问：我有一个冷却液泄漏...最近更改了扩展箱...现在我在散热器2008 BMW 750LI的前面有一个泄漏

Hello - there is an air bleed hose that runs across the top of the radiator (under a plastic cover) and into the expansion tank. There is a coolant level sensor, and a coolant transfer hose (expansion tank to the water pump) that could be leaking onto the undertray. Any of these connections can cause leaks where you describe - but, my money is on the air bleed hose - it is terribly easy to cut when replacing the expansion tank. I recommend a冷却液泄漏检查performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, confirm this diagnosis, and give you an accurate assessment of damage and cost estimate for repairs.