How to do a Coolant Flush

Coolant Flush is the Process of taking out the old coolant and replacing it with new one. There is a manufacturer suggested interval for doing this , that you can find in the manual or online.  Over time the coolant gets polluted with contaminants and decreases the cooling property , this there is the need for replacing the coolant with new one.  First thing first - Make sure you identify the coolant in your car (see user manual) and get the same type either from the parts store or from the Dealers' Parts section. Also get distilled water to prepare the coolant mix How do you drain the old coolant ? - Fortunately most cars have a little drain plug on the bottom corner of the radiator , it is usually a plastic knob that you need to turn a few times and the coolant starts draining through a hole at the bottom. Park the car in a level space and  let it cool a bit , then remove the drain plug while positioning the container to drain. come back up and remove the radiator cap so that air can enter the system to easy up the draining. You can collect the used coolant in old milk/water gallon jars and dispose as per local re-cycling dates. Make sure to keep these away from kids and pets. Pets have a tendency to be attracted to coolants.

Now prepare the new coolant by mixing the distilled water to the coolant in a 3rd container in the ratio suggested by the manufacturer. It is usually 50/50 for normal climates and more for extreme colds , See the coolant jar label for the correct ratio to mix. Some times the generic coolant can be pre-mixed already with water. I stay away from pre-mixed coolant and just by the regular ones and add my own distilled water.

Make sure the drain plug at the bottom is back tighten back. Add the fresh coolant mixture thru the radiator cap slowly , once filled wait a few seconds for it flow down and then add again , repeat this process till the radiator will not take more coolant.

Now Add coolant into the reservoir tank and fill to level. Put the radiator cap back on and run the car for 30 seconds. Come back and remove the radiator cap and add more coolant and also top the reservoir tank if it is below level . Repeat the process one more time and you should be done. Look for any leaks.

Warning :- Do not turn the engine one by mistake , till the coolant is completely filled.  Even a 30 second without the coolant can cause permanent damage to the engine.

POST Replacement :- Like with a Oil change , after regular driving after a week , check the coolant levels one more time to make sure everything is ok.

The advise here is the basic idea : Since each car is different , As always refer to specific instructions online or from the factory manual on the correct way to do it. For example in some cars after the  first round of filling , you need to turn the engine on and also turn the heater on , then add more coolant.