What is the value of R12 refrigerant?

[charlier]

2 hours ago, Lotus BIll said:

Because my car is a Lotus Esprit Turbo SE.  It's an easier said than done thing when it comes to an Esprit.  I'd be looking at thousands in parts, plus around 15 to 25 hours of labor to properly convert R-134 as ALL (and I literally mean all of it) of the A/C system needs to be pulled out and replaced.  Just easier to go with R12 and get the proper cooling I desire.  

 

It may be possible that the design of the system in the Lotus might entail replacing more parts. That is not true for other vehicles in my experience.

 

An automotive engineer I know that was involved in the the models of VWs I own once told me the following about converting from R12 to R134a.

Basically if the AC system is open (ie all refrigerant has leaked out) you MUST replace the receiver/dryer component of the system. For conversion you also must replace the fittings since the R12 fittings are not compatible with R134a which uses different fittings. Then you also have to find the source of the leak and fix that.

He also cautioned me that the amount of refrigerant used is different when it comes ti R12 versus R134a. In my case the car had been hit by a deer and the AC system was compromised and repaired.

 

One VERY interesting thing he told me was that some AC compressors used by VW did not play well with R134a (ie a high failure rate after converting).

He believed that there was something about the design or engineering of those compressors that caused the high compressor failure rate when using R134a.

 

The VW I converted over to R134a has worked well. I once did a side by side test of two of my VWs (same models, same AC compressors, 2 model years apart). One was running R12 the other R134a. The VW running the R134a actually ran 2 degrees cooler (34 vs 36 degrees) than the one running R12. Given the age of the R12 charge that was not a big surprise. That did however dispel the idea that R134a did not cool nearly as well as R12 at least in these VWs.

 

The R134a conversion is still running fairly well going on 22 years now. The system has a slow leak so about every other summer I have to recharge the system.

Given how cheap R134a is, I can live with it versus trying to fix it.

[Frank DuVal]

OK, for 90% of the R-12 systems still out there, an R134a conversion is going to work OK. Maybe not the coldest, but OK. This includes the ones where the compressor needs to be removed to evacuate all the mineral oil, orifices need to be changed, TXVs  and suction valves need to be adjusted (which requires removal from the system). So even in this 90% are ones that are not easy just drop in compatible.

 

For the other 10%, it is only R-12 or start replacing parts that are not compatible. Condensers are #1 on the incompatibility list, as they just do not shed the heat needed to run R134a. Then there are the compressors that cannot use R134 due to internal design. Others are systems that were marginal in original design, early Caravans fit this description. Corvairs can be made to use R134a, but I find it much simpler just to run R-12 and get maximum designed cooling.😉

 

If a converted system only cools well at night, I consider that a failed conversion!😨

 

R134a may have a lower temperaure for a given pressure below 70°F, but from there up it is much higher. This is why the condenser side of the equation is so important. If the condenser can not shed the heat, the cold side isn't!

 

Like in a Corvair, to get best results with R 134a , you need to add condenser fans. Well, there goes the AACA  maximum points...🤔

[Robert G. Smits]

Some older Mercedes do not cool well in hot climates with 134 as the discharge temp is warmer with r134 than with r12.  This can be rectified by switching to a larger condenser and/or a more efficient compressor  Ebay has multiple listings for r12 so I question if it is illegal to buy it.  I listed some for sale on the parts forum a few days ago as I recently  converted my last car to r134.

[mcdarrunt]

The last car we used R12 on was a 1930 Plymouth where with no grill so a condenser would look super ugly. Used an under car small condenser with an attached fan. No way 134A would work with that small of condenser but R12 cools a 4dr sedan just fine. Off topic but I have (2) R12 recovery machines with one jug between the two. $200 takes them both but they are heavy so shipping would be pricey.

[Lotus BIll]

18 hours ago, mcdarrunt said:

The last car we used R12 on was a 1930 Plymouth where with no grill so a condenser would look super ugly. Used an under car small condenser with an attached fan. No way 134A would work with that small of condenser but R12 cools a 4dr sedan just fine. Off topic but I have (2) R12 recovery machines with one jug between the two. $200 takes them both but they are heavy so shipping would be pricey.

Where are you located?  Just wondering?

[mcdarrunt]

About 50 miles north of Dallas, TX

[Lotus BIll]

Well that's too far for a car trip even if Pappasitos is one of my favorite restaurants.

[Ben Bruce aka First Born]

4 hours ago, Lotus BIll said:

Well that's too far for a car trip even if Pappasitos is one of my favorite restaurants.

 

 CAN'T BE MORE THAN THREE DAYS FROM ANYWHERE.

 

  Ben

[Jim Keef]

On 9/21/2016 at 9:04 PM, John_S_in_Penna said:

How many pounds of R12 are required to

charge a system?  The air conditioning

in my R12 cars hasn't been operational

for many years.

I am a certified licensed HVAC technician and a auto A/C licensed technician for more than 25 years. To answer your question, it depends on the auto say you had a all car it should take no more than 16 to 48 oz. But a large SUV or a van they usually have 2 units one for the front and one in the back. Now they could take as much as 4,5,6, pound's or more. Also there is a low valocity oil mixed in with the freon most cars take about 8 to 10 oz so if you loose all or some of your freon you need to put some oil back in also , and one more thing, you said the A/C units in these cars has not worked in some time, well you will probably have a 50 50 chance of the A/C units that will blow out the compressor seal's and all the o rings cracked and dryer out because like I said there is oil in the system with the freon and if your A/C units have not been used in a while to keep all the rubber that includes the rubber hose line it will dry out and when you start charging a system with freon the pressure could crack open the seal's in compressor, o rings and rubber hose line will leak out all your freon. And if that happens to the seal's in compressor there is nothing you can do except kiss it goodbye. A/C system,s must run from time to time to keep the system lubricated

 

[Jim Keef]

On 9/21/2016 at 9:04 PM, John_S_in_Penna said:

How many pounds of R12 are required to

charge a system?  The air conditioning

in my R12 cars hasn't been operational

for many years.

I am a certified licensed HVAC technician and a auto A/C licensed technician for more than 25 years. To answer your question, it depends on the auto say you had a all car it should take no more than 16 to 48 oz. But a large SUV or a van they usually have 2 units one for the front and one in the back. Now they could take as much as 4,5,6, pound's or more. Also there is a low valocity oil mixed in with the freon most cars take about 8 to 10 oz so if you loose all or some of your freon you need to put some oil back in also , and one more thing, you said the A/C units in these cars has not worked in some time, well you will probably have a 50 50 chance of the A/C units that will blow out the compressor seal's and all the o rings cracked and dryer out because like I said there is oil in the system with the freon and if your A/C units have not been used in a while to keep all the rubber that includes the rubber hose line it will dry out and when you start charging a system with freon the pressure could crack open the seal's in compressor, o rings and rubber hose line will leak out all your freon. And if that happens to the seal's in compressor there is nothing you can do except kiss it goodbye. A/C system,s must run from time to time to keep the system lubricated

 

[Jim Keef]

I would suggest that you don't even think about charging the cars with R12 as high as it will cost you will probably be better off to test pressure the system with air pressure first and if it don't leak pull a good vacuum and change it to 134A. But then again you are still not out of the woods, because when you have the system fully charged, there will be more pressure on the system because freon will have more pressure than air so it still may blow out. What ever you decide to do, good luck.

 

[Frank DuVal]

Corvairs, even though they are small cars, use 5 (FIVE) pounds of R-12. Looong hoses!

 

I still fill them with R-12 if the systems are original. If updated with Sanden compressors after the A-6 dies, then it is R-134a time.

[vball2tennis]

I have a 66 Mustang with the original AC and it worked fine until this year when I tried to use it about a month or so ago.   No cold whatsoever coming out of the AC.   Is it most likely I need R12 or could it be something else?

[displayname]

On 9/13/2018 at 8:37 PM, Dave Henderson said:

Here's a buyer who advertises repeatedly in the "Wanted" column of the Washington Post;  www.refrigerantfinders.com   Phone  312 291 9169

I dealt with Refrigerant finders. I had a 30lb cyliner of DuPont Freon (R-12). Virgin cyliner, with original shrink wrap seal (that is barely still attached). Weighing in at 35.8lbs. 

They offered me $17/lb initially, then offered $6/lb. I am assuming that they are looking for people who have no idea what the value of R-12 for a classic car is.

[Dave39MD]

Frank, what is the problem with the A 6 compressor and r134? I was thinking of converting my old truck?

 

Dave

[Joe Block]

one problem with R134 is the older hose are foil lined and tents to leak out of a goods R12 hose.

[padgett]

OK I have one car still with R12 and that is the Judge, all of the rest have R134A.

 

The original problem with converting R12 to R134 was the oil. R12 mineral oil did not play well with R134 PAG/Ester. People failed to flush the system properly and the mineral oil residue caused problems.

 

Now my Judge is still R12 because I have some and needs about a can a decade. However when changing I replace the hoses, O'rings, gauge fittings ( high and low are only fitting that need to be changed), dryer, and oriface tube (white for 134). Pressure flush twice,  pull a high vacuum for at least a day, and then pour about 5 oz of the correct oil into the compressor. Finally charge until low side holds at 25-35 psi at 2,000 rpm with forced air. That's the short form but is no big.

 

Mostly work with GM & never had much trouble with A6s (have a sealed spare under the bench) but the DA-6 was very failure prone ("black screen of death") Harrison replaced with the HR-6 which is a good compressor.

 

Beyond that it is just a matter of being careful and clean.

 

ps reason I mentioned the sight glass going away in '73 was before that you just added Freon until the bubbles went clear and it had the correct amount. No gauges needed.

[Frank DuVal]

5 hours ago, Dave39MD said:

Frank, what is the problem with the A 6 compressor and r134?

 

Only what Padgett covered. I keep using R12 with the A-6 system. It is available on ebay still. Yes, if you change the oil then an A-6 will handle R134a just fine. I would rather buy R12 than buy a conversion kit for the refrigerant fittings. That's just me.  I still have an R 12 machine to evacuate and refill systems.😉

[Robert G. Smits]

I still have a supply of R12.  PM me if you need some.