Hello- I am the original owner 1988 classic. My ac is now blowing warm air.My sight glass has bubbles. I did recharge it about 10 yrs ago with Freon-worked fine,until now.I bought the Inter dynamics AK-12 arctic freeze kit which is hand held and you screw in the can and press the trigger and 1 of 4 bars will tell you if you have to add more refrigerant or you have too much etc.I also bought at pep boys the values that will attach to the old style high and low pressure schrader values. I also bought Enviro-safe r134a-r12 replacement+dye 12a.I tried to add the can but it still blows warm air, the bubbles are gone now,the low pressure line is not cold, high pressure line hot. When adding can it does not seem much refrigerant is being sucked in and the AK-12 bar says I have to add more. I kept on doing this with same results. What am I doing wrong- Help!!! I do have a question- On top of the receiver/dryer where there is the sight glass there is another valve what is it for-somebody told me to add the refrigerant there??? Thanks all of your help.