A/C Retrofit

Joined
May 11, 2004
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1,562
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St. Paul, MN
After driving to work today in 90 degree weather with 35mph wind gusts whipping dirt through the open window into my face, I decided to finally do something about the inop A/C on my car (92 Acura Legend) When I first bought the car in 04, it still had r-12 and the system worked great up until last spring. At that point I replaced a number of o-rings and re-charged with an r-12 direct drop in replacement (r-414b) It blew cold for a few months then the refrigerant charge leaked out. By then fall was approaching so I left it empty over the past winter. Today I finally broke down and retrofitted it to 134a. More specifically, I installed the Acura OEM retrofit kit, which included 134a service port fittings, a retrofit label, and a bottle of special retrofit PAG oil. Pulled the compressor out of the car, put the oil in, replaced a few more o-rings, put it back together and charged it with 134a and leak detection dye. From all I've read and heard, I wasn't expecting much at all. Lo and behold, on my drive home my probe thermometer is reading 36F coming from the center vent! The temp knob was even about two notches above full cold. Granted, this was at night with no sun load, but so far I'm impressed. Hoping the o-ring replacements take care of the elusive leak, if not I have the dye tracer to track em' down.
 
Joined
Apr 17, 2006
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Lake Forest, CA
Wow, 36F is cold. My '00 E430 could not get below 40F from the center vent the last few years. It was 37-38F the first few years, then it started to lost cold air for some reason, even after recharged with R134a every other year.
 
Joined
Dec 21, 2003
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Northern CA
Kewl, except with 36F air you are close to building up ice on your evaporator. If it gets weak after it's been run a while, check for that. That performance is impressive. \:\!
 
Joined
Feb 4, 2007
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kansastan
That IS impressive- you usually don't get that kind of performance out of a retrofit. About the leak: I've never touched an Acura- unless you count one that I ran a truck into once. But having worked on lots of a/c systems... I'd suggest that you look at the compressor shaft seal. If the clutch is easy to remove (and lots of them are), pull it out and have a look. If you see oil buildup around the shaft, then you've likely found your leak.
 

AcuraTech

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Joined
May 11, 2004
Messages
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Location
St. Paul, MN
 Originally Posted By: onion
That IS impressive- you usually don't get that kind of performance out of a retrofit. About the leak: I've never touched an Acura- unless you count one that I ran a truck into once. But having worked on lots of a/c systems... I'd suggest that you look at the compressor shaft seal. If the clutch is easy to remove (and lots of them are), pull it out and have a look. If you see oil buildup around the shaft, then you've likely found your leak.
Actually I do see a bit of oil residue around that area, that will probably be my next project. Drove it again today (during the day with sun load) and still blowing icicles out of the vents. Amazing, really. I honestly thought it wouldn't work for ****, that's why I was reluctant to do it in the first place.
 
Joined
Jul 18, 2003
Messages
661
Location
Bosphoria
My exact experience with another old r12 system. I was postponing the mintenance in the hopes to find some r12 and after one humid week I decided to have it charged with r134 whatever the mechanical consequences. Well, the spec. is 4°C and it blowed 2°C ! But I still think it had more capacity with the proper designation, it used to feel less humid and healtier before, cooling the overall interior somewhat better. Unlike the r12 that never needed charge mine kept decharging yearly with the r134 afterwards. With such an old system it is time for dryer replacement and if it keeps decharging you may want to consider a barrier type rubber refrigerant hosing. Some oil around shaft considered normal with r12 compressors where the oil itself works as a barrier. I think these are some of the reasons why they specs heavier PAGs for conversions. There are also variable or straight orifice tubes optimized for r134 but some think they are a marketing ploy. I haven't done the changes yet, just wrote down my findings in search for a better conversion.
 
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