The main reason why the water could be leaking from around the packing gland is the nylon washer located in the packing gland, or if the rubber inside is bad. If the washer is cracked, or damaged it will allow the water to pass through. This will lead to the water leaking from around the packing gland. This problem can be fixed by replacing the complete Arrowhead Brass stem. In order to replace the stem you would either need to know the wall thickness, or the overall length of the stem with the check assembly pressed all the way in.
See below for help finding the correct stem
Choosing a selection results in a full page refresh.