Charging or converting an R-12 system

[dorough]

I just bought a '93 2.3 Ranger. The AC system (so I'm told) holds pressure and the system just needs to be charged. It's the old R-12 system. Several (probably semi-stupid) questions: Is it still possible to get a charge with the old R-12? If so, how much $$? Or do I have the option of converting to R-134a at a reasonable price? Just wondering what my options are. Thanks in advance!

 

[exbass94]

It's possible to get an R-12 charge from a shop, but it is expensive. It's hard to buy yourself, since it's hard to find, and you technically need a 609 certification to buy/use it.

To convert to R134a, you need to discharge all the R-12 (disclaimer: it's illegal to vent it yourself), fix any leaks (ideally, you should change all the o-rings in the system. If some are too much of a PITA to get to, don't worry about it), change the accumulator, drain all the mineral oil from the compressor, add ester oil, vacuum the system down and check for leaks, and recharge with R134a.

 

[mp3deviant721]

It's possible to get an R-12 charge from a shop, but it is expensive. It's hard to buy yourself, since it's hard to find, and you technically need a 609 certification to buy/use it.

To convert to R134a, you need to discharge all the R-12 (disclaimer: it's illegal to vent it yourself), fix any leaks (ideally, you should change all the o-rings in the system. If some are too much of a PITA to get to, don't worry about it), change the accumulator, drain all the mineral oil from the compressor, add ester oil, vacuum the system down and check for leaks, and recharge with R134a.

What this guy said. I'd personally convert to R-134a as R-12 is getting harder to find and getting more expensive.

 

[4x4junkie]

I converted my '90 to R-134a almost 4 years ago and it's been working great. I did replace the compressor and used PAG oil (#46), though if your existing compressor is in good shape (and does not leak), this shouldn't be absolutely necessary.
I don't recall having any issues getting to and replacing all the o-rings in the system.

 

[aspevacek]

I personally would also look at swapping the hoses on the system if you are doing the swap. The head pressures on 134 are higher then R12. R134 systems were originally done with barrier style hoses as supposedly the particles on the 134 is finer then that of R12.
Performance wise if done correctly you will feel no difference between the 2 systems. I have had a bunch of people claim R134 does not cool as well. I have played with the system on my truck and I coul dget it down to blowing out of the vents at 35 deg f. So 134 performs just fine. it is all about the prep time you put into the job and doing it right the first time out.

 

[dorough]

To convert to R134a, you need to discharge all the R-12 (disclaimer: it's illegal to vent it yourself), fix any leaks (ideally, you should change all the o-rings in the system. If some are too much of a PITA to get to, don't worry about it), change the accumulator, drain all the mineral oil from the compressor, add ester oil, vacuum the system down and check for leaks, and recharge with R134a.

The fella I bought it from said he checked the vacuum on the system after he replaced the O-ring and it held, but he didn't charge the system. So a few questions from here... 1- Won't the system lose the vacuum when I swap out the new connectors for the old ones? 2- How do I change out the accumulator? Is that an AutoZone part? 3- The seller had also put a rebuilt compressor in, so how do I determine what kind of oil it has in it? And if it has the mineral oil, how do I change it?

Sorry for all the dummy questions... Once again I'm just trying to learn something new and save a buck.

 

[exbass94]

If you disconnect any AC lines or remove any component, you will lose all vacuum. Installing the service port adaptors doesn't require disconnecting anything, but replacing the accumulator does. You can get an accumulator at any parts store. Pretty much all the oil is going to be in the compressor and the accumulator, so if you replace the accumulator and drain whatever's in the compressor, you can start fresh. Remove the compressor and stand it on it's end and let the oil drain out. Spin the clutch as you do this. When it's empty, add about 3 oz of Ester oil. Spin the clutch by hand again to let the oil get distributed in the compressor. Reinstall it in the truck and try not to let any oil spill out. Pour the rest of the oil in the new accumulator. The total oil capacity is 7 oz, so I would pour about 3 oz in the compressor, and 4 oz in the accumulator.

 

[AllanD]

I still have a SEALED 30# can of R12 as well as several 12oz and 16oz cans

I have no clue what I'd use it for because all my vehicles have been set-up for R134 already...

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[Elwood "C"]

I still have a SEALED 30# can of R12 as well as several 12oz and 16oz cans

I have no clue what I'd use it for because all my vehicles have been set-up for R134 already...

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Hey! You still got any of that R-12 around? I've got a perfectly good system [if I can find my leak] & I REALLY don't want to refit for 134a on my 400K {& counting} '90.