R12 or R134 how to tell?

[T-Keith]

Well it's starting to warm up here in MN and I'm starting to think about AC. I bought my 88 Lesabre last fall and believe it or not the AC still works at 210,000 miles.

However, the compressor is a little noisy, and I'm thinking that topping off the lubricant would be a good idea. However, I don't know if it's the original R12 or it's been converted and I don't want to mix. Is there are way to tell? I don't think I'll be able to get any shop to look at it without a huge bill either.

Anybody have any ideas?

-T

 

[Chris142]

Take the car to a shop. They will have a refrigerant identifier. Shouldn't cost you anything for them to test the refrigerant. Takes about 3 minutes.

 

[kenw]

a converted or original r134a system will have a much larger hose connector on the low pressure line. The r12 version is a screw-on schraeder valve, a bit larger than a tire stem valve. The r134a is usually a quick-connect (nonthreaded) connector almost 1/2" in diameter. (On a converted system, the quick connect r134a valve screws onto the existing r12 valve.)

Now, understand it IS possible that someone converted it without changing the valve, but that would be unusual.

 

[Chris142]

quote:

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Originally posted by kenw:


Now, understand it IS possible that someone converted it without changing the valve, but that would be unusual.

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I see this daily!

 

[T-Keith]

I've never seen anyone change parts for a retrofit sytem? It would have originally had R12.

I'll try calling around to some shops, but somehow I doubt I'll get anything for free.

-T

 

[Schmoe]

If the conversion was done at a licensed shop, then there should be several stickers around the engine area saying that it had been converted.

 

[JohnBrowning]

Most conversions do not last long if all of the parts were the OEM R12 parts. You tend to run into oil/o-ring compatability issues, seal failures due to increased working pressure, contaiments from old system etc.....

Some people think it is ok to just change the pressure cut switch's cycle switch etc... flush the system and recharge with R134A. It usualy blows out in a year. Now if you replace the condensor the switch's,lines,flush new o-rings and compressor with one built or rebuilt since 1996 the conversion tends to do just fine!

If it was done by a ASE certified Tech. their will be stickers under the hood indicateing the retrofit and the valves will match the refrigerent! If my memory is working right all GM vechiles by 1996 had R134A in them!

T-Keith, are you attepting to recharge it with a R134A Top-Off product?

 

[kenw]

quote:

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Originally posted by JohnBrowning:
Most conversions do not last long if all of the parts were the OEM R12 parts. You tend to run into oil/o-ring compatability issues, seal failures due to increased working pressure, contaiments from old system etc.....

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urban myth for 99% of the cars out there. my mechanic has done hundreds and none failed. I've personally done/supervised at least a dozen, none have failed. Nothing but the rec/dryer was changed on any of them.

a/c units that are leaking before they were converted will still leak. If you are converting a system that's low on freon, it's already leaking. the seals didn't fail because of the conversion, they were already leaking!

 

[T-Keith]

I plan on topping it off with the appropriate product, but I don's want to use the wrong one. I've converted several cars before and the only problems I've had were existing leaks. If I need to I'll convert it and properly dispose of the R12, or if I can I'll just add some R12 lubricant to it.

-T

 

[kenw]

if you know it's leaking i would recommend you go ahead and convert it.

 

[T-Keith]

I don't think it's working otherwise it wouldn't have lasted through the winter. The compressor is just loud and I've heard that topping off the oil works well for this.

-T

 

[serious II]

Good luck trying to get you hands on any Freon (R-12) : you would have a better chance of obtaining plutonium ( and the plutonium would be cheaper).

 

[T-Keith]

I called around, no one has such a machine capable of telling the difference. Anyone else have any ideas? You would think that the government would want you to be able to dispose of R12 properly, but it seems like the only way to get rid of it is to let it into the atmosphere.

-T