The hoses and belt have no specified time that they wear out. The best thing to do here is to let your qualified tech inspect the belt and tell you when it needs to be replaced. If you look at the belt and it appears to have cracks in it, it is time. As for the hoses, some last a long, long time. I have 1 customer with 150k on the same hoses. The most important thing with the cooling system is the coolant flushes be performed at least every 2 years.
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