357

I recently took my '84 GS to a mechanic, already knowing that the AC unit was in need of a recharge, and he informed me that there were two options: First, pay $70 a pound for 3 pounds of R-12, or second, buy a $200 conversion kit and 3 pounds of R-134a at $8 a pound. This is all assuming the compressor still works. Now, I've already resigned myself to living without AC for the rest of the summer, because I won't be home much, but I still need your ideas on what I should do, and even if this guy is giving me a fair estimate for costs. All the help you could give me would be great!

Spieder

Well, you mechanic should be able to check the compressor. The only real thing that goes wrong with them is the seals which allows them to leak out the freon. I had mine checked for 30 bucks.

I just converted my RX-7 today actually to R134a so I know exactly what your going to have to do.
Here's my cost:
Rebuilt compressor $200, came with the manifold orings, but it depends on if you have the high or low compressor. Mine was on top of engine bay is factory. The dealers use a low sittign compressor that they installed.
Reciever/drier $30, came with it's own Orings.
New R134a compatible Orings for the lines into the compressor $2 (make sure they are green. The R12 Orings will dissolve with R134a)

$117 Labor to evacuate, flush with solvent, add necessary oil, pressure test for 45 minutes, change the fitting on my compressor to R134 fittings.

If you change your fittings yourself, they run 10 to 20 bucks and just screw on top of the old ones. But they are permanent.

So cost me about 350 bucks. And I can buy the R134 now at Kragens if I ever need to recharge the unit for 5 bucks a bottle.

You spend 210 for R12 and what happens when you have a leak. Gotta pay for 200 worth of freon again.

I can say the R134a works great. Unfortuneately, my rebuilt compressor is f***ed up and I need to take it back. The bearings are screwed up in it so it screams and howls. Luckily the guy isn't goign to charge me 120 bucks again because he can capture my existing stuff and hgold it for me in a tank. I guess he feels sorry for me, lol.

mwpayne

What about the $30 conversion kit at walmart? It says it has everything you need to convert it. Anyone tried that?

ddsmith

I used one of these on my 1987 Firebird. I read all the horror story about attacking seals and other problems associated with this conversion and just decided that I would use the kit and if necessary fix things later when they went bad. I'm still waiting for the later. It has been over a year and I've had no problems as discussed earlier. I do agree that to do it right would involve replacing the o-rings but that only part of the problem. The systems were designed with R-12 as the medium. Since you now want to run R-134a which has different characteristics you should look at replacing condenser and evaporator. This is one case were I will go with the it's good enough just to use the conversion kit for my car. It's your choice. I don't believe this will damage your compressor which is the big expense, so why not convert and do the test I am. Like I said later hasn't come yet.

Don

357

So, lemme get this straight. You had a drained A/C, that initially used R12, went out and bought a $30 conversion kit from Wal-Mart, put it in yourself, didn't have to replace any o-rings, bought the necessary amount of R134a (did you have to have a permit?), and everything works fine?! Sounds like i need to look into this! How did the switch go? Any tricky steps I should know about? Thanks!

Spieder

The kits use a different lube than R134a's synthetic and R12's mineral oil. The kits only work on existing A/C's that work. If your A/C has air in it you must have it evact'd or it will burn up your compressor. You must also have the right amount of oil or the compressor will burn up. If you have a leaky compressor, the kits won't help. It will leak right back out.

cletus

R134a doesn't require a license. The $30 kit from walmart is a bit half-assed solution, but it actually works pretty decent. My boss does this all the time (seems like the man is always buying POS cars). He recommended changing the dryer at the same time. I did it in my 7 and it worked ok for a bit. I had some other problems though (bad relay and maybe something else electrical) and then I had a hose fail (cloud of freon everywhere). But I was only out the $30 instead of the $200. The actual procedure to do it is simple, but I didn't have any R12 left in mine at all.

mwpayne

The kit supposedly comes with the oil and coolant. Why should I change the dryer, although it seems a good idea.

MACH7

I need to add some R134a to my commuter car. I was out last night searching for a re-charge kit. What I am finding are solutions that range from R134a cans with a refill tube attached to refill tubes that sell without gauges to simple color gauges that have removable hoses (first test low side, then attach another tube to bottle of refrigerant) to kits that use the same gauge to test both high and low side (with a swap of tubes) and a 3rd tube for the refrigerant bottle) to a full manifold set with connections to the high and low side and the refrigerant. Anyway, now I do not know which solution I should purchase. Or just throw my hands up in the air and go to a garage and have it done professionally. Seems like there is considerable experience here with recharging your own a/c. What is the recommendation, (i.e. can with just a tube? Single color coded gauge with a hose that you swap? Or a full professional manifold setup (which seems to run from about $65 to $120)? How critical is it that you have an accurate pressure measure? The directions on the kits suggest just adding 1 can. Is that safe, e.g. what is the risk of adding too much? Would the color coded gauge that Walmart sells (which just tells you if you have too little to register a pressure or whether you have the approximate right pressure or whether you hooked it to the high side, since you now have way too much pressure) work OK? I do not want to create a greater problem nor do I want to set myself up as a a/c repair shop by investing in more expensive equipment than I will ever use enough to justify. Any suggestions would be greatly appreciated.

nimrodTT

Bassed on what you said I would suggest you just take your chances on the cheap gauge and the refill kit. If you want to do it right, make a friend who has the stuff and just borrow it. You'll need the manifold gauges and a vacuum pump to do it properly. But you can get away without either.

TheBigOne

http://srd.yahoo.com/goo/Converting+...603d65691ecc1/*http://motorcoachtraining.tripod.com/news01.htmhttp://srd.yahoo.com/goo/Converting+...news01.htm</a>

I did mine and it worked for a day or so then it stopped. I found this site

TheBigOne

disregard the yahoo link

TheBigOne

click http://motorcoachtraining.tripod.com/news01.htm

MIKE-P-28

iTrader: (1)

My R134a coversion kit consists of 2 adapters that go on the compressor so you can get r134a lines on it. Thats it nothing more nothing less. They are like $5 for both!

Whenever you do a recharge/change its a good idea to change the accumulator... Its like $20

357

Ok, I'm a little lost, here. I see things about the Wal-Mart kit, and things about what seems to be a conversion made out of seperately bought parts. what exactly is it necessary to replace to go to R-134a, and does the Wal-Mart kit include everything? Also, does anybody have instructions on how to do the conversion?

85RX7GS

iTrader: (1)

If you're all out of R-12 in your current setup, then go with the R-134a conversion - use the Wal-Mart kit. If you only need a little bit of R-12, then fill it up with some R-12. I'm proud to say that my factory air conditioner is still running R-12 and it blows ice cold.

ddsmith

I'll just comment on the kit I used. It consisted of a couple of cans of R-134a, a can of oil, fittings to adapt your original fittings and the hose to connect one can at a time to the compressor low side fitting. I purchased a low cost venturi vacuum pump from harbor freight which is currently in their catalog for $10. You hook this up to the low side and hook air up from a air compressor. The air flowing through the venturi draws a vacuum on the low side. They rate these to be able to draw at least 28.3" of vacuum. Anyone who knows A/C realize this is not low enough to remove moisture in your system. Meaning if the system was open then this pump probably won't cut it. This should be adequate to remove any R-12 in the system. I know this is not the right way to do this but the amount of R-12 you are releasing is minimal. When the system is drawn into a vacuum the R-12 boils/ turns to gas and is removed from the system. Then you can add the oil to break vacuum in the system and the cans of R-134a. The important part to any of this is to ensure no air enters the system. The way I recommend you accomplish this is to always purge the line with the new gas or oil being added. You can accomplish this by throttling open the valve that threads on top of the can and hooks up to the hose until you have some flow of gas/oil from the hose and then attach the end to the low side fitting. I did not get a gage set because I wasn't interested in spending the $90 for the gage set. Prices on these sets are now coming down and I plan on purchasing one in the future. I charged by feel. It can be a little difficult to do but it worked for me. The kits have directions for the change. I followed what I chose to and ignored the have the system evacuated by an authorized A/C repair facility. The big thing in this whole deal is do you want to be cool or would you rather run around with no cold air and not enough money to let someone else say they replaced all the orings/dryer/accumulator and etc. and then use the same kit you could use. Good luck on your A/C adventures.

Don

MIKE-P-28

iTrader: (1)

I think the wal mart kits comes with a lot of extra stuff. Not sure never went with it. I juts drove down the street to Automotive Inc. and bought to 90 degree fittings to go on the compressor, one for the hi side and one for the low side. I also got a new accumulator...

Now you just put the right angle fittings on the compressor, change out the accumulator, Id also recommend undoing the hose connections at every point and replacing the rubber O rings inside.

Pull the system down on a vacuum pump for about an hour or so. Release the vacuum pump and let her sit about 2 hours or so, if you are still holding a perfcet vacuum (means its not leaking) Fill her up with r134a compressor oil and r134a refridgerant.. Dad told me once (i think, this is what he said) the capacity of the system with r134a is 80% of the r12. r134a expands more or something. So take the total system capacity and multiply by .8 (80%) Fill it with that much,be sure to factor in the oil with the refrigerant so you dont overfill and blow a line or something...

If you turn out to need parts I got a complete system

SuperPhly

If you live near our southern neighbor, the land of the beans and tortilla's, you can just go down there and have "Beto" or "Juan" refill your car with heavy duty, tree killing, freon for like $20... it's 100% legal to do it too... drive your car in, drive your car out... US has a problem with the "installation" part, not the "running" part.

Vato