My AC will turn on fine, pump out cold air and then after about 8 minutes the Fan will shut off. It sounds as if the compressor is still running but not the fan. If I don't turn the unit off right quick enough it start making a hissing noise after a minute or two. I cleaned the coils very well and also replaced the capacitor and it still does the same thing. Any help?

If you've replaced the capacitor, the problem is likely with the fan motor.