How often should I replace my belts and hoses?

It used to be easy to spot aging in belts and hoses, but modern parts often show no outward signs of damage. A good rule of thumb is to replace your V-Belt every 30,000 miles, while your serpentine belt and timing belt should be replaced every 50,000, although these numbers vary depending on the make and model of your car. Hoses should typically be replaced every four years. Because of the cost and extent of the damage that can be caused from a broken belt or burst hose, it is good to have a mechanic regularly check these things and to err on the side of caution.