Roger Roger
I am le tired
Pratt logic: pressurize the oil tank so every little seep turns into a full on leak.Having spent most of my career in front of Pratts of one form or another, the only mystery is why they went with their oil quantity indication system....
IE, if it isn't any leaking on you, you should add some. Guess they carried it over from their recip days.
Richman
Garret logic: draw a vacuum on everything so unless there are gaping holes in the gear case you won't see any oil leakage.