134a vs r12 conversion procedure/comparison

[Racerseks]

New to the forum here. Greetings to fellow enthusiasts of in my opinion, the most beautiful corvette generation.....the C4! Of course, being 35, my opinion is a bit biased having grown up primarily with this model (smiles). I got my first C4 in 1989.....an '86 torch red coupe, and now after a 13 year Corvette absence, I once again have an '86 coupe. This time in Dark red metallic.

I've had the car a couple of days, and uh-oh.....noise from the AC compressor. Bearings? Clutch? Compressor itself? Not sure yet.....about to check it out a little further.

But assuming the worst, I'd like to hear (or be referred to threads) on people's experience with R12 to R134a conversion, and it's pros and cons. Cost of R12 charging these days (beleive it or not, this is my 15th car.....and I have NEVER had an AC charged, ha-ha).

I've heard Corvettes don't seem to respond well to the conversion due to condensor heat transfer. Any opinions?

Also.....I have a fair amount of skills and patience, and am trying to find a basic AC compressor and/or conversion procedure instruction on the internet. Can anyone help?

Thanks!

 

[nyernga]

Congrats on having a 2nd Vette go-around. I had 30 years between my first one and my 88. The conversion involves changing fittings, "O" rings, compressor oil just to name a few. Personally I prefer the speed that R-12 has in absorbing heat. If you are certain that you have no leak in the system then I'd stick with either R-12 or R-416a which can be used as a replacement for R-12 once you've pulled a good vacuum. It's less expensive then R-12, has a very similar temperature/pressure glide and is not in short supply.

Again...this is my PERSONAL choice and what I've already done with my 88.

Len

 

[Racerseks]

Thanks! It's good to be back.....and the thrill is there just as much, if not more than it was at 19, ha-ha!

Appreciate the info. Again, I've never had to charge an AC.....guess I'm lucky. Are we talking about a very substantial difference in price? I know I
can't purchase R12 myself, but by the reaction of most internet posts I've seen on the subject, you'd think R12 is like $200 a can.....and through research it seems like it runs more like $15-$20 a can or so.....which doesn't concern me all that much. If it did, I'd probably be a GEO Metro enthusiast, ha-ha. Anyway, appreciate any comments on the cost etc. Thanks again!

 

[G Winter]

I use Johnsen's Freez 12 in Older Cars , and it cost about 6.00 a 14 oz. can!! gmjunkie!!

I would like to know more about this replacement. Can you mix it? Do you use the same oil as R12 ? My 90 is a little low and should have some added but really can't handle the price of R12. I could vac it and replace with the 134A but if I could just add it would be much easier. thanks .

Glenn

 

[Robertwav1]

I do alot of A/C work on all types of Vehicles ! The last 30 lb tank of R12 I bought was $524.00 and it is 30 lb with tank!! I retro fit most newer vehicles to 134a never had any problem's 134a is tricky 1 oz too much it won't work Properly 1 oz low it won't work Properly ! It must be weighed in. R12 system is more forgiving!! I use Johnsen's Freez 12 in Older Cars , and it cost about 6.00 a 14 oz. can!! gmjunkie!! Oh Yea!! Welcome to

I still use 12 and reluctant to do a conversion. I've had a lot of problems with 134a. I do a lot of hermetics and the newer stuff for some reason causes a waxy build up in cap tubes and small orifices causing freeze ups and early compressor failure. A filter doesn't help cause the buildup comes from the 134a and oil which the filter does not block. I'm not sure if an open drive comp such as that in a automobile is very much different. There are 12 substitutes such as Jesse had talked about...I would be partial to use them rather then a conversion...Just my opinion...Oh Lord, it's getting to be AC time again!

 

[Racerseks]

Thanks for the info! Oddly enough, it's nice and quiet now.....my belt tensioner seems to vibrate a bit.....after a little belt spray, it seems to be quiet. Should the belt tensioner vibrate a bit to the point of it being visually obvious? Not sure the AC thing isn't a problem or not, but for now it seems okay.....gonna keep an eye on it over the next few days. Thanks again!

 

[Robertwav1]

To do a Proper Retro fit "You Must Flush Entire System and Replace Dryer & Orfice tube and all o-rings with green ones!" I flush each hose and cond.and evap.!! Dump old oil out of comp.and Flush as best you can! Paraphine& mineral oil Base Oils Will Gum up the work's!! Change GM orfice tube to a "Ford" Blue Tube!! Re ajust Low Pressure Switch to shut off at 22-23 lb insted of 25-27 lb some low presser switch's are not ajustable and should rep. with new 134A switch! {Frezz up will happen if this is not done} Add 8-12 oz. Ester oil, dep.on Cap. Use 10% less 134a than Freon! I weigh it in !! 1 oz either way the sys. will not work Properly!!!!! Feel Free to call me Toll Free 1-877-677-2984 Ext.1 or 2 if I dont anser leav mess on my PBnext I'l get back to ya with in a hour or so!! I'v never had any Problems with Freez 12!! I'v Been usen it for 6 Year's Call I will tell you more about it!! This took me 30 min I can't type worth a Damn!! gmjunkie!!

Well noted there gm. Your type time is worth it...I'll keep a copy for myself. I just wanted to mention that a lot of new stuff "not retrofit" is not holding up as well as the older 12. The combination of R-134a + POE oil cleans everything from inside the copper tubes and the result is obstruction in the cap tube. This seems to be the nature of 134a for some reason...at least in hermetics anyway. The health risks with 134a is also an issue. 12 is bad for the enviorment yet unless it's near flame it's not toxic to humans. 134a on the other hand is very toxic to humans and yet it's enviorment friendly. This is confusing to a lot of people...I know several years ago when all this certification became necessay I was told back then that if it is proven that 134a causes too many problems it too will be taken out of production. Thanks for the info on the conversion!

 

[G Winter]

Robertwav, thanks for the heads up on the 134a toxic thing. I wasn't aware of that. Be assured I will be much more careful with it. On the GM airconditioners the screen and orfice are easily replacable. It does mean a vac and recharge though. I have changed a numger of systems over to the 134a without draining oil and flushing the system and haven't had a failure in 6 yrs.

 

[geekinavette]

Hey Junkie...have you ever used Envirosafe? (hydrocarbon based). I used this in my Astro Van...so far so good.

Bill