Does anyone know what size and shape washer an old McD frost-proof exterior faucet might take? In attempting to replace old washers, they appeared to be 1/4″ flat, but one faucet continued to leak badly. I tried a 3/8″ beveled washer which I which I had to force into the “cup” and that fixed the leak. But the otherfaucets were all right with the flat washers. I’m thinking the bevel washer may have compensated for a damaged seat, but I want to make sure I have the right washer in the others so I don’t cause any damage. THANKS.