Hi electrototal, I don't see the problem, unless the Compressor Belt may be skating that revolution a bit. Adjust its tension or change it, if necessary. Luck. S @ lu2 friovega63. Hello but why not give the full version of the matter at once, I wonder, and why events are ignored, when a question is asked or at least the full experience is not provided, in order to offer a better answer. If you comment on the latter before, I could have added, a possible obstruction, in the orifice of the expansion element, be it a thermostatic expansion valve, or a pipe or capillary tube. In addition to something like this, it can be happened, inside the dryer filter, by saturation of the compound that retains the humidity and the possible decomposition of the same, obstructing the inner maya of said filter. Also when not, a good vacuum procedure is carried out after a breakdown, non-condensable gases, which are visible through the pressure gauge, that urinate the fluctuation of the flow of liquid refrigerant in the final zone can remain inside the air conditioning system. of the condenser, creating a kind of turbulence, when it is not possible to mix, the air trapped inside the system, with the refrigerant itself and neither can the air, get to change its state equally in that area and without being able to pass, from gas or steam to liquid, as can the refrigerant gas it uses. In all cases of partial obstruction, the manometer needles, are in the area that are connected, either in the high pressure or the low one, these would always do the same fluctuation, with the increase and decrease of the pressures, before A similar situation. The reason for the discharges by the safety valve, may be due to the fact that you add more refrigerant to the system, believing in a possible loss of it, by failure, when in fact it was an obstruction, reason why it did not increase the low pressure and yes, it came to fire, the high pressure, justifiably activating the high pressure safety valve. Luck. S @ lu2 friovega63.