: A/C Conversion on Brougham



Caddylover86
04-24-11, 03:35 PM
hey i was just wondering which direction most of you have gone when it comes to replacing the old R-12 A/C system and how difficult is it to change over to R-134a

sven914
04-24-11, 11:10 PM
134a doesn't cool as well as R-12. If you live anywhere where it get hot in the summer, you will be miserable. People who live in the northern Untied Stated and Canada can usually tolerate the lack of cooling.

With the upgrade to 134a, you need to retrofit the entire A/C system. You need to have an HVAC technician change the accumulator/ receiver dryer, replace the compressor, flush the lines, and install 134a compatible service ports.

An alternative to R-12 is a product called Freeze 12 (http://www.freeze12.com/). Freeze 12 is completely compatible with R-12 refrigerant and R-12 components. You can have your system recharged with that and not need to change any parts or flush the lines or even have the existing freon evacuated. The best part is that it cools just as well as.

Sponson
04-24-11, 11:13 PM
I switched to 134 in my 69 caddy. System was sucked down, oil that is compatible with R12 and 134 was added (ester oil if I remember correctly), and the system filled. Worked fine.

Sponson
04-24-11, 11:20 PM
You do not have to change out the entire system. My system works fine with the original equipment. Check out this site. If the system is opened (to change a line for example), it would be a good idea to replace the dryer, not for compatibility reasons, but because it has dessicants in it which after a while become less effective as it soaks up moisture. Driers are not expensive. $20 for my 69 Caddy. My system still blows pretty cool, not as cool as R12, but cool.

http://www.epa.gov/ozone/title6/609/technicians/retrguid.html#lubricants

sven914
04-24-11, 11:21 PM
^And where do you live?

jayoldschool
04-24-11, 11:46 PM
As mentioned, compressor does not need to be replaced when switching to 134a. I converted my 92 Roadmaster wagon, and my 81 was converted before I got it. Both have great AC. Yes, I am in Canada. Normal temps in June/July/August are high 80s with high humidity.

sven914
04-24-11, 11:57 PM
The R-12 compressor will pump 134a but the seals will leak. To do it right, you should replace everything, but it will work either way.

Caddylover86
04-25-11, 12:14 AM
i live in denver, gets pretty hot up here to my suprise. yeah i dont want to spend an arm and a leg to get all the hoses and lines converted.

Caddylover86
04-25-11, 02:13 AM
also im hearing a ticking/ tapping noise thats for sure coming from the compressor. idk why but when the clutch engages on the compressor the noise goes away. think its time for a new compressor?

turbojimmy
04-25-11, 08:31 AM
also im hearing a ticking/ tapping noise thats for sure coming from the compressor. idk why but when the clutch engages on the compressor the noise goes away. think its time for a new compressor?

Might be the bearings on the clutch going. Mine started out as a tick, then a squeak. Now it's a gawd awful screeching sound. It stops when the compressor clutch engages. It's on my "to do list".

The conversion can work fine if you do it right. By doing it right, I mean replace the compressor, accumulator/drier and orifice valve. The oil in the R12 system is not compatible with the R134a. You have to get all of the oil out of the system. The only way to do this effectively is by replacing these parts. At least replace the accumulator/drier - the oil soaks the desiccant and it you can't remove it. Also, you have to charge it properly. Keep an eye on the outlet temps AND the high and low side pressures as you charge. Once the pressures are optimal, the outlet temps will stop dropping. A common mistake is replacing the R12 with R134 on a 1:1 basis. That is, if you have a 3.25 lb. R12 system, people will blindly put 3.25 lbs of R134a in it. You actually need less R134a to do the same job.

I did my Grand National a looooooonnnnnnng time ago. At that time, I compared the outlet temps to my then-newish '97 Explorer's R134a system and my recently dealer-serviced Typhoon's R12 system. The converted GN was the coldest. I wrote up an article at GNTTYPE.org. It's here:

http://www.gnttype.org/techarea/airconditioning/R12toR134a.html

Jim

Sponson
04-25-11, 09:02 AM
To answer sven914 question - I live near Philadelphia PA. Summers easily get into high 90s. The car does cool, again not quite as well as with R-12, but it does cool. You also have to remember that the air flow on cars from the 60's was not nearly as good as cars today.

pompste
04-26-11, 12:30 AM
I changed my '78 Deville`s AC to 134a with the appropriate oil and it works fine---no leaks so far since i changed it over a year ago.The system was bone dry when i bought the Caddy, a year and a half ago, so nothing vented at all.
It cools quite well,temps do get in the 90`s here with high humidities in Michigan--i just keep the fan on high.
R-134a is a smaller molecule than R-12,so if any minor leaks show up,i`ll just add more refrigerant with "stop leak" already in it.

jayoldschool
04-26-11, 10:20 AM
Don't add stop leak. Horrible stuff. Do a quick google for lots of results...

pompste
04-28-11, 01:23 AM
Don't add stop leak. Horrible stuff. Do a quick google for lots of results...

Apparently stop leak does`nt work for some,but i`ve never had any problems with the stuff.If it was that bad i don`t think they`d still be selling it.I saved my old '84 Camaro`s and '88 Ford Cougar`s AC systems by using the stop leak.I donated both cars to local charitable organizations 5 years back,then i bought my 2 Caddy`s.
I think the stop leak is just used for AC systems with very "minor" leaks anyway.Thanks for the info though.

RocketFast321
04-29-11, 04:10 PM
I use to think my girls 90 cutlass calais was r12 but it's 134a. Cools real good on a 100f day with 100%humidity. The only problem is at idle. The r12 compressor is not pumping fast enough. But as long as you are moving it's good. It has all OEM r12 stuff from the looks of it.

But I went to school for HVAC so a car is same. New orifice tube and accumulator are really the only things you need. And the right oil too. Seal everything up and vacuum the system. It should hold a vacuum.

bradmo
05-21-11, 02:43 PM
Since the middle '90s I have converted about 20 of my personal cars and over 100 at my car lot over to R134a with the only change the add on of the cheap charging adaptor (purchased at Pep Boys, O'Reilly, Advance). I have rarely vacuumed the system first, just added new 134a.
You lose no charge when you install the adaptor.
I know it is not correct, but I have never had a problem yet.
Yes, I do need to add another 12oz can of R134a occasionally, every 2 - 4 years or even less.
Occasionally I haved added a can of R134a with the sealer in it and have seen no problems yet.
Over 15 years on some of these now, and no problems.
Summer temps here into the 90s with high humidity.
The coldest I had was a '94 Ford LT 9000 dump truck that would put out 36 degree air from the vents at a 900 rpm fast idle...

brougham
05-22-11, 03:06 PM
You don't need to change the compressor unless it has problems. Change the seals at the hoses or the hose that's bad because that's the most typical spot for leaks. Don't bother with stop leak stuff, fix it right and then you don't have to deal with it again.

Bro-Ham
05-22-11, 09:49 PM
I tried 134 once, on my 76 Fleetwood Brougham I owned 8-9 years ago which had less than 10,000 miles on it. Had a professional AC company change it over and I immediately found the 134 in that long car didn't cool sufficiently so I immediately had it changed back to R12. After that experience I won't use anything but R12 in my old big Cads including my current 79 deVille which has R12 AC that cools like the arctic. :)

pompste
05-23-11, 10:55 AM
I tried 134 once, on my 76 Fleetwood Brougham I owned 8-9 years ago which had less than 10,000 miles on it. Had a professional AC company change it over and I immediately found the 134 in that long car didn't cool sufficiently so I immediately had it changed back to R12. After that experience I won't use anything but R12 in my old big Cads including my current 79 deVille which has R12 AC that cools like the arctic. :)

I wish i had the bucks to have kept my '78 Deville`s AC system with R-12.I remember owning cars back in the day in the 1970`s with R-12 systems and there`s no doubt it cools better than 134a.With R-12,ice actually forms on the freon fill tank.

Bro-Ham
05-23-11, 11:32 AM
I wish i had the bucks to have kept my '78 Deville`s AC system with R-12.I remember owning cars back in the day in the 1970`s with R-12 systems and there`s no doubt it cools better than 134a.With R-12,ice actually forms on the freon fill tank.

The R12 is more expensive but I think it's worth it. The important thing is we are keeping our cars rolling. :)

pompste
05-23-11, 09:39 PM
The R12 is more expensive but I think it's worth it. The important thing is we are keeping our cars rolling. :)

Keeping our cars rolling is important for sure! I feel so good when driving my 2 classic Caddy`s around.
Maybe someday when my financial situation gets better,i`m currently unemployed here in Michigan--along with countless others,i`ll get the R-12 put back in my '78 Deville.It`s just a matter of removing 2 adapters and properly venting the 134a---and of course paying much more for the R-12.