Hi Naza, everything indicates a picture perhaps of humidity, this does not always occur at the same temperature, so it can manifest itself at the moment, or even take days to reappear. Do a good sweep with nitrogen, if you have already used the R-141b, after all this it would be best to change all the oil in the compressor, but before loading the new oil and then obviously removing the old one, apply heat to remove a possible stagnant humidity at the bottom of the compressor, to apply such heat you can use a heat station, the heat must be discreet but with sufficient intensity to remove moisture, but at the same time that a lot of heat does not damage the glass insulation or glass, from the terminals or terminals of the compressor itself, because you would irreparably damage the housing. After the heat, put plugs on the discharge and suction pipes, connect a vacuum pump, by the service outlet provided and keep the pump running, until the compressor cools to room temperature, load the new oil and mount or reinstall in place, as soon as possible to the compressor, weld all the pipes, placing a new filter drier, yes or yes, make the entire system empty again and ready to load with refrigerant and fire the old moisture. Luck. S @ lu2 friovega63. Hi Naza, I do not know why from the beginning, you did not comment on this change of compressor, I want you to know that the difference between capacities is somewhat strong and the compensation of the capillary becomes essential, product of the passage of refrigerant through it employing a compressor with a greater cooling capacity, imposes a greater throttle, which when not corrected, the system literally speaks, a bottleneck, which first begins to hover, negative pressures and then as a dive or free fall, enters a vacuum, which can reach -28 or -30 inches of vacuum, causing the evaporator to first defrost as in a humidity box and finally it can end up damaging the compressor itself. To compensate for the capillary and correct with it the difference between powers, luckily it would only be enough to decrease the length of the capillary, cutting it up to about 60 centimeters, which would differ from each other both capacities, taking into account that these are between 1 / 5+ and 1/4 HP. Luckily it is only cut and not increase, because it would be more difficult. The complicated thing would be if in the way the capillary is installed, there are no ways to eliminate that amount of 60 centimeters in its total length would be 600 millimeters, because in that case it would have to be done, placing a new capillary with the same internal measure preferably and achieve compensation through the pressures that can be obtained in the high pressure gauge, once an appendix is placed at the end of the condenser, before the dryer filter, with the capillary previously welded, stretched along its entire length, without making the spiral to pick it up and with its tip or end opposite to the cut and free filter, to allow the air pressure generated by the compressor to escape, during the compensation process. S @ lu2