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This may be a dumb question to some but just bought an 85 SS with [non-working] factory air. I'm mechanically capable but have no technical experience with A/C systems.

I'm now using the car as my daily driver (commute of about an hour each way). Summer's beach traffic is coming so I'm going to want the air to work well.

I believe the refrigerant is probably R-12? If so, what's the recommended approach to recharging it?

Would you just recharge with R12 (assuming I can find some)?

Or should I convert it to R134a? If so, who's done this? What's involved and what are the drawbacks or pitfalls?

Thanks!
 

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First you need to know that it being low on charge is the problem. Next you can get 12 but it's not cheap so you'd want to know how bad and where the leak is.
Donny
 

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First thing you need to do is have your system vacuum tested to see if it holds pressure. If it does, that's a good indication you have no major leak. Then I would do a 134 conversion. I have seen some kits that include an instructional DVD. Its really not that difficult.
If you have a leak, that needs to be addressed, and then convert to 134. R12 money is out of the ballpark, so go with the 134.
Also note, if your underhood AC decal says the system holds 2 1/2 lbs., the amount of 134 will be slightly less. I don't remember the formula, but that info might be in the retro-fit kit.
 

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Check under air conditioning I have post of my experience. I recharged mine with m-12 and the compressor shaft froze. If you have r-12 and switch 134 you may have a problem with it leaking out the rubber hoses. Darbysan-Mike walked we through a complete under the hood replacement and once I started the project and taking my time to do it right with 134 the air is to cold on high and perfect on low. Cost with all the misc. crap was about $700.00 and worth every penny. Once you start changing one thing after another you will end up spending more on recharging the system. Get the Freon at Wal Mart don't buy name brand your just wasting your money $19.00 or lower per can. I even listed all the parts somewhere in the a/c forum.
Robert
 

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you can convert to 134 the proper way is to replace all o rings with the new green rings and replace the hose manifold set comeing from the compressor.the 134 systems use a barrier hose to prevent leaks.you will need to clean the system of all the old oil.change the drier assembly and flush the compressor.replace the orifice tube.deep evacuate for at least 45 min. then charge.another option is freeze 12 it is a r12 replacement that works very well and is a lot cheaper than r12.if you replace the compressor all new rebuilds come compatible with the new refrigerants.
 

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you can convert to 134 the proper way is to replace all o rings with the new green rings and replace the hose manifold set comeing from the compressor.the 134 systems use a barrier hose to prevent leaks.you will need to clean the system of all the old oil.change the drier assembly and flush the compressor.replace the orifice tube.deep evacuate for at least 45 min. then charge.another option is freeze 12 it is a r12 replacement that works very well and is a lot cheaper than r12.if you replace the compressor all new rebuilds come compatible with the new refrigerants.
I used the freeze-12 and was warned about the compressor freezing up but didn't take their advise and my compressor froze. It blew ice cold for a couple of weeks.
 

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I found a reasonable source for R134a, if you don't mind buying a case. I went through several charges over the last 3 years, so I wish I had gone this route initially. I've used this R134 on my Elky, on a Volvo, and in my wife's Avalon. So far, no issues. $60 /case of 12 including shipping ( no tax, at least for my state).

http://www.r-134a.com

IIRC, it takes about 43 oz of R134. Each can holds 12 oz, but you can't get is all out ( i figure 1 oz lost to residual in can, flushing the line with each can changes, and any loss on tapping). I use 4 cans on the Elky, and it's just about right. Pressures are a little low on the high side ( maybe could use a little more) but I'm getting 40 degree air out the vent.


I'll wait for 100 degree weather to see if I need just a little more. By the way- too much is just as bad as too little. It's a fine line on R134a- best to fill by weight if at all possible.
 

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i have used freeze 12 for years and never had any compressor issues.useing freeze 12 you have to use the oil for the 134 to properly lube the compressor. compressor failure is almost always due to poor lubrication or improper lube choice or overcharging the system.freeze 12 has been out since they banned private non licensed sale of r12 in the 80s. if it killed compressors it wouldnt have been around this long. you cant cut corners when converting an ac system. or you will have problems.do it right and you will be happy which ever way you go. you scale in the correct charge of oil and freon and it should live. freeze 12 and 134 both take less freon than the r12 required fill.
 

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I'm sure that was my problem plus the system was twenty seven years old. I sure got my money out of it. And thanks again Mike I'm still blowing ice cubes. Mine took 4-cans also and it's just right.
:You_Rock:
 

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I found a reasonable source for R134a, if you don't mind buying a case. I went through several charges over the last 3 years, so I wish I had gone this route initially. I've used this R134 on my Elky, on a Volvo, and in my wife's Avalon. So far, no issues. $60 /case of 12 including shipping ( no tax, at least for my state).

http://www.r-134a.com

IIRC, it takes about 43 oz of R134. Each can holds 12 oz, but you can't get is all out ( i figure 1 oz lost to residual in can, flushing the line with each can changes, and any loss on tapping). I use 4 cans on the Elky, and it's just about right. Pressures are a little low on the high side ( maybe could use a little more) but I'm getting 40 degree air out the vent.


I'll wait for 100 degree weather to see if I need just a little more. By the way- too much is just as bad as too little. It's a fine line on R134a- best to fill by weight if at all possible.
That's a deal. Thanks for the tip. :nanawrench:
 

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134 pressure are generally low compared to r12.look more for a good pressure diferencial than a high high side pressure.as long as your schrader valve is good you shoul get cold air
 

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I actually thought the R134 pressures went higher, hence the need for the high pressure cut-off switch in the compressor. Anyway, what I look for is high pressures about 2.2 to 2.5 times the ambient temperature. Make sure the engine fan is running if it is electric. Airflow across the radiator will dramatically reduce the pressures. Also turn on the AC to Max Cool and put the fan at least to Med. use a Temp Probe to measure the Temp at the center vent. 40-42F is pretty good. You can also measure the temp of the two pipes as they come out of the evaporator under the hood ( non-contact Laser Thermometer works pretty good here). The temps should be about the same.
 
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