Does anyone top off R12 A/C anymore?

[ZackN920]

I'm just curious. My system still uses R12, still works good, and cools pretty good. I think I could use a top off though. Who knows how long it's been since the last time it was ever done.

Like I said, it cools well but on a highly humid 95* day, it seemed (to me) like it was lagging when we were out on the highway. Had to keep it at max A/C to be comfortable.


I honestly have no interest in converting to R134. I've read that its not as efficient as the older stuff, unless I were to also have a larger evaporator? condenser? installed. (If that's the case, I may already have the best 134 could do-performance wise) I've also read that it runs at a higher psi in the system and is more susceptible to leaking out. It runs good on the old stuff, and doesn't appear to be leaking anywhere out of the norm.

Unfortunately for me (a DIY'r that does EVERYTHING), its illegal to handle unless I have a license. Even for the NOS can's of the stuff that was MEANT for the consumer to put in their own vehicle. So, what's my options besides doing nothing, and waiting for the a/c to become inefficient to the point that I just have it swapped?

[FSJunkie]

These systems don't really deteriorate in cooling capacity as they get low on charge. They work perfectly and keep working perfectly until one day they hardly work at all. That is the day they are low on charge. It is a pretty abrupt transition. They don't have much of a "low on charge and still cooling, but not cooling very well" stage. These systems are apretty overtaxed as it is to cool the large interior of these Jeeps, especially without dark window tint. On days over 90 degrees, it is just about all they can do to keep the front seat comfortable. I would not say that your system isn't performing below normal, or much below normal anyway. High humidity makes the system work harder too since condensing the moisture in the air produces more heat for the system to carry away.

The proof is in the sight glass. The high pressure line leading from the receiver/dryer to the expansion valve will have a sight glass in it. So long as there are no bubbles in that glass while the compressor is running, system charge is good. Bubbles indicate low charge or air in the system.

If your system only leaks one can of R12 per year, I'd say keep getting cans of R12 to top it off. My philosophy is that any system which leaks more than two cans a year gets converted to R134a because of the expense of refilling constantly with R12. These old systems are prone to leaking anyway, so for me that means most of them get converted and I just figure on topping them off once or twice a year.

R134a does not perform any worse than R12 in these systems. They use an expansion valve to control their cooling capacity. The expansion valve regulates the amount of refrigerant flow into the evaporator to maintain the evaporator outlet temperature at a preset point. More flow = colder evaporator. R134s is slightly less efficient than R12, which means the expansion valve will simply open up a little wider to flow more refrigerant to achieve the same evaporator temperature. It self-adjusts.

[Mr Carts]

Anyone use this stuff?

https://www.ebay.com/itm/R134a-R12-Alternate-A-C-Enviro-Safe-Industrial-Refrigerant-SUPER-COLD/152046918525?rt=nc&_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D2%26asc%3D52475%26meid%3D4329bb84a27c495a9dd5b12e9acc7d4d%26pid%3D100005%26rk%3D3%26rkt%3D12%26sd%3D401340383184%26itm%3D152046918525&_trksid=p2047675.c100005.m1851

[ProTouring442]

Anyone use this stuff?

https://www.ebay.com/itm/R134a-R12-A....c100005.m1851

It is not an approved replacement (in the US), and is illegal to use in a mobile a/c here. Also, if you were to use it, you cannot have a shop evacuate the refrigerant as it will contaminate their equipment (and you could be liable for that). I'm not saying "don't use it." I'm only saying what the law is.

[440sixpack]

If a can or 2 of R12 gets you by each year don't worry about it. if it takes more than that maybe it's time to fix the leak and recharge it with R12. not R134a.

[babywag]

I'm just curious. My system still uses R12, still works good, and cools pretty good. I think I could use a top off though. Who knows how long it's been since the last time it was ever done.

Like I said, it cools well but on a highly humid 95* day, it seemed (to me) like it was lagging when we were out on the highway. Had to keep it at max A/C to be comfortable.


I honestly have no interest in converting to R134. I've read that its not as efficient as the older stuff, unless I were to also have a larger evaporator? condenser? installed. (If that's the case, I may already have the best 134 could do-performance wise) I've also read that it runs at a higher psi in the system and is more susceptible to leaking out. It runs good on the old stuff, and doesn't appear to be leaking anywhere out of the norm.

Unfortunately for me (a DIY'r that does EVERYTHING), its illegal to handle unless I have a license. Even for the NOS can's of the stuff that was MEANT for the consumer to put in their own vehicle. So, what's my options besides doing nothing, and waiting for the a/c to become inefficient to the point that I just have it swapped?

You can take an online test to get "certified" for r12/AC work, takes all of ~15 minutes.

https://www.macsw.org/web/MACS/Certification/Online_Test.aspx

Buy some small cans of r12 on eBay or local CL...if can be found easily.
Toss a can in there, and be done with it. Stay away from the combo cans w/ leak crap in there.
My '90 takes a can every year or so to regain full cooling capacity. You can tell when it needs it.

You can buy a decent gauge/hose set online. Or just buy/use a can tap.

[RoadRacer_Al]

I know you said "DIY" but I just had the dealer-installed underdash unit on my 67 serviced with a new gasket and a full load of R12. Not every AC shop has R12, so it is worth the call.

The downside is that R12 isn't being made any more, and it's almost 10x the price of R134.

I thought the cost of the service wasn't exorbitant, especially since, to me, AC and Automatic Transmissions are just this side of magic.

[Mikel]

As mentioned by others, R12 can still be found and has come down in price quite a bit in recent years, as demand has dropped.

But for an unmodified R12, many people have had good luck with R152A (keyboard duster). Dirt cheap, works much better than R134A in R12 systems, with no modifications required.

[ZackN920]

These systems don't really deteriorate in cooling capacity as they get low on charge. They work perfectly and keep working perfectly until one day they hardly work at all. That is the day they are low on charge. It is a pretty abrupt transition. They don't have much of a "low on charge and still cooling, but not cooling very well" stage. These systems are pretty overtaxed as it is to cool the large interior of these Jeeps, especially without dark window tint. On days over 90 degrees, it is just about all they can do to keep the front seat comfortable. I would not say that your system isn't performing below normal, or much below normal anyway. High humidity makes the system work harder too since condensing the moisture in the air produces more heat for the system to carry away.

The proof is in the sight glass. The high pressure line leading from the receiver/dryer to the expansion valve will have a sight glass in it. So long as there are no bubbles in that glass while the compressor is running, system charge is good. Bubbles indicate low charge or air in the system.

If your system only leaks one can of R12 per year, I'd say keep getting cans of R12 to top it off. My philosophy is that any system which leaks more than two cans a year gets converted to R134a because of the expense of refilling constantly with R12. These old systems are prone to leaking anyway, so for me that means most of them get converted and I just figure on topping them off once or twice a year.

R134a does not perform any worse than R12 in these systems. They use an expansion valve to control their cooling capacity. The expansion valve regulates the amount of refrigerant flow into the evaporator to maintain the evaporator outlet temperature at a preset point. More flow = colder evaporator. R134s is slightly less efficient than R12, which means the expansion valve will simply open up a little wider to flow more refrigerant to achieve the same evaporator temperature. It self-adjusts.

Really?, they don't deteriorate with the possibility of a lower charge HUH.


Sight glass: No bubbles while running BUT, after the compressor disengages, it does sort of drain back, and then look completely empty. Then when the compressor kicks back on, after a sec or 2, bubbles whoosh by and disappears into what looks like a good flow of liquid.


I can't say that I have any "unnatural" leaks in the system. No spots that look suspicious, no, Freon smell to it(unlike my Dakota when it's AC died a number of years ago). I would think it'd be just years of normal use and operation. I have read that all systems leak a little right at the compressor itself. Makes sense to me. Seals wont necessarily be perfect where a spinning shaft is.


My problem is that *I cannot buy can's (even the old diy cans autoparts stores sold) without that "magic" license. I also have no equipment at the moment. This is also the first time in 3 summers that I've thought the system seems … less efficient or effective.


Interesting info on the R134.

Thanks for all the info man.

Anyone use this stuff?

https://www.ebay.com/itm/R134a-R12-A....c100005.m1851

I think that and it's counter parts are a bad idea. Most of the ones that ive read about (that say are a direct replacement for R12) have in the ingredients: PROPAIN or some other highly flammable material/gasses.
I also noticed that they say that they cannot be mixed (added) to a R12 system with R12 in it.

Ive read some bad stories about junk like that and really don't want nothing to do with it.

If a can or 2 of R12 gets you by each year don't worry about it. if it takes more than that maybe it's time to fix the leak and recharge it with R12. not R134a.

Yea, that's no big deal but im trying to figure out how to get some R12 put in, or even if the system could be checked to see if it needs a little charge.
This is the first summer (3rd that ive owned the jeep) that it just don't seem as cold as it should be to me.

You can take an online test to get "certified" for r12/AC work, takes all of ~15 minutes.

https://www.macsw.org/web/MACS/Certification/Online_Test.aspx

Buy some small cans of r12 on eBay or local CL...if can be found easily.
Toss a can in there, and be done with it. Stay away from the combo cans w/ leak crap in there.
My '90 takes a can every year or so to regain full cooling capacity. You can tell when it needs it.

You can buy a decent gauge/hose set online. Or just buy/use a can tap.

Your ting me Certified in just a 15 minute test. Its available to the public?! I figured i'd have to be working some HVAC or actual "mechanic's" job to get a cert to play with refrigerant.

I know you said "DIY" but I just had the dealer-installed underdash unit on my 67 serviced with a new gasket and a full load of R12. Not every AC shop has R12, so it is worth the call.

The downside is that R12 isn't being made any more, and it's almost 10x the price of R134.

I thought the cost of the service wasn't exorbitant, especially since, to me, AC and Automatic Transmissions are just this side of magic.

Really?, so some shops still actually use the stuff. I'll have to check them out, maybe find out prices and stuff. Heck, i just figured in this day and age that any shop would want to just immediately swap it over (and make more cash)

It's still made, just not in the US. anymore.

Not magic, just stuff we don't necessarily know....yet.

As mentioned by others, R12 can still be found and has come down in price quite a bit in recent years, as demand has dropped.

But for an unmodified R12, many people have had good luck with R152A (keyboard duster). Dirt cheap, works much better than R134A in R12 systems, with no modifications required.

I'll have to look that R152A stuff up. Not looking for something that cant be added to the R12 that's in the system, so if the system would need a vacuum, that stuff is out of the question. Especially so, if it's another of those extremely flammable options.

[Mr Carts]

I went ahead and got the 5 can kit for my 77 C20 Chevy.

The A/C just blew hot air but still had pressure in the line.

The stuff works GREAT!! It took 3 cans to refill the system.

With the outside temp at 112 degrees, the air coming out of the vent is 48 degrees.

Driving down the road it was actully a bit cold and had to turn the A/C down from high speed on the fan.

[babywag]

I went ahead and got the 5 can kit for my 77 C20 Chevy.

The A/C just blew hot air but still had pressure in the line.

The stuff works GREAT!! It took 3 cans to refill the system.

With the outside temp at 112 degrees, the air coming out of the vent is 48 degrees.

Driving down the road it was actully a bit cold and had to turn the A/C down from high speed on the fan.

You realize that stuff is basically propane, and technically illegal?

[Mr Carts]

I buy my Propane and Propane accessories from Hank over at Strickland Propane


The stuff works great my A/C is ICE cold even in 110 plus heat.

[ZackN920]

yea, propane does well...but...It also tends to FIREBALL in a crash. It'll look like a movie explosion! Don't crash, be safe. Also don't smoke in the truck.





Ok, I just looked that stuff up online. I found that it is flammable, but no positive source that it's propane. The company claims its less flammable than raw gasoline or starting fluid. I also saw that it should NOT be mixed with other refrigerants.>mainly because its illegal to mix refrigerants. The stuff may actually mix and not be a problem, but I sure as hell aint ginnie piggin it.

Good luck with it Mr. Carts. You sure got some cold A/C now!

[babywag]

last small cans of r12 I bought 3 off CL and was only $60.
All you have to do is setup a search, emails new postings.
Call/email buy ‘em and done.

I have a 30lb of r12 now, but I still see small cans 4 sale frequently on CL.

Edit:
Buy it during fall/winter it’s cheap, spring and especially summer price tends to go way up.

[FSJunkie]

Really?, they don't deteriorate with the possibility of a lower charge HUH.

Sight glass: No bubbles while running BUT, after the compressor disengages, it does sort of drain back, and then look completely empty. Then when the compressor kicks back on, after a sec or 2, bubbles whoosh by and disappears into what looks like a good flow of liquid.

Yes, for the most part they either cool at full capacity or they don;t cool at all...for the most part. There is a small transistion where they will cool a little but poorly if they are low on charge, but it is a razor's edge. If you were to run a fully charged system and bleed off the charge as it was running, you'd find it would cool properly, have a brief moment where it cools poorly, then go to basically not cooling at all.


No bubbles while running means your system is fully charged and adding any more charge will do no good. They are normal to drain back the liquid from the sight glass when thecompressor cycles off and to bubble for a few seconds after the compressor switches on. Even while running steady there may be a bubble or two here and there in the glass and that is normal too. When the glass is totally filled with white froth is when they are low.


Your system is most likely completely fine right now. The A/C does not work extremely well in these Jeeps anyway because of the huge interior and large amount of glass.