1968 Chrysler 300 A/C HELP!!

[bronze turbine]

My mechanic just charged my a/c with R-134a. He made NO changes to the system. What should I do? Should I purge the system of all gas immediately and unplug the compressor so it doesn't run? I thought to convert to R-134a you had to make a lot of changes to the system. I didn't want that, I just wanted it charged with R-12. What should I do???

 

[commando1]

You just can't drive to any old shop, ask them to charge your system, and expect them to use R12. That hasn't happened in 20 years.
Licensed shops can't even use R12 anymore.
Have them evac the system and give you a credit twds charging your system after the o-rings have been replaced. And preferably the hoses, too.
That is, if the R134a wasn't contaminated. Then your screwed.

SUMMARY: Go to a better shop.

 

[Davea Lux]

You should also find out if this shop purged all of the R-12 oil from the system. R-134a is not compatible with the R-12 oil, when mixed together the oil forms a thick snot that is useless as a lubricant and clogs everything up. The compressor always fails in that situation. The system should have had the filter dryer replaced after several hours of evacuation to boil off the old oil. O-rings and the low side hoses should also be replaced as noted. Pagg oil and a new filter dryer are then added. System is then re-evacuated and R-134a is added. RV-s compressors have a high failure rate running R-134a because of poor oil circulation. R-134a is a smaller gas molecule and it does nor push oil thru the system as well with a reciprocating compressor and the smaller gas molecule makes the R-134a more prone to leak out, this results in lower gas pressures and the compressor fails from lack of lubricant. When the gas pressures drop the oil stays in the condenser, filter dryer and evaporator and does not return to lubricate the compressor. In short, you may have major problems on the horizon, unplug the compressor until you find out what was done to convert the system.

Dave

 

[TxDon]

Some unanswered questions: Was the system completely empty or only partially charged? Were the charge ports converted to 134 style or original? Was the system working at all before the recharge? I agree with commando you need a better shop but you also need to do some research.

My own experience - the system on my wagon was partially charged and had been "converted" to 134 without changing any parts. I recharged it and added some oil and it worked great for a month - before the RV-2 compressor locked up. Now I am doing a complete underhood conversion.

 

[Xenon]

bronze turbine
Would you mind posting up couple pics of your 300....
Thank you......................

 

[Lefty71]

Never heard of refrigeration oil "boiling off". We always blow an acetone spray through to thin out and remove the mineral oils that were used with R-12 and R-22, before recharging with the new CFC free refrigerants and the proper oils. The new blends need a synthetic oil and they are not compatible. This does sound like a mess, but I'm sure it will be fine if you haven't run the compressor, just unplug it and get to someone who knows how to do the job properly. Also, R-12 is not really gone, and state laws might vary I guess, but to my knowledge its not illegal to recharge with R-12 if anyone has any left. It only makes sense that this was its intended purpose, it's not like a technician is doing anything with it other than what its intended for (and no one is making more). I'm not a lawyer, and could be wrong about this. But I do know the stuff is still around, to a very limited degree. HTH, Lefty71

 

[Xenon]

Here is a well written article on refrigerants and the use of ..
Air-conditioning dos and don’ts: Refrigerants and the law | Hagerty Articles

 

[commando1]

you had to make a lot of changes to the system. I didn't want that, I just wanted it charged with R-12. What should I do???

He wasn't looking for UTI Technical School HVAC Associates Degree.
He asked what he needed to do.

He needs to go to a decent Accredited Auto A/C shop.
TELL THEM WHAT HAPPENED.
Hope to evac the R134a.
Change the O-rings.
And the oil (thank you, I did omit that part but a good shop would do that anyway. Along with the drier).
Hope to be able to reuse the reclaimed R134a.
Some shops won't touch it because they won't reclaim contaminated refrigerant. Hazmat disposal and all that ****.

You guyz trying to teach him all this **** A-Z is moot. If he repeats this stuff to a good shop, they'll say, Yah, yah.. OK.

 

[Davea Lux]

Never heard of refrigeration oil "boiling off". We always blow an acetone spray through to thin out and remove the mineral oils that were used with R-12 and R-22, before recharging with the new CFC free refrigerants and the proper oils. The new blends need a synthetic oil and they are not compatible. This does sound like a mess, but I'm sure it will be fine if you haven't run the compressor, just unplug it and get to someone who knows how to do the job properly. Also, R-12 is not really gone, and state laws might vary I guess, but to my knowledge its not illegal to recharge with R-12 if anyone has any left. It only makes sense that this was its intended purpose, it's not like a technician is doing anything with it other than what its intended for (and no one is making more). I'm not a lawyer, and could be wrong about this. But I do know the stuff is still around, to a very limited degree. HTH, Lefty71

Acetone is a good solvent, but it has to be used in a closed recovery system. Highly flammable and potentially explosive. Fire department wanted us to install explosion proof heating and air circulating equipment in the shop if we used this method. The mineral oil used in automotive system would usually start to boil in about 20-25 in vac. Takes a while but it does work.

Dave

 

[bronze turbine]

I actually found the article quite interesting and informative. My mechanic said he had the system on the vacuum all afternoon, but when I went to pick up the car he hadn't charged it yet. I asked him if he was going to use R12 but he said it would work fine with the R134A you just have use less of it (or more, can't remember his exact words). I never saw him add any oil whatsoever. I'm no mechanic but that whole episode didn't look right to me (I was having visions of my compressor seizing halfway to Carlisle). The compressor is currently unplugged and will remain so. Heck, it's a convertible anyway. Who needs air conditioning?

 

[detmatt]

I love my power vents!

 

[300C]

bronze turbine
Would you mind posting up couple pics of your 300....
Thank you......................

I read your request of Bronze Turbine.....And I thought I would post these, though it has nothing to do with the AC question...damned stupid shop!!!!

This Turbine Bronze '68 300 is un-restored and was purchased new by my folks in 1968 June. I was 11 and remember seeing the car pull into the driveway. It's unmolested and all original with the usual wear and tear but despite some of that it shows well. Dad was a Depression Era guy so this is a 440CID with crank windows and NO A/C....runs beautifully and fast as the devil! I have had it since 1974.

I hope those YAHOOS can do something about that A/C SNAFU. Any more, it's become "DIY" or don't do it at all....and the older we get the more difficult it is. Finding parts for these cars never was easy....finding r12 isn't too hard but it IS pricey. I converted my '64 Imp to 134a at restoration and while it works it is not as well as the 12. We prefer to put the top down....

Good Luck on the fix. Lots of good info here on what to do!

 

[Imperialist67]

THANKS for sharing the photo of this bronze beauty. 4-door 300's aren't real common, but I think flatter the slab-sided styling, especially with the black vinyl top. Crank windows break down a lot less than power windows do, and the cowl vents on these cars ALMOST cancels out the need for AC.

 

[300C]

THANKS for sharing the photo of this bronze beauty. 4-door 300's aren't real common, but I think flatter the slab-sided styling, especially with the black vinyl top. Crank windows break down a lot less than power windows do, and the cowl vents on these cars ALMOST cancels out the need for AC.

Thanks! You know what's interesting, Dad traded a '65 Impala for this car and it took 3 months for delivery. WHen he brought it home he said this was a "sport" model and I'm not sure if he meant "SPORT" as in fast....b/c it IS! OR if he was referring to the "300 Sport" model vs. the former letter series. Whatever, it was a few years later that I saw an ad in an old Popular Mechanics, 1957, for the 300C and I was bitten by the MOPAR bug, C bodies only. I have had a number of them....this one is hard to beat. Do I wish it was a coupe? Sure? A convert? Absolutely....but they did a great job on the roof line and true, with those cranked vents open, at 80+mph you don't need A'C! Thanks for your interest.

I'm ALWAYS amazed at what shows up here....best site!!

 

[Trace 300 Hurst]

I just wanted to add that R12 is VERY available, but it cost a lot more than the 99 cents per can from the old days. Lots of people selling oldish cans, and there's this brand new Sino freon.

Pure R12 F R-12 Refrigerant W/Tap & Hose 3 Rust Free Cans = 2.25lb Total S3TH | eBay

R12 Refrigerant R-12 3 Cans $29 Per Can! 12 oz Rust Free! Genuine and Pure!! | eBay

 

[300C]

Thanks for those links! I also have a cache of r12 which I use in the 300C. I won't convert that one. When we restored the C some years back the shop used Freeze12, and it worked GREAT! I still have some and it's compatible with r12.

Now, what are WE all doing about the next phase of A/C work, the phase out of r22? UGH!!!!!!!!!!!!!!!!!!!!

 

[Lefty71]

Now, what are WE all doing about the next phase of A/C work, the phase out of r22? UGH!!!!!!!!!!!!!!!!!!!!

Manufacture of R-22 ends next year. People have been griping about R-410a since its inception. The pressures run way too high and its hard on things because of this. My guess is next they'll be telling us that R-407a is the wave of the future and the new jobs creator......

 

[Trace 300 Hurst]

Thanks for those links! I also have a cache of r12 which I use in the 300C. I won't convert that one. When we restored the C some years back the shop used Freeze12, and it worked GREAT! I still have some and it's compatible with r12.

Note: Regarding the Sino cans, it seems they are for some European style screw-on tap, but you can use a clamp-on tap as is common here, or a side-pierce tap, or get the Sino cans with an included Euro tap with hose.

 

[Davea Lux]

Thanks for those links! I also have a cache of r12 which I use in the 300C. I won't convert that one. When we restored the C some years back the shop used Freeze12, and it worked GREAT! I still have some and it's compatible with r12.

Now, what are WE all doing about the next phase of A/C work, the phase out of r22? UGH!!!!!!!!!!!!!!!!!!!!

It gets worse, R-134a is also headed to oblivion, under the proposed regulations, that should happen in 2026. Already being phased out of new vehicle construction. Most of the other R-12 replacements are flammable and will also be banned. The replacement for '21 model year cars, HFO1234YF has a dealer net of $70 per lb.

Dave