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Reservoir (expansion) tank leaking after dissasembly
Hello everyone! I bought a Mini Cooper S R56 a few months ago. So far I have been enjoying it a lot! It looks like the previous owners never changed the coolant, and the expansion tank was very dirty. I took out the expansion tank to clean it, but upon reconnecting it, it's leaking coolant before I even start the engine. I did make sure to hear a click sound when I connect the tank back to the connector hose. There are two parts in between the tank nozzle and hose, one is rubber and one is plastic. Are they both supposed to be inside the hose? If so, the rubber ring doesn't fit into the hose. Or maybe I'm just not inserting the tank nozzle deep enough into the hose? Has anyone had this problem? Sorry if this question seems a little stupid, it's my first time doing this kind of task. I am attaching some pictures for reference. Thank you in advance!
The plastic piece looks ok but it’s highly recommended that you replace the O-ring even if it looks good.
Does the o ring go in the hose or not? From what I saw it's too large to go inside of it, but maybe it just increased in diameter from the coolant? Also, do you know where to find the part number of it? I looked at parts catalogues, they don't show it in the expansion tank diagram or for the cooling system diagram. I'll have a stop at bmw today, hopefully they can help me out. Thank you for your reply.
Thank you so much! I guess it's a common failure. This is actually my first mini. I've had a volvo for a long time and I've never encountered these issues. I ended up ordering the full hose with the connector, as I couldn't find the connector on its own. Will update once installed.
Sorry for the delay! The part I ordered came with the o-ring inside, which was different to anything I saw at BMW when I went to ask for it. It's been 6 months and everything has been working amazing!
