in a 50/50 mix with water)
Phillips head screwdriver

Many car owners want to know how to change coolant in their cars in order to save money. Regularly changing the coolant in your vehicle is a preventative measure which will, in the long run, help keep your vehicle performing well. If you want to avoid problems with your engine such as overheating and freezing up, then you should learn how to change coolant.

Step 1 - Choosing the Right Area

Where you perform the changing of the coolant is important because antifreeze is very toxic. If you do not have a professional or finished garage, you should take great care where you change the coolant. Look for an area that is covered in gravel and not near any flowing water. Antifreeze is toxic to vegetation and animals.

Step 2 - Getting Ready

When you are parked in an area where you can safely change the coolant, pop open your hood. Make sure that the car is not running and that the engine is cool. You do not want to change the coolant in a car when the engine is hot. The coolant can bubble and spill out of the radiator, causing serious burns.

Step 3 - Removing the Old Coolant

There is no need to rush this process, so always take your time to avoid mistakes. It is important to change the coolant every few months to avoid sediment from building up in the radiator, which can potentially clog the system. Remove the cap from the radiator or coolant reservoir. Climb under the car and look for a screw that is directly under the reservoir where the coolant goes. Make sure you position the bucket directly under this screw. Use the Phillips head screwdriver to loosen the screw. You don't have to remove it completely. Once the coolant begins to dribble out of the hole you can relax until it stops coming out. When it's finished draining, you can climb back under the car and tighten the screw.

Step 4 - Adding the New Coolant

Find the opening to where the coolant goes. Make sure you mix the antifreeze with water according to the instructions on the bottle. Fill the reservoir about half way before stopping. At this point you want to "burp" the engine. Basically, you are trying to get the coolant to circulate a little bit and settle into the system. This also prevents air bubbles in the lines. Turn the car on and let it idle for a minute or two. You can press the gas pedal if you'd like, in order to rev the engine. Turn the car off and top the coolant off until the reservoir is full, then return the cap and tighten.