So I have decided to give myself some cold air in my 72 Cutlass. I knew I had a noisy compressor so I replaced the compressor, all new lines, drier/accumulator, and expansion valve. Flushed out the condenser and evaporator. Was able to find some R12 so I picked those up instead of changing to R134. Vacuumed the system and it is holding excellent pressure with no leaks at all. Went to charge today and unfortunately the side entry can tap that I bought leaked externally. Messed around with the can and tapper and got the external leak to stop however I could not get the refrigerant to get to the manifold/gauge. Looking for advice as to if we think the tapper was the problem or could there be another problem. I definitely wouldn't want to waste another can of R12! Also, if anyone has any recommendations on a good can tapper for R12 cans. Thanks!

 

If there is a hole in the can and refrigerant does not reach the manifold I'd say it is the tapper. Does it have a Schrader valve? I have only used a tapper that latches onto and then pierces the top. Since R12 is getting $$$ and scarce the system could be leak tested with nitrogen vs risking losing/leaking the R12.

Good luck!!!

 

Sugar Bear, so unfortunately the tapper did pierce the side however never did reach the manifold. It does have a schrader valve. I ordered a top can tapper and will try that instead. No leaks in the system as it held vacuum over night. Just for some odd reason never made it to the manifold.

 

There are r-12 taps on Amazon for under $15. The cheap vacuum/manifold I bought has -134 fittings on the gauges but a -12 tap. I dunno who that made sense to. Local stores may have one also.
I replaced my A6 with the new S6 this year and did -134 and it works quite well in Houston.
50 degrees from the center vent in the driveway at 105F/60%+ humidity. This is on a ‘77, compressor, accumulator and orifice tube only after it held 25” for a week

 

The vacuum boils out the moisture in the system. The fact that it held vacuum is a good sign but it isn't a pressure test. The probability is that you'll be good, just putting the info out there.

Good luck and ice cold AC.