9 Easy Steps to Bleach Your Car's Cooling System

This guide will start by making sure that your antifreeze is in good condition. It is important to use only the right coolant as directed by your manufacturer. You could endanger your engine by using the wrong coolant!
You can check the repair manual to determine which coolant is best for you or speak with your dealer.
If the anti-freeze concentrate coolant is concentrated, you should mix it with half water and half coolant.
For the best instructions, make sure you read the coolant description. You must ensure that your coolant mixture is appropriate if you are located in cold countries. Coolant that freezes inside your engine can cause it to fail.
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The first step to get a better result, but one that is not often done by many is raising the vehicle's front. This will make it easier to get air out, particularly if you have a radiator filling cap. If you have a car with an external expansion tank installed in the engine’s rear, this may not be necessary.
To raise the car’s front, you could either use a floor jack or put the car on a steep hill with the front upwards.
When raising your car with a floor jack, always also use Jack Stands to prevent any accidents.

Now when the car front is raised, it’s time to fill your coolant as much as possible. When you're adding coolant to your engine, make sure they are open if there is an air bleed valve. If coolant starts to flow out of them, you can close them.
Antifreeze can be toxic and should not flow down into your floors or roads. Your local environment assessment should receive all coolant. Be aware that coolant can cause severe illness in animals if it is consumed. Be careful when applying anti-freeze. Once you've filled the coolant to its maximum capacity, move on to the next step

Now, you should start the engine. A friend can help you do this. The water pump can push coolant through the radiator when you turn on your engine. A tool such as this is installed to your radiator in order to prevent it from happening.

Once you've started the engine, turn up your climate control heat. It depends on the car, but many cars use a valve that will restrict the coolant from flowing inside the car’s thermal pack if the climate control is set to cold.
Others cars will redirect coolant flow and airflow. No matter which model you have, it’s an easy step to put your climate control to the MAX heat.

Let your friend get in the car, and then let him rev your engine up to 3000-4000 RPM. The coolant could flow from the radiator if the spill tool is not used. While you work in the system, keep the RPMs constant. While working in the cooling system, ensure that it does not get too hot.

Now, your friend can rev the engine a little. You can then loosen the coolant valves. It is important that the coolant temperature does not exceed 85 degrees. If it is too hot, you could endanger your vehicle. Be attentive to any coolant temperature peaks and coolant leaks at this point. Close the bleed valves until coolant is removed from them. Continue this several times, until the coolant leaves them.

Close your air bleeding valves. Restart your engine and let it idle for a second time. These steps should be repeated until the heat gets inside your car. Reattach the radiator cap. You should remove the radiator cap if your coolant temperature exceeds 90c. Warning: Hot coolant can cause damage to you if it’s not used with care.
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You should now make sure that you can’t find any leaks after your repair. You can now take the car for a lengthy test drive, if it looks okay. You should be careful with your coolant temperature and ensure the car does NOT overheat during this test drive. You don't want your head gasket blowing if you overheat the car. You should check all functions as well the temperature control.

Your test drive was successful if there were no temperature spikes or unusual behavior. Verify that there are no coolant leaks.
After that, let the vehicle rest for at least an hour. Then, take another test drive. Follow the exact same steps and inspect for coolant levels and leaks.
Your repair should be completed after you have followed these steps. You can continue troubleshooting if you notice any unusual behavior.
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