Heat cycles as well as age come into play, it don’t ever see 12 years before it fails, it gets very brittle. Don’t you replace hoses without waiting for them to fail? It’s a guarantee that you couldn’t get the hose off without breaking this part. It’s so common that any Nissan dealer stocks these parts.really what is the purpose of this part? couldn't you just run the hose all the way and connect it to the firewall outlet? or is this in fact some sort of valve or something on the inside that only opens up once the coolant has heated up? i figure i'll get one whenever i do a coolant change or maybe the 2nd coolant change. i think the first one is recommended at 100k miles or 7 years whichever comes first. mine will be at 75k miles in 7 years....then after that it says do it every 5 years or 75k miles whichever comes first....so i figure in 12 years i'll be close to 125k miles and i'll swap it out then. i'll keep the stock one as a backup.