Thank you for answering my question and it leads me again to ask (since I don't know about the subject) how can I know if my Refrigerator is losing coolant ..?
You should measure the pressure with a pressure gauge when the refrigerator is off, if you use R134a, the pressure should be around 40 psi, if it is below that value, it may be leaking, if it marks you 0 psi, there is no doubt that all the refrigerant is discharged, however, if you turn on the refrigerator, the pressure will be empty, in case of leakage, or partial obstruction in the filter drier and / or capillary tube, the most reliable way in case of If you press the pressure gauge while it is off it would be to take out what is left of the refrigerant, pressurize the system with nitrogen and leave it for a few hours
Here where I live they are all alive, I called a (technician) came with his Hilux (van) under the bottles I charge him and nothing else .. If he loses or does not lose if the filter serves or not, etc. etc. he told us on the phone that he would leave 1300 we called him when he came, he said 1800, then he wanted to charge me for labor, I don't know about refrigerators, but I'm not a fool ...