A/C refill - 134a alternatives

XJ
1

System converted to 134a, ten years or so ago, only the basics (134a ports, flush, vacuum, oil and refill) and worked worked quite satisfactorily since then.
Only drawback is that the non 134a compatible rubber hoses are always a bit oily from the escaping gas, and in the course of six years or so since the last refill, it’s now low on refrigerant.
So now, in 40°C summer, it’s time for a refill and I am considering the hydrofluorocarbon can alternatives that can be found on e-bay and the likes.
As far as I can understand, a major benefit would be that they have bigger molecules, thus the permutation through the hoses will hopefully stop.
Plus, it’s DIY, fast and inexpensive.

Questions is, are all these brands the same product, or are there major differences?
Any favorites?
Any drawbacks?

And, last but not least, is it possible that the compressor has lost also its oil?

Thank you.
Aristides

2

If this is the same type of product we have here in Sweden it is most likely just straight up propane/butane. Since the sale of r134a was limited to only those who have proper equipment and training, there has been an explosive increase of vendors who sell ‘AC replacement gas’.

I took a look at the page you pasted above but couldn’t find any safety data sheet - SDS, an EU vendor is required to present a SDS in a member language according to REACH (EU Legislation); so I would try to get an SDS to see what you are putting in the AC system at least to begin with.

A popular site in Sweden is Fylldinac.nu (fillyourac), their AC replacement product is 50% propane and 50% butane, see 3.1 in SDS (Swedish)

I understand the reason for the mix is to simulate the vapor pressures of r134a, propane has a much lower boiling point, therefore it will be alot colder in the system, but the system will experience much higher pressures if OEM quantity is added, easy solution - add less propane. Butane has a higher boiling point, and will therefore not cool well enough, but mixed with propane will bring down the operating pressure. If you could find LPG (gasol in Swedish) with a mix of the two you could just fill the system with that, but then going by system pressure not quantity, or pure propane and add less of it. If you feel uneasy adding propane to your AC don’t buy these hydrocarbon AC refills, since that is basically what they are.

I have found a type of cooling spray at a popular Swedish car parts company which I believe could be an alternative. From the SDS you can see that the content is 100% 1,3,3,3-Tetrafluoropropene, ie. HFO-1234ze(E), on a molecular lever very similar to 2,3,3,3-Tetrafluoropropene - HFO-1234yf, a refrigerant used in the AC system of many new cars.

This brochure gives a lot of interesting information, as does this article from KTH Royal institute of technology (english). The use of this gas would probably not solve the issue with evaporation of the refrigerant as I am unsure of the molecular size, however if you are servicing the system at home it might be a lot cheaper than servicing it at a shop which is the only place to go for r134a.

Keep in mind that to properly service the AC you will need to have a vacuum pump to pull a full vacuum on the system, after which the vacuum ‘draws in the refrigerant’ which you add until the system reaches full operating pressure while running. The refrigerant isn’t something that can really be topped off but has to be weighed, if using OEM refrigerant, or by monitoring the pressure until it reaches OEM operating pressure. Don’t forget to add a label or similar of the type of refrigerant used, if a shop were to empty the system of a wrong type of refrigerant it could break their machinery and ruin any refrigerant they might have stored in the machine prior; I have heard rumours of people having to pay mechanics hundreds or thousands of euros for broken machinery due to previous use of the wrong type of refrigerant.

If the compressor were to lose its oil I’d expect probably hear it by how it’s running, ie. grinding etc, or by it getting overly hot from the friction, maybe even blowing the thermal fuse. Seal kits and repair kits are readily available since the OEM compressor is just a GM part, or at least readily available here in Sweden. The compressor will need to be oiled when servicing the AC.

Hopefully I’ve answered some of your questions, I have been through this same debate myself since the AC on my -85 xj12 isn’t working, and I don’t really have the funds to take it in for a proper service.

Kind regards!
Rasmus

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Rasmus,

Thank you very much for your very detailed and informative answer.
I was a bit on a rush, it’s quite hot here now, and I have already ordered the Easyklima product…
I’ve sent them an email asking them for the SDS.

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I have 134 for about 10 years in it and still works.
Walter

5

After a lot of research I finally took the decision and refilled the A/C wit this Butane/Propane mix.
Filling it was very easy and the A/C is now blowing nice cold air.

External temperature 37°C
II°C at the vents
Low pressure: 50psi at idle
25psi at 3.000rpm.

I can see some occasional bubbles at the sight glass, so I know I haven’t overfilled it.

I had R134a in the system for many years and it was ok, but it never worked this good.
No ill effects so far.

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What lubricant did you use, and was this a commercially available mix?

EDIT: appears regular mineral oil works.

7

Very interesting article.

As I didn’t flush the system, I didn’t add any oil.
Before filing, when I opened the valve to get the air out of the filling hose, I could clearly see the presence of oil.
According to the products manual, and from what I’ve read, the Butane/Propane mix is compatible both with mineral and ester oils.
There are some kits that provide oil in a separate can.

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Nice to hear the AC’s working again!
Hopefully you’ll have less problems than before with evaporation, I’ll have to get an update when I go ahead and fix my AC, scheduled for next spring.

I doubt there will be any serious issues with changing the refrigerant, as long as you keep in mind that the system now runs on propane/butane.

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Hi Aristides! I hope you have better weather in France than we do in Stockholm, I’ve had the car on jackstands for some service for the past few weeks, all of which were lovely sunny fall days, but just as the repairs were finished it seems like the rest of the year will be rain and gray skies until I have to park the car over the winter, I digress!

I was just writing to check how the AC has been working, depending on whether I get my hands on any cheap r134a (from somewhere) I might just go with the propane/butane option; but I’m still undecided.

/Rasmus

10

Hi Rasmus,

Last time I used the A/C was the middle of August, still nice cold air, but still some penetration trough the hoses.
Since then the weather was not good, fall came very early this year, last week we even had frost in the morning…

Used the same mix to charge our 1990 190EMercedes, worked well also.

Best,
Aristides

11

Here in the US, R1234YF cost is about 10x the cost of R134a; it is also flammable. Fill fittings are different, and recovery equipment is not compatible. Also, EPA requires longer vacuum hold and requires the tech to state that there are no system leaks and held vacuum for the appropriate hold before it allows charge. There is also time stamps and vehicle ID fields documented.
At this time the EPA is not performing audits, but who knows in the future…will lead to alternatives if they stop R134a production.
I have never had anyone ask for my a/c certificate to buy R134a at Autozone or on Amazon. Autozone will even loan you a manifold set and vacuum pump for a deposit.