AC re-charge R-12

[Kelly454]

Ok this is for all you C-3 air conditioning experts. My 71 is low on R-12, I can see bubbles in the sight glass on the dryer. The car has set up for a number of years, and I am just now getting it out and driving it. I want to keep it a R-12 car. I just need a opinion on how many cans of R-12 I should purchase to re-charge the system. All you early C-3 AC experts fill free to chime in.
don’t want to buy any more than I would need due to the high price of R-12, and yes I am a cheapskate , well in this economy who’s not lol .:L

 

[LVMYVT76]

I think the system hold about 2 3/4 cans, so I would buy 2 or 3 and have some extra on hand. You may need to put new seals to keep from leaking what you are going to put in, or it could be a compressor seal leaking. You might want to check it out for leaks first.

 

[73shark]

If you have a partially used can left over after filling your system, store it in a freezer to lower the internal can pressure so it won't leak out as fast as it would at ambient temps.