Hi all,

I have a moderate leak in my original R12 A/C (1978). It needs to be juiced up every year to cool. This year, again, it's only cooling just a bit. I exhausted the last can of my R12 hoard a couple of years ago, and last year's professional topping-off set me back $150. I think it's time to lose the R12, fix the leak, and recharge with Freeze-12.

I see in the FSM that the system takes 1.5 - 2 lb of freon, fully charged. I believe my topping off amounted to about a pound of freon, so would this imply that I have about 1/2 to 1 lb of freon in the system? Would that amount of freon give me a marginal cooling?

Then what to do with the R12? It's illegal to vent it. Will service centers reclaim my R12, and if so, would they actually want to charge me to take this precious substance from me?

I understand Freeze-12 is compatible with the mineral oil used to lubricate an R12 system, but it not compatible with the R12. Thus my plan is to evacuate and recharge with the Freeze-12. With this in mind, how do I determine how much oil is in the system and how much oil to add, if any?

Also, is there anything else I need to change out, other than the freon?

Thanks for any advice!

Sarah

..... and..... no sooner than I posted this and gone out to the garage to look in the FSM again, I FOUND 4 MORE LB OF R12!! Soooo... never mind. I swear, guys, I had spent the past few hours looking for any remaining cans.

I'd still like to see answers to very good questions.

My 77 has a slow leak. I put in freeze 12 last year, by itself and then later put in some freeze 12 stop leak. Once again this year it is low, but still cools somewhat, so I have no idea how much I have lost. When L28 goes and the turbo motor goes in I am going to replace all the o rings and lines in the engine bay and also paint the engine bay. If that does not fix it, I suppose it is behind the dash.

Fastwoman if i had 4lb of r-12 around i would tear the system down and find that leak, then fix it permanently. If its fixed correctly that R12 could last another 10 years vs 2 years of refilling a leaky system.

Kurby, that's probably a better idea.

Here's the thing: No sooner did I announce that I found 4 lb of R12 than my R12 can tap broke. :tapemouth:mad::tapemouth I can't understand how it happened. It's made from the very finest Taiwanese pot metal! Fortunately there were no R12 casualties. That said, my precious R12 is now worth about what Freeze 12 costs -- about $20 a can on ebay.

Anyway, there are can taps on Ebay, so I guess I'll be ordering one. I had so hoped to have cold air today. Ah well...

3-diameter can side tap, $25 shipped, eBay. Thank gawd.

I'll be taking your advice, Kurby. It only makes sense to find the leak before committing more R12.

I still wonder how to determine how much oil I have in my system without pulling the compressor and draining it. Is that the only way?

Edited April 16, 201213 yr by FastWoman

I have about 12 1lb cans on hand. Didn't know R12 was that high.

FastWoman - Here is what I would do. I would get a little Florescent AC Dye and get that into your system, then let run for a bit to circulate the dye. Hit everything with a LED Blacklight Lamp to expose any leaks. There are little LED Blacklight lamps avail at the autoparts store (good to have in the toolbox). With the cost of R12 Refrigerant, really all refrigerant - AND your time, it makes sense to identify where the leak is prior to dumping more R12 and $$$ into the effort. Check the Condenser, Compressor(behind clutch), and Evaporator, with the dye it will be very obvious!

I believe that it would be a good time to start lining up modern replacement components.

Sounds like a plan, Andrew. Do you think a few trips around town would be enough for the dye to reveal the leak(s), or would I have to leave it in there for much longer than that?

A few trips around the block might actually be too much. The dye works pretty quickly so as long as the compressor is engaged you should be looking for the leak.

That fast?! Wow. OK, Thanks! I'll definitely get some of the stuff.