I had a shop evac / test / recharge my ac system. It held vacuum pretty well for the time being but I all leaked out over a week lol. Has anyone have any good experiences with this a can of stopleak? I dumped a 3oz bottle in with red dye then recharged the system with a subzero r13 can to full yesterday, awaiting a weeks time for the results.

One other question for you guys who actually have working AC systems with no problems. When you turn your ac off and park, do you hear the evaporator in your dash making a strange hissing noise for about 5 seconds? Lol it sounds very odd but maybe that is how these old cars sound. I'm not sure this is actually the first time AC as EVER worked in 10 years, I never cared to troubleshoot it or spend money on it. I know the sound must be the pressure stabilizing from the high pressure side to the low. Maybe that is just the nature of the system as refrigerant passes through the orfice tube. I don't believe it really keeps the pressure on the high side when you shut off the ac. lol anyway in short with the second question, do you get that weird spraying sound when you shut off the ac? Its not really a subtle sound nor is it very loud. Its certainly noticeable though. It does seem to loud to be an actual leak but who knows.

 

Did you get any good answers to your hissing problem? I've never used that stop leak stuff. I fixed my leaks by replacing the components of the ac. I have a 92 firebird and I didn't have any hissing sounds for two years. Now, the ac is less cold and that hissing sound is really loud for about 5 seconds after I turn the ac off.