my system was serviced with freeze 12,  would cool to about 49 degrees,
100+ outside,  with some bubbles still in site glass.  [as long as
comp clutch was hot wired] then valve stem on high side started leaking
and i lost all my refrigerant. [i replaced it]  i was told the oil
mixes with the gas and when you lose refrigerant you lose your oil.  so
now, my question is, how do i know how much oil i have left?  how do i
add more? what kind? [hopefully w/o taking off compressor]    thanks
gary