I would not spend $$ to so-called 'service' compressor , be it at SC or outside aircond shop .
Having said that , before the compressor kong if ever it happens , the warning sign is that the cool air from aircond system is not running cold enough when compared against normal times .
By then and only then, I will visit an aircond shop outside for the sole purpose of topping up refrigerant gas AND some compressor oil simultaneously , with or without filter drier change depending on shop recommendation .
In other words, if aircond system is working fine I won't visit SC or outside for so-called compressor 'service' .
Btw, I roughly know how aircond compressor/evaporator/filter drier/condenser works .

This post has been edited by zeng: Jul 18 2020, 01:55 PM

That is normal for almost all cars, I suppose .