The general rule is that once a capacitor get 10% below it's rated Uf value, it needs to be replaced. I've seen capacitors that aren't leaking or bloated, and are 25% below their rated value, and they still seem to work fine; or are they working as they should? My question is: once a compressor or evaporator fan capacitor loses more than 10% of it rated UF output, is the fan motor running at a slower rpm? What is really happening to the motor when the capacitor isn't at it's full rated capacity?