kbuskill
***CAUTION*** I do my own stunts!
My stockers have lasted 16 years, just saying. I doubt anyone can make any that last longer, but even so 10-15 years for plastic that has hot fluid flowing through is pretty damn good.
I am shocked and amazed that they have lasted that long. Not to jinx you but my guess is that you are on borrowed time.
I have replaced mine twice in the past 3-4 years. Not sure if they were original or not since I bought used.
Once I was pulling a motorcycle trailer up the side of a mountain, 2 lane road with no shoulder. One of the connectors broke clean off and dumped all the coolant out of the engine. I had to drive about 1/4-1/2 mile to get to a wide spot where I bypassed the heater core and filled the cooling system from melted ice in my cooler.
Then I replaced again within the past year because of it cracking and leaking.