Quesrion Re: A/C Old (1982) Car

1,191 Views | 15 Replies | Last: 2 yr ago by chimpanzee
combat wombat™
How long do you want to ignore this user?
AG
Forgive me if I use the wrong terminology.

The AC on our Corvette is cooling, but not well. If it's really hot out, it's not going to cool much at all. We think it has a freon leak. It was charged and worked great, and then the next day, not so much.

This is an old AC system that takes the old-school freon. The mechanic my mom has used since about 1982 can't get it. He mentioned having done a lot of conversions about 20 years ago - retrofitting the AC systems to take the new freon.

I have a few questions about how to move forward. Obviously, we need to find the leak. He was going to put freon with dye in it... but then didn't have the correct kind of freon. It there another way to do this... maybe an inert has with dye? Is this guy just not knowledgeable enough?

Do I need to retrofit for the new freon? I'd rather not, but if I won't be able to find the old freon how do we fix this?

Completely unsure how to proceed... planning to see another mechanic soon to see if they can fix it.

Lastly, can anyone here recommend a good mechanic in Houston? We live near Jersey Village, but I drove to Sharpstown today to see my mom's mechanic so I don't mind a bit of a drive.

magnumtmp
How long do you want to ignore this user?
AG
combat wombat said:

Forgive me if I use the wrong terminology.

The AC on our Corvette is cooling, but not well. If it's really hot out, it's not going to cool much at all. We think it has a freon leak. It was charged and worked great, and then the next day, not so much.

This is an old AC system that takes the old-school freon. The mechanic my mom has used since about 1982 can't get it. He mentioned having done a lot of conversions about 20 years ago - retrofitting the AC systems to take the new freon.

I have a few questions about how to move forward. Obviously, we need to find the leak. He was going to put freon with dye in it... but then didn't have the correct kind of freon. It there another way to do this... maybe an inert has with dye? Is this guy just not knowledgeable enough?

Do I need to retrofit for the new freon? I'd rather not, but if I won't be able to find the old freon how do we fix this?

Completely unsure how to proceed... planning to see another mechanic soon to see if they can fix it.

Lastly, can anyone here recommend a good mechanic in Houston? We live near Jersey Village, but I drove to Sharpstown today to see my mom's mechanic so I don't mind a bit of a drive.




The conversion will be to R134A. I'd proceed with the conversion and have them put dye in. R134a is relatively inexpensive and can be purchased over the counter. They will pull a vacuum prior to charging….that's a good time to look for leaks and may avoid the dye anyway.

I'd be careful putting an inert gas in there, although it's an intriguing idea. I definitely wouldn't run the compressor if you do, which means you'd have to pressure the whole system to 350 psi. No way I'd do that to save ~$50 of r134a.
TxAg20
How long do you want to ignore this user?
AG
As a teenager, I helped my dad convert a few R-12 systems to R-134. I don't think the converted systems worked as well as they did with R-12.

I'm not sure how tough it is to find R-12 today, but I wouldn't convert to R-134 unless it's cost prohibitive to refill with R-12. In any event you need to find your leak(s) first. I would take it to an automotive A/C specialist. They should have the resources to find the leak and refill with R-12 if R-12 is available at all.

An auto A/C specialty shop should also be knowledgeable about R-134 conversions and how to do them correctly. The kits my dad used were less than $100 at the chain parts stores. R-134 may need a different compressor, condenser, or dryer to work correctly in an R-12 designed system.
Burdizzo
How long do you want to ignore this user?
AG
TxAg20 said:

As a teenager, I helped my dad convert a few R-12 systems to R-134. I don't think the converted systems worked as well as they did with R-12.

I'm not sure how tough it is to find R-12 today, but I wouldn't convert to R-134 unless it's cost prohibitive to refill with R-12. In any event you need to find your leak(s) first. I would take it to an automotive A/C specialist. They should have the resources to find the leak and refill with R-12 if R-12 is available at all.

An auto A/C specialty shop should also be knowledgeable about R-134 conversions and how to do them correctly. The kits my dad used were less than $100 at the chain parts stores. R-134 may need a different compressor, condenser, or dryer to work correctly in an R-12 designed system.



Back about 1993 I bought two 30# cans of R-12 when the government was about to ban it. One is now empty, and the other other is about 3/4 full. The problem I have now is only one vehicle I own still uses R-12. That vehicle has a refrigerant leak, and I never drive it anyway.

My brother has several pieces of farm machinery that might still use R-12, but most of his stuff has been converted to R-134 also.

My advice to the OP is to bite the bullet and get the AC converted. R-12 is next to impossible to find, and is expensive when you find it. Chances are that you will be chasing leaks in the 40-year-old system for a long time. Might as well leak R-134 instead of R-12.
combat wombat™
How long do you want to ignore this user?
AG
Thanks, folks.. I convinced my husband to keep the Corvette but as part of the agreement I am now responsible for having problems with it repaired. The 1st thing I need to have fixed is the air conditioner.

I found this article which was extremely helpful.

https://www.hagerty.com/media/maintenance-and-tech/fixing-vintage-air-conditioner/
Silvy
How long do you want to ignore this user?
AG
I don't know much about them, but there are r-12 substitutes that can be used instead of r-134 retrofit. One of these products is called Freeze 12.
UmustBKidding
How long do you want to ignore this user?
All the r12 drop ins i know of are in theory not allowed in cars since they are flammable. Of course i know many that use them and swear by them over r134. Of course the new r1234yf in cars is mildly flammable.
Also if you have any leaks r134 is be gone immediately since it a far smaller molecules than r12. Why r134 systems dont have rubber hoses.

JP76
How long do you want to ignore this user?
I've used freeze 12 many years ago and it worked great. Not sure it is still available though. Back in the day i also converted a few r12 to 134a. Of the 10 or so I did all but one for them kept running for years. One the compressor failed on and while you could blame the conversion, it also had over 200,000 on it. If it was me , I would put some dye in it to find the leak. Fix that problem and then covert it to 134a.
combat wombat™
How long do you want to ignore this user?
AG
The shiop my husband uses specializes in Corvettes. They quoted about $2k to fix it/convert it. They say the compressor is bad in addition to the leak. Needs compressor, condenser, dryer, orifice. And freon (R134s... they'd have to convert as part of repair). I thought this was too much but am starting to wonder if I'm wrong.

There is NO WAY we can do this repair ourselves.
Endgame@work
How long do you want to ignore this user?
CUSTOM CAR COOL
14800 Hempstead Rd
Houston, TX 77040
Phone: (713) 680 9664
Rexter
How long do you want to ignore this user?
The main issue with an r12 system running r134a is the needed increase in airflow across the condenser to remove the heat. The conversion works best with high-flow electric radiator fans.
txyaloo
How long do you want to ignore this user?
AG
UmustBKidding said:

Also if you have any leaks r134 is be gone immediately since it a far smaller molecules than r12. Why r134 systems dont have rubber hoses.


Huh? I'm fairly certain these hoses are made of rubber...

UmustBKidding
How long do you want to ignore this user?
Modern ac system hoses are nylon lined to prevent moisture ingress. In the r12 days this lining was internal. In r134a world this is typically external. The change is that the lube oil in the system, Pag is typically used in r134 systems mineral oil in r12. Pag reacts with the nylon and also with materials used as desicants in the receiver dryer. This is why during r134a upgrade the dryer and oil charge has to be changed. Leaving the hoses is a compromise and usually works because the lining is saturated with the long term exposure to mineral. Oil and helps protect it to pag.
96 is a long time ago so exact details are in the fog.
L
1agswitchin4lanes
How long do you want to ignore this user?
AG
Endgame@work said:

CUSTOM CAR COOL
14800 Hempstead Rd
Houston, TX 77040
Phone: (713) 680 9664

These guys are excellent but pricey.

If your 82 vette is a keeper, its worth spending the $
combat wombat™
How long do you want to ignore this user?
AG
Well, it's worth getting an estimate. The place we go to is expensive, too.
Tim Weaver
How long do you want to ignore this user?
Lots of hearsay being thrown around in this thread.

R12 is abundant and available globally. Just not in the US.

In fact there is kind of a surplus of it since nobody uses it anymore. Problem is, nobody uses it, so no one in the states will get it or deal with it for you. If you can go to Mexico you can buy it legally through a household HVAC supplier. They still stock it because there are enough old house AC's still using it.



R134a is not as efficient at cooling as R12 is. Therefor using the compressor, condensor, and evaporator designed for a more efficient gas will underperform on a less efficient gas. That's just physics. There is not a lot you can do about this, but if you add an auxilary fan to the condensor (the radiator looking part in the grill of the car) you can help make the system a little more efficient at removing heat.


Now about the R12 alternatives. Freeze12, Maxi-Frig, Duracool, etc. These are just propane or a propane/butane mix. Surprised? Yeah you can actually run camping propane in your R12 AC and it'll work just fine. Problem is camping propane is not very pure. It has water and other contaminates in it and will destroy the AC system after a while. Those R12 alternatives are just a well purified Propane gas. Sometimes with some Butane mixed in. As for it being flammable? Who cares! You are literally driving around with 10-20 gallons of gasoline! 10-ish ounces of propane makes little difference when you remember what's in the back of the car!

One great thing about the Propane solution is IF you have a leak, Propane is a safe hydrocarbon. It will not attack the ozone, nor will it contaminate groundwater supplies, or anything else. In fact factories run forklifts on propane indoors to prevent fouling the air quality. R12 and R134a are much worse for the environment. R12 (and R22) are the worst offenders of ozone depletion, but it's now understood that R134a contributes to global warming as well.


So in my opinion the best way to acheive a truly functional AC system is to feed it the R12 it was designed for, but barring that you should be using the propane based alternatives which are on-par with R12's efficiency. But if you have to use a garage to do the work, R134 is the easiest gas to have a third-party use for easier servicing of your car.

Pretty much every auto shop will not touch R12 or Propane because of liability reasons. R12 is illegal to sell in the US (in the automotive industry). Has been since 1994. Home HVAC guys still seem to be able to get it and maybe if you ask around enough you might find somebody that will sell you some on the down-low, but just know that is illegal for them to do unless they are personally refilling your house AC.
chimpanzee
How long do you want to ignore this user?
Vintage Air out of San Antonio does good work. Unless you're hung up on originality, try something like this:

Vintage Air Search Results - Vintage Air (Part number 964176 if the link is wonky.)

I installed a similar kit on my Trans Am. You can do it yourself if you're handy The toughest part for me was figuring out that I had a bad fuseable link that sometimes worked and sometimes didn't. I didn't have much space under the dash, but you would have less in that C3 (I had an '81), so there would be an element of "sword fighting in a phone booth" that is worth paying someone else to do.

Presuming you're in TX - here's a list of shops that handle it...

Vintage Air Distributors - Vintage Air

Refresh
Page 1 of 1
 
×
subscribe Verify your student status
See Subscription Benefits
Trial only available to users who have never subscribed or participated in a previous trial.