My 2001 Ford Explorer is in great condition and only 73,000 miles. However AC quit working and the mechanic says its an easy fix IF I can find an original Schrader valve. Should cost less than $10.00. Apparently Ford changed the design a few years ago and the schrader valve that you buy in the parts store today will not fit the 2001 ac system. He said that the modification to make the new style schrader valve fit my old car will cost over $800.00! Any help or advise would be greatly appreciated. I'm attaching a picture of the original valves.