My hoses *look* okay…
Most hoses fail from the inside out. Rubber hose deteriorates with age and exposure to heat. The hose material can become hard and brittle. Tiny cracks develop in the rubber which eventually cause the hose to split, blister or leak. Oil on the outside of coolant hose can also accelerate the breakdown of the hose material. Today’s bimetal cast iron/aluminum engines and aluminum radiators can create conditions that set up an electrical current in the coolant. The inside surface of the hose becomes a conductor, which causes the material to pit and weaken. Cracks and striations tend to form near the ends of the hose that eventually eat through from the inside out causing the hose to fail.
Hose Warning Signs
Your vehicle overheats, Your coolant light comes on, Your heater does not work, You smell antifreeze
If the rubber on hoses is susceptible to heat damage, then belts must be, too.
Correct – belts also deteriorate with heat and mileage. Every time a belt passes around a pulley, it bends and flexes. This produces heat in the belt which hardens the rubber over time. The wear process can be greatly accelerated if the belt is loose and slips. The additional friction between belt and pulley will make a belt run even hotter. After millions of such journeys around the pulleys, even the best drive belt begins to suffer the effects of age. The rubber begins to crack and fray, and the internal cords become weakened and brittle. If your belt breaks you will loose whatever functions powered by the belt like your water pump, alternator, power steering, air conditioning, etc…
Belt Warning Signs
Your battery or check engine light comes on, Your belts squeal when your turn on or drive your car, Your A/C won’t work