'03 Camry has 42K miles. Mechanic says water pump and serp belt need replacing.

the fact that it is over 8 yeaqrs old, I would recommend it too. Roy

Toyota uses a seal in their water pumps that may seep coolant and leave a build up around the weep hole. This does NOT mean the pump is bad, unless you are having to add coolant to the system. If there is no noticeable coolant loss, the indications of leakage at the weep hole is fairly normal. If coolant is being loss, the pump will need replacement. With the belt, age is a factor as well as wear. At eight years, replacement would be normal.

If you are leaking coolant from the pump,Then yes replace it.It is unlikley that it is bad with that mileage.I would have to see it.Get a second opinion,And not from a chain store.