Take a look at the fittings where you charge the system.If it has been converted they should have changed them to the 134 fittings.

 

eazy to test

Take car to an GOOD shop.They should have gas/a/c tester. This is ness. to keep from mixing gases in recovery unit.Best to stay with r12 unless condencer is changed to hi-eff model.

 

Oh, the connections on the drier are not a r-134a connection. Just regular r-12 connections.

is that what your talking about...? but whats a drier

 

Take car to an GOOD shop.They should have gas/a/c tester. This is ness. to keep from mixing gases in recovery unit.Best to stay with r12 unless condenser is changed to hi-eff model.

If you can afford the 50$$ a pound!! Well I have had pretty good success converting r12 to 134a. I generally like to remove the compressor drain it and refill with ester oil which is compatible with the residual mineral oil and is compatible with the 134A.Then change the accumulator and add 2 or 3 oz. of ester oil to that. Since it says that trace dye was added you can go to O'Reilly's and buy a black light test kit pretty reasonable. Then you can check for the leak yourself.That is probably what I would do first prior to changing to 134a. The problem with "only adding a 1/2 pound of r12"is unless you have a license to purchase it you will have to pay a shop to put it in. They will not charge you for only a 1/2 pound (all the shops I have worked at) they hit you for a full pound. Aggravating I know! especially since they buy it in 30lbs can and could charge it out by exactly how much they installed. You know what the real kicker is?? I read a report put out by the EPA a while back that said r12 isn't as bad for the environment as we once thought and that 134a isn't really that much better environmentally. I don't like to get into conspiracy theories but it sure makes you think. There are a lot of opinions on converting and there are people who say you have to do this and that and flush the system yada yada yada........ I replaced the condenser in my wifes 93 Chevy lumina car (not the van) and used the conversion kit sold at walmart(Interdynamics I think). I didn't change a thing other that the condenser and installed the charge fittings, I pulled a vacuum on the system for about an hour and added the refrigerant with the kit ,the right amount of oil was already mixed in with it. The car had 140,000 when I did it and 4yrs later when I traded it in (190000) miles it would absolutely freeze you out. Full summer heat 100* you would get it to the temp you wanted and then cut it down to low or med low fan and be very comfortable.Any way all that said if the system is in fairly sound condition with only a small leak, you should be able to fix the leak and change over to the 134. It will cool just fine if every thing is in good repair. one other thing you need to know is it only takes 80% as much 134a as it did r12. Well good luck getting cool. Brian

 

Some auto parts stores have a product that is neither r12 or r134, its some kind of proprietary thing that works in any system, and you can usually top up a leaky system with two cans of it. The cans are about $20 each I think, and there is a special valve/hose/pressure gauge kit you buy to put it in. It works really well.

 

If it don't have the big fittings I would almost have to say it has 12 in it. I would stay with the 12 for a lot of reasons. The most important one is that 134 for lack of a better explanation is thinner ( has less viscosity) than 12. I have seen more evaporator leaks than I care to mention on converted systems.

 

Official Disclaimer:
All that follows is second-hand information that was "learned through osmosis", which I believe to be true. I am a partsman ... not a mechanic.

Yes there are refrigerant verifiers that a good shop will have that will tell you what refrigerant is installed.

Most shops have them so that they don't contaminate their equipment, and many shops will ONLY service systems with either R12 or R134A for that reason.

It is illegal to mix differing types of refrigerant.

The "not R12 or R134A" refrigerant sold at many parts stores is usually a hydrocarbon based (often propane / butane) refrigerants. Red-Tek is one of the more popular brands here in Canada. They state that their product IS compatible with either R12 or R134, but DO advise that it is illegal to mix refrigerants.

R134A is "molecularly smaller" than R12, and is more prone to leakage. R134 is also less efficient than R12, so retrofitting to R134A in a system that was marginal to begin with will be noticably worse.

A/C technicians are REQUIRED by law to prominently affix a label (usually in the vicinity of the low-side service port) stating the type and amount of charge in the system.

IF you are going to be replacing major components (i.e. Compressors) also be advised that some suppliers (i.e Everco / Four Seasons) will NOT warranty a compressor if ANYTHING but approved (R12 or R134A) refrigerant is found in the system. This includes dyes and sealants ... refrigerant ONLY.

Four Seasons Compressor installation instructions

EPA Regulations / Alternative Refrigerants

 

Those Walmart Interdynamics kits are known as Death Kits in the business, because that's what they do to your system if you don't do a complete changeover.

DaSouthWon used it, and it worked for him for now, but eventually it will probably ruin the system.
The desiccant in the accumulator isn't compatible with the r134 oil, so the desiccant bag breaks down, sending the debris through the system.
The Red Tek and Duracool "replacements" are flammable propane or butane, and work very well, but it is illegal to use them. however, if I ever get around to fixing my a/c, I might be tempted to try Duracool.

 

huh? I haven't done anything to the system, thats why I'm posting.

 

no offence,but

A/c ain't cheap ,esp. on a vette.Take car to a good shop,don't mix gases.

 

I think I will just start by topping off w/ r12 to see. If that doesn't work I'll flush it out and do the conversion. What could I screw up by mixing r12 w/ r134 if it does in fact already have the r134 in there?

 

I think I will just start by topping off w/ r12 to see. If that doesn't work I'll flush it out and do the conversion. What could I screw up by mixing r12 w/ r134 if it does in fact already have the r134 in there?

Cheaping out, rolling the dice, and doing the DIY thing here (IMHO) is the wrong thing to do.

Pay a little now or (potentially) pay a lot later.

I've already mentioned that most shops use a refrigerant verifier to determine exactly what is in the system. Chances ARE pretty good that it is R12 ... but what if it isn't?

I'd STRONGLY recommend that you (at least) have them do that FIRST, before topping up the system.
Edit: You also mentioned in your original post that they have installed a tracer dye. I'd also suggest that you have them do a black light test to see where the leaks are and repair them before doing the conversion to R134a (if that is what you plan to do.)

 

I got to looking at the reciept and couldn't figure some things out. The charges listed are for, compressor, drier, o-rings, 2.25#s of r-12, a flush kit, and a dye kit. What exactly needed flushing if the compressor and drier were replaced? In 2000 why would you refill the system with r-12 when you were replacing all the parts that needed to be changed to convert to r-134. I called the shop and spoke with the manager and he said that the flush was for flushing out the lines and condensor core. He also said that it should have been converted to r134 but couldn't explain why there were no r134 fittings. He said I needed to talk to another guy that won't be back until next monday. I'm not real A/C savvy, but I think I smell a rat somewhere, not sure exactly where but I dont think that $350 compressor has been replaced. I'll take a closer look when I get home today. I agree with you 66gmc, it's not usually the way I do things. In fact I think I'll take your advice, get the gas tested and go from there. Doing it the cheap way always gets you in the end.

 

I got to looking at the reciept and couldn't figure some things out. The charges listed are for, compressor, drier, o-rings, 2.25#s of r-12, a flush kit, and a dye kit. What exactly needed flushing if the compressor and drier were replaced? In 2000 why would you refill the system with r-12 when you were replacing all the parts that needed to be changed to convert to r-134. I called the shop and spoke with the manager and he said that the flush was for flushing out the lines and condensor core. He also said that it should have been converted to r134 but couldn't explain why there were no r134 fittings. He said I needed to talk to another guy that won't be back until next monday. I'm not real A/C savvy, but I think I smell a rat somewhere, not sure exactly where but I dont think that $350 compressor has been replaced. I'll take a closer look when I get home today. I agree with you 66gmc, it's not usually the way I do things. In fact I think I'll take your advice, get the gas tested and go from there. Doing it the cheap way always gets you in the end.

As far as "smelling a rat" goes ... I can't comment on that, other than to say that perhaps that was the way your Dad wanted it done?

R134A IS less efficient than R12, so perhaps that may have influenced your Dad's decision not to retrofit?

Perhaps it was the cost of having to upgrade / replace components (eg evaporator) that was prohibitive. I can tell you that all sorts of information had changed suring that time period. Originally, it was suggested that all hoses needed to be replaced with barrier-type hoses for example ... but tests showed that the ester-based refrigerant oil was doing an adequate job of protecting the hose from the more caustic R134A.

 

My dad said he had no idea and told me to call the service place, he just wanted his ac fixed Well they fixed it, to the tune of $950. He has no idea about r-12, r-134, or r2d2 for that matter. I'll just go get it tested to find out what it is. I know the hoses were not replaced. Is there a flush made for the hoses and condensor?

 

My dad said he had no idea and told me to call the service place, he just wanted his ac fixed Well they fixed it, to the tune of $950. He has no idea about r-12, r-134, or r2d2 for that matter. I'll just go get it tested to find out what it is. I know the hoses were not replaced. Is there a flush made for the hoses and condensor?

Yes, they do make an A/C flush solvent ... and unfortunately A/C work IS expensive. Isn't it funny that very few cars in the '70's even had A/C, and now it's become a necessity?

I buy my parts at cost + 10%, and it still cost me about a grand (in 1993) to get the A/C working on my 1986 Tempo. That was in 1993 when R12 was a lot less expensive ... about $3.00 / lb. I was DRIVING the kids to Disneyland (from Alberta) in the middle of July ... and darn right the A/C was a necessity ... even if fixing it meant doubling the value of the Tempo!

"R2D2" ... that's a good one

 

One more thing.

A lot of shops are installing tracer dye in order to check for leaks ... hopefully FUTURE leaks.

Our shop used to pressure test the system using nitrogen to make sure there were no leaks before installing the refrigerant.