After my last ride (couple weeks ago), I parked the bike and the next day, found a puddle of liquid coolant under the bike.
Censored French swearing!! 😠
It took me a while to find where this is coming from, as it only leaks when the cooling system is hot and under pressure. After a rather tricky investigation, I ended up narrowing the upper part of the plumbing, with coolant spraying upwards on the air duct. I finally was able to spot a pinhole on top of the middle part of the 4 legged hose… So I decided to replace all the hoses by newer silicon ones. 35 years old rubber is asking for trouble if you intend to ride. After some research, I purchased from a UK based company :
https://racebikebitz.com/Ducati-851-Samco-Sport-Coolant-Hose-Kit
I went for the « classic matt black » option, which is the closest to OEM, more so than the « vintage classic » option, according to their very helpful salesman.

As these are made on order, there’s a 4 weeks delay. More to follow on this.