1995 Silverado --I've located a freon leak somewhere inside the cab, probably the evaporator coil. It leaks out in about 3 weeks. I know it's a nightmare to get it out to even check it

. Does anyone know of any leak stop stuff to put in the A/C that might work? Anyone have any idea of a $$$$ estimate to have it checked out or repaired? I have an electronic freon detector and it detects freon in the ducts after sitting all night and putting the probe in the duct and turning the fan on. 72,000 miles, no rust, almost showroom perfect, but I still hate to put a wad of money in it

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