Td5 oil cooler O ring size

[Chanoo]

Hello folks,
Can someone confirm for me please, the O rings for the td5 oil cooler are 25mm x 3.5mm and nitrile.
Second question, apart from the oil cooler unit corroding and leaking, what else fails with the oil cooler that would allow oil into the coolant. Is the the O rings on the cooler or another gasket/rings some where?
Thanks

[Patrick110td5]

32mm measured external to external.
Yes I think your correct,
https://uploads.tapatalk-cdn.com/20200904/7acbf19ff0f256e5cd30e047ee732545.jpg

[Patrick110td5]

The oil cooler can rust, and fail. I think it may have some sort of coating so be careful when handling.