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This guide provides instructions on how to drain engine coolant (antifreeze) on Mercedes-Benz vehicles. These guidelines are meant to help you drain the coolant on models such as C, E, S, CLS, CLK, ML, GL, R-class, and other models.

Table of Contents


What you will need


Follow this procedure if you need to flush the Mercedes engine coolant or need to replace the radiator or water pump.

  1. Park the vehicle and allow it to cool down.drian mercedes engine coolant
  2. Drive the vehicle up on-ramps. Ensure the transmission is in park and parking brakes are on.
  3. Support vehicle with jack stands.
  4. Pull the hood release under the dashboard and open the hood. Locate the coolant expansion tank in the engine bay. Remove the cap to release cooling system pressure.location of coolant reservoir Mercedes E Class
  5. Remove the undercover right behind the front bumper.raise  vehicleIt is held in place with several 8mm screws. You don't need to remove the cover under the engine.mercedes undercover screws
  6. Place a drain bucket below the radiator on the driver's side.
  7. Unscrew the drain plug at the bottom of the radiator on the driver's side.
    Mercedes Drain Plug
    2008 Mercedes CLK550 Radiator Drain Plug
    The drain plug is easy to identify. On models such as the E-Class W210, the drain plug is red.
    drain mercedes coolant
    Mercedes CLS550 drain plug. Lower left corner of the radiator. Driver side. 
  8. Allow the engine coolant to drain for about 10 minutes.
  9. Tighten the drain plug after all the coolant has drained.
  10. Add the recommended Mercedes engine coolant from the coolant tank. If you are mixing coolant and water, ensure you are using distilled water. Do not use tap water as the chemicals found in drinking water can cause damage.
  11. Start the engine and let it reach operating temperature.
  12. Allow the engine to cool down and check the engine coolant level. Add engine coolant if needed.


  • Do not work on the cooling system if the engine is still hot.
  • Use Mercedes-Benz approved coolant.
  • Mercedes engine also has an engine block drain located on the passenger side of the engine between the exhaust and engine mount. If you want to flush the system thoroughly, you need to drain the coolant in the engine block, as well.


Can I put water in the Mercedes-Benz cooling system?

Using tap water is not recommended. You should use distilled water and engine coolant. Or use a pre-mixed engine coolant.

What color is Mercedes-Benz coolant?

Typically Mercedes engine coolant is either purple or blue. Because every Mercedes model and engine is different, we recommend you look up the correct engine coolant for your Mercedes-Benz in your owner's manual.