How to flush a radiator?

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When to flush coolant ?

Over time, radiator coolant loses its properties. As a general rule, it should be changed every 60,000 km or every 2 to 4 years (refer to your service manual for the manufacturer's recommendations). Please note: radiator fluid is toxic.

Useful to know before adding coolant :

Before carrying out any operations, make sure that you have an appropriate receptacle for recycling these liquids and a pair of gloves.

What is a coolant flush ? It consists in changing the coolant in your cooling system; it is something that you can do yourself if you have a little technical expertise in automotive mechanics. We would recommend, however, that you have this done by your garage mechanic, but if you want to do it yourself, the flushing coolant procedure is as follows:

How to flush radiator/ How to flush coolant:

  • The coolant should only be changed when the engine is cool – i.e., when it has been switched off for several hours.
  • Refer to your service manual to find out where the cooling circuit and filling cap are located. Also find out where the radiator's drainage tap is. The radiator is usually near the front of the car next to the engine. Clean the metal slats on the front and back of the radiator that allow air to move throughout with soapy water and a nylon brush (brush in the direction of the radiator fins to remove dirt and grim)
  • Open the filling cap over a container in order to optimally drain the circuit.
  • Position a receptacle under the drainage tap at the bottom of the radiator, then open the valve so that all of the oil in radiator coolant can drain out.
  • We recommend that you wait 30 minutes for the circuit to drain completely.
  • How to add coolant ? Put the radiator drain cap back on and then start to pour coolant into the cooling circuit via the filling cap. You should use 5 L of fluid or more, depending on the vehicle.
  • There will be air in the circuit, so you will need to add the coolant gradually.
    Carry on adding coolant until the level of fluid is just between the minimum and maximum markers.
  • Start the engine, leaving the vehicle in neutral. If you wish, you can turn the heating up to its maximum setting in order to get the new fluid to circulate around the whole circuit.
  • Switch off the engine and recheck the level of fluid. Add more if necessary and then repeat the previous operation until the level has stabilized.
  • A few days after you have filled it up, check the coolant level again.

How to do a coolant flush - Warning: used coolant should not be disposed of down the drain or in the wastewater system: it should be taken to an appropriate place, such as a garage or a waste collection area.