Matias Weld the service valve to check its pressure? I understood that, sorry if I'm wrong, but if it is to see if it has gas or not, that is not done, because when placing the service valve by logic the refrigerant will come out, a pinch valve is placed and so, if you can see What is the pressure on the low side, I am one of those who do not like to waste time, well, short where the filter is and so I see if it has gas or not, if I see a little gas spark, then that team It brings a leak somewhere in the pipe or pipe, but if enough gas comes out, it is logical that the filter was clogged or in a given case, the compressor lost performance, in short, and after the compressor was disengaged, the test of compression or right there cover with a finger the output of the condenser and if it throws my finger because this means that the compressor still has very good compression, if you want a more precise data because a service valve is put on the high tube and the gauges are placed, etc, etc, but for what you say, it seems that that team lost the refrigerant due to leakage, regards