I have some questions about R-134 air conditioning systems. With the high temperatures of south Texas this summer, the low side pressure has been increased by about 5psi in the heat of the day on various vehicles. Is the increase in pressure caused by air in the system expanding and being pushed through the system by the compressor? This is resulting in air conditioning not being as cold because of the pressure build. If this is the case, what is the best way to bleed the air out of the system?