I tried charging a friends A/C with R-134a (which is what it uses). He had hot air blowing out, and I have charged my prior honda's and other vehicles this way, I have a reusable hose with a gauge. Anyway, everytime we hook the gauge up, and put some refrigerant in, it shoots all the way to 150 psi, I know it is illegal but he bled the air out until it was down to normal, but right after taking the gauge off and after bleeding the air out, about 15 mins later it was right back to being way overcharged. Does anyone know what the problem could be?