How to Flush a Radiator

A car radiator acts as a cooling system. It should be cleaned and should be free from obstacles to function effectively. Motorists often neglect radiators until something bad happens, this is the reason radiator problems are the most common causes of breakdowns.

Here is how you can flush a car’s radiator, follow the simple directions


  • The car should be parked on a level surface with the engine turned off and the heater switch turned in on position. The engine should be covered to protect from splashes.
  • Remove the radiator car. Turn the tap at radiator’s bottom to let the water go out. The upper and lower radiator hoses should be disconnected.

Flush  Radiator

  • The hoses should be checked for their condition. Replace them it they are soggy or brittle.
  • The old liquid that emerges from the radiator should be checked. If it is clean than it is good and if it is dirty with rust, the system would need a special flushing.
  • The water hose has to be placed on top of the radiator and gently let it flush for some time until the water hopefully runs clean.
  • The hose has to be placed in the reverse flush and bottom radiator outlet. Then it has to be flushed from top again.
  • Remove deposits by Flushing through the engine cooling jacket.
  • Use can of radiator flush for an extremely dirty radiator.
  • Close the radiator car when the flushing has completed, refit the hoses and fill the radiator with coolant.
  • 10. Check the condition of the radiator cap before replacing it. Put a new one if the old one is rusted.
  • 11. Start the engine and let it run while checking the leaks.
  • 12. Take a test drive to check if the coolant system is working properly.
  • 13. When the engine cools down, check the coolant level to know if it further needs topping up.


  • If a radiator leaks, the best option is to take it to a mechanic for repairs or get an exchange unit.
  • A radiator and cooling system should be ideally flushed out after every six months. This will help to avoid blockages
  • If the radiator has a leak, buy a leak sealer can. Put this in the coolant, it is only a temporary measure for small leaks.

The non-sealed radiator should be regularly checked and cleared of leaves.

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