Models 520i, 523i, 528i
Withdrawal
Remove expansion tank cap.
Attention: When the engine is hot, before opening the cap of the expansion tank, in order to avoid burns from hot liquid or steam, cover the cap with a thick rag. Danger of accident! Open the cover only when the coolant temperature is below +90°C.
Remove bleeder plug -1- and screws -2-.
Remove the upper part and pull out the reservoir towards the top.
Installation
Replace sealing rings -arrows-.
Insert the expansion tank, tighten the fastening of the upper part and the bleeder plug.
Fill and bleed the cooling system, see section "Maintenance work".
Warm up the engine and check all connections for leaks.