2005 Prius with 132,000 miles. Dealer started telling me about 30,000 miles ago that the water pump is leaking and that the serpentine belt is cracked so both should be replaced. My father was a mechanic, so I grew up working on cars (in the 1940s - 1960s).
I don’t see any signs of water pump leakage. Neither have several places where I’ve taken it for oil change. (I’ve specifically asked them to look for signs of water pump leakage.)
I do see a little cracking in the serpentine belt, so I decided that it might be a good idea to have it replaced. I went to an independent repair shop (which was highly recommended by two friends.) to get an estimate. He gave me one ($82), but then said that he has never known of one actually breaking. He said that they are reinforced with fiberglass, so unlike the old days, they just don’t break. He said that if I see chunks missing, or hear the belt squealing, then it needs to be replaced. Does this sound reasonable?