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This guide provides instructions on how to replace the radiator on Mercedes-Benz vehicles.

The majority of the pictures in this guide are from an E-Class. These instructions should help you replace the radiator on Mercedes-Benz models such as C, S, ML, GL, GLK, GLE, GLS, etc.

Replacing the radiator on a Mercedes-Benz is easy and takes about two hours.

Table of Contents


What you will need

Below is a list of parts and tools that you will need to change the radiator on most Mercedes-Benz vehicles.

Most Mercedes have the transmission cooler integrated into the radiator. When you disconnect the transmission line, you may lose up to 1 quart of transmission fluid.

Before you start

  • Allow the engine to cool down. Do not work on a warm or hot engine.
  • Disconnect the negative battery terminal.
  • Secure the vehicle with jack stands.
  • Enure parking brakes are engaged, the shifter is in the park position, and rear wheels are blocked.


  1. Park the vehicle and allow it to cool down.park mercedes and let it cool down before you change the radiator
  2. Raise the front wheels and secure the vehicle with jack stands.
  3. Remove the bottom engine cover. It is held in place by 8mm screws.
  4. Open the drain plug on the driver's side of the radiator and allow the engine to cool down. Make sure to have a drain pan under the radiator. In some models, the drain plug is red.Mercedes coolant drain plug
  5. Pry out the two plastic pins at each end of the top radiator radiator bracket
  6. Remove the upper radiator support.Mercedes top radiator support bracket removalIt is held in place with three T25 bolts on each side. On some models, such as CLS and CLK, you may need to remove the front grill as well.
  7. Disconnect the wires from the horn.disconnect mercedes horn
  8. Remove the top radiator support bracket.Remove Mercedes Top Radiator Bracket
  9. Carefully release the hood release cable from the top bracket. It is clipped to the bottom of the top radiator bracket.hood cable
  10. Locate the electrical connector on the back of the cooling fan.
    Mercedes Cooling Fan Connector
    Mercedes E550 Cooling Fan Connector  Location - Passenger side, behind the fan. 
    Press the connector and pull it to disconnect it.
  11. Remove two U clips at each top corner of the radiator.Mercedes Coolaing Fan BracketsThese clips can be removed by prying them up with a screwdriver.Mercedes Cooling Fan U clip removed
  12. Slide the radiator colling fan up.Mercedes cooling fan removedLook at the back of the cooling fan for hoses that may prevent it from coming up. If any of the hoses prevent the fan from moving up, move the hoses out of the way. At the bottom, the cooling fan slides into two channels.
  13. Open the C clips on all of the coolant hoses. The C clips need to be pulled out slightly. It doesn't need to be removed.Mercedes radiator hose connector
  14. Disconnect all the coolant hoses.mercedes radiator hoseOnce the C clips are in the unlock position, the hoses can be removed by pulling out on the hose.replacing mercedes engine radiator cracked If the hose refuses to come off, use a flathead screwdriver to pry out the hose. Be careful not to puncture the radiator hoses.
  15. Use a screwdriver to loosen the clamp for the expansion tank hose.mercedes expansion tank hosePull out the hose to disconnect it.expansion tank hose disconnected
  16. Move the C clips for the transmission cooling lines to unlock position. Pull out the transmission cooling line.disconnect mercedes transmission fluid line from radiatorOil may drip from the lines. Have an oil pan ready to collect oil.Mercedes C clip  transmission line
  17. Squeeze the plastic retainers with needle-nose pliers to unclip the condenser from the radiator.Mercedes Condenser RemovalThe retainers are on both sides of the condenser.mercedes condenser bracket
  18. Pull the condenser up slightly to unlock it from the radiator brackets located at the condenser/radiator's bottom.condenser bracket mercedes benz
  19. Carefully lift the radiator.Mercedes radiator replacementMake sure to close the drain valve before you remove the radiator. If the radiator drain valve is left open, the coolant left in the radiator will spill as you lift the damaged radiator.
  20. Install in reverse order. Make sure to reinstall the rubber grommets. The rubber grommets sit on the frame and fit on the bottom of the radiator.
  21. Add 50/50 engine coolant from the expansion tank.
  22. Check transmission fluid level. On Mercedes-Benz with 722.6 (5 speed) transmissions, you will need dipstick part number 140589152. On Mercedes-Benz, with 7-speed transmissions, you will need a 722.9 transmission fill adapter.


  • Discharging the air conditioner system may be required on some models.
  • Removing the engine cover and engine air duckings will make replacing the radiator easier.
  • Run the vehicle until it reaches operating temperature. Allow the engine to cool down and recheck the engine coolant level.