Many Dinos haven't been treated well when they were low budget Ferraris. Especially in warm countries some used them without adding antifreeze to the coolant cycle and thus also didn't give corrosion protection. Many water tubes have significant corrosion parts and are build close to the water so to say. As this isn't something to typically fix on the side of the road you may want to make sure to have proper replacement.
We have been offering stainless ones for many years and now also have them in aluminum.
Advantage stainless: the tubes practically are everlasting. Here in our shop
Advantage aluminum: of course, purists value the original material but also the weight of the aluminum pipes is 1/4th of the same stainless one even though we reduced the wall thickness of the stainless ones already.
Aluminum pipes here in our shop
