All AC automobile compressors now used on engine
driven pleasure boat
refrigeration require occasional rotation for shaft seal
to retain oil
. The York compressor was one of the first generations of auto compressors and used a rubber V seal and relied on the pulley clutch
bearing to keep shaft sealed centered. The next generation of AC compressors all use a carbon spring loaded seal and a floating drive shaft.
sfnc is correct that systems out of service
any length of time can lose refrigerant through a dry seal. If the York clutch pulley bearing has lost
its lubricant any wear will cause refrigerant loss, if so in addition to presents of oil on compressor face there will be traces of red metal colored oxide if clutch bearing needs to be replaced.
The normal corrective action for shaft seal leakage is add refrigerant as loss of oil from shaft seal is very small. Your compressor contains 12 to 13 ounces of oil so unless there is a lot of oil every where do not add oil.