Mercedes-Benz Radiator Replacement Guide

• Mercedes Radiator
• Mercedes Engine Coolant
  • Between 3 and 4 gallons. Check capacity in your owner's manual.
  • Mix Anti-freeze coolant and distilled water in a 50-50 ratio.
• May also need Mercedes Transmission Fluid - 1qt

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.

• Screwdriver
• Work gloves
• T25 Torx
• 10mm wrench
• Needle nose pliers
• Oil pan

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.

Procedure

1. Park the vehicle and allow it to cool down.
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.
5. Pry out the two plastic pins at each end of the top radiator bracket.
6. Remove the upper radiator support.It 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.
8. Remove the top radiator support bracket.
9. Carefully release the hood release cable from the top bracket. It is clipped to the bottom of the top radiator bracket.
10. Locate the electrical connector on the back of the cooling fan.

    

    Press the connector and pull it to disconnect it.
11. Remove two U clips at each top corner of the radiator.These clips can be removed by prying them up with a screwdriver.
12. Slide the radiator colling fan up.Look 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.
14. Disconnect all the coolant hoses.Once the C clips are in the unlock position, the hoses can be removed by pulling out on the hose. 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.Pull out the hose to disconnect it.
16. Move the C clips for the transmission cooling lines to unlock position. Pull out the transmission cooling line.Oil may drip from the lines. Have an oil pan ready to collect oil.
17. Squeeze the plastic retainers with needle-nose pliers to unclip the condenser from the radiator.The retainers are on both sides of the condenser.
18. Pull the condenser up slightly to unlock it from the radiator brackets located at the condenser/radiator's bottom.
19. Carefully lift the radiator.Make 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.

Notes

• 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.