Expansion Tank Removal and Installation

Models 520i, 523i, 528i:

REMOVAL
1. Open the expansion tank cap.

* If the engine is hot, place a thick cloth over the radiator cap before opening it to prevent burns from hot coolant and steam. Risk of injury. The cap may only be opened when the coolant temperature is below +90°C.

2. Unscrew the vent bolt (1) and bolts (2). Refer to the accompanying illustration.

3. Remove the upper part and lift the expansion tank up. Refer to the accompanying illustration.

INSTALLATION
1. Replace the O-rings (arrows).
2. Install the expansion tank, secure the upper part and the vent bolt.
3. Fill the system with coolant and bleed air from the system, refer to Coolant Replacement. Coolant Antifreeze Concentration Check. Visual Inspection of Cooling System.
4. Start and warm up the engine and check the connections for leaks.