how to fix a leaking coolant reservoir in my BMW 5 Series F10/F11 (2010-2017)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the engine is cool before beginning work.
• Disconnect the battery to prevent any electrical issues.

2. Remove the Coolant Reservoir

• Tools Required: Socket set, pliers, coolant catch pan.
• Using pliers, carefully loosen and remove the clamps securing the hoses to the coolant reservoir.
• Disconnect the hoses and allow any remaining coolant to drain into the catch pan.
• Remove any mounting bolts or clips securing the reservoir to the vehicle.
• Carefully lift the reservoir out of its mounting location.

3. Inspect and Clean

• Inspect the reservoir for cracks or damage; if damaged, replacement is necessary.
• Clean any residue or debris from the mounting area and hoses.

4. Install New Coolant Reservoir

• If the reservoir is damaged, replace it with a new one.
• Parts Required: New coolant reservoir, new clamps (if necessary).
• Position the new reservoir in place and secure it with mounting bolts or clips.
• Reconnect the hoses and secure them with clamps.

5. Refill Coolant

• Fill the reservoir with the appropriate coolant mixture (refer to the owner’s manual for specifications).
• Fluid Type: BMW-approved coolant, typically a 50/50 mix with distilled water.

6. Bleed the Cooling System

• Start the engine and allow it to reach operating temperature.
• With the heater set to maximum, open the bleed valve (if equipped) to remove air from the system until coolant flows without bubbles.
• Close the bleed valve and check the reservoir level, adding more coolant if necessary.