In the late 1990s car manufacturers switched the construction material in their fan belts from neoprene to a synthetic rubber called EPDM (Ethylene Propylene Diene Monomer). Besides requiring the use of another automotive acronym, what the change accomplished was to produce a component that had a longer life.
With the increased longevity of the EPDM belt came the sticky question--when do these belts need to be replaced? Previously, the appearance of the belt was a giveaway. The belt would appear cracked or have chunks missing and there was an industry standard that said if the belt had three cracks in any three inch section it should be replaced. This straightforward approach was lost with the advent of the EPDM belt.
These belts make remaining life very difficult to predict because they lose material very gradually, similar to a tire. Although it is suggested that belts need to be inspected after 50,000 miles, it is hard to gauge with the naked eye how much of the ribbed section of a serpentine belt has disintegrated.
It is estimated that just a 5 percent loss of material can affect the performance of the belt. A belt slippage rate of 10 percent can make a crucial difference in the drive-ability of a vehicle as the power is transferred from one component to another via the belt. Remember, the belts commonly are essential to the cooling, steering, charging and air conditioning systems.
As the ribs wear down they sort of bottom out onto the pulleys which reduces the efficiency of the component it drives. The reduction of material also makes it difficult for the belt to cope with all sorts of contaminants the belt has to contend with in a highway environment.
The Gates name is to the rubber under the hood of a car what the Goodyear name is to the rubber that meets the road. The family invented the V-Belt in the early days of the automobile. It’s marketing technique of sending an employee on the road with suspect belts and hoses in the hope that an observant gas station attendant would discover them while raising the hood was renown in the days of full service gas.
The company became part of a British engineering group in 1996 but the Gates name remains as a dominant force in automotive rubber products. At any rate the company is now offering, free of charge, to professionals as well as do-it-yourselfers a belt wear gauge. They suggest using the gauge reading as one component in your decision to replace belts.The other factors would be vehicle mileage and the condition of the other components like the pulleys and tensioners.
Follow the link below to sign up for the gauge.