How to Flush (or Drain and Fill) a Radiator
It’s important to flush out your vehicle’s coolant system at least once each year to prevent corrosion and to flush out sediments that build up within the old fluid.
Flushing the coolant system is pretty easy and doesn’t require any special tools, so if you’d like to save a few bucks and do it yourself, here’s how:
What you’ll need
Pan or bucket
Regular garden hose
Radiator Flush Solution
1. Your vehicle should be cold. Never attempt to flush the coolant system immediately after your vehicle has been running or idling.
2. Locate the radiator (see Routine Vehicle Maintenance: Understanding The Basics – Part 1 ) and remove the radiator cap. Note the hoses to be certain they are firm without any holes. Place the pan or bucket underneath to catch all fluid drainage from the radiator and then loosen the radiator plug located on the bottom side of the radiator. The radiator plug could be a screw plug, drain valve or even a bolt plug. Let the coolant drain from the radiator completely.
3. After all of the coolant has been drained, you’ll replace the drain plug and add radiator flush solution directly into the radiator and then turning on your garden hose, fill it to the top with water. Replace the radiator cap. You can also omit using the flush solution if you like and simply just use water.
4. Start your vehicle and let it run until the temperature gauge inside your car reaches a normal operating level. While your vehicle is running, turn the vehicle heater to its’ hottest position and let it run for about 10 to 15 minutes, keeping the engine running.
5. Turn the vehicle off and let it cool down completely. Never touch the radiator cap or attempt to remove it when the car is hot. If the radiator cap is hot to the touch or very warm, its sill too hot to remove. After the engine has cooled down considerably, open the drain once again and let the fluid run out of the radiator, remembering to use your bucket or pan to catch it all.
6. When the fluid has been completely drained, replace the plug and add new coolant to the radiator. You can use a 50/50 mix of water and coolant or use coolant and water that has already been pre-mixed for you. Don’t forget to fill the coolant reservoir with the same 50/50 mix if needed, as well.
7. Be certain to make sure the radiator cap and plug are tightly secure.
That’s it you’re done!
If you notice any leaks in hoses while you’re flushing, this is a good indicator that they need to be replaced. You won’t get far with a leaky radiator hose.
VERY IMPORTANT! When the coolant is drained, be sure to collect it in a container and keep it away from pets. They may try to drink it, because of its sweet taste and it is poisonous to them.