Dave@Moon Posted July 26, 2000 Share Posted July 26, 2000 O.K., here's the story. I bit the bullet on my wife's car and converted it over to R-134a. The a/c system leaked and I obviously couldn't add R-12 anymore. Since it leaked out, I never bothered to convert it and it sat unused for 2 years. <P>Then I discovered that Interdynamics sold R-134a Stop-Leak in addition to the conversion kits. I put it in as per the instructions, and it worked perfectly <I> until.... </I> <P>Three days of use later, the compressor clutch is slipping and squealing loudly. The car had no such symptoms before. I've had at least one informed opinion that the stop leak clogged the lines and the compressor can't fight it. I noticed after the car is shut off that the compressor "creeps" forward about 1/64th of a turn 2 or 3 times, slipping the clutch.<P>It still blows cold air, in spite of the problem. <P>Is it a bad clutch, or did I clog the lines? I don't want to drop the coin for a new compressor or clutch assembly if it's going to do the same thing. Has anyone else used this stuff? I wondered how you could clog a leak in the lines w/o clogging the oriface tube, but apparantly it's not yet clogged because it's still blowing cold air. <P>Anybody want to buy a used car? <p>[This message has been edited by Dave@Moon (edited 07-26-2000).] Link to comment Share on other sites More sharing options...
Dave@Moon Posted July 27, 2000 Author Share Posted July 27, 2000 The oil most definately went in. In fact between the 2 12 oz. cans and the 3 oz. w/ the oil, I had exactly the 27 oz. I needed. I then added the stop leak, and everything was hunky-dory for about 2 hours running time. <P>The car's a 1990 Dodge Spirit. I know, but for what I paid for this thing 6 years ago w/ 28K miles on it you would of bought it too! <p>[This message has been edited by Dave@Moon (edited 07-26-2000).] Link to comment Share on other sites More sharing options...
Guest Posted July 27, 2000 Share Posted July 27, 2000 I've converted a couple over. I hope you remembered the oil! You didn't say what kind of car, but on some you will need a High pressure cutoff switch. Some have them, some dont. Trust me I didn't know this at first. It sounds like the problem is more related to the sitting unused for 2 years than the R134a, although I wouldn't rule out the stop leak. Most leaks are in the condesor, that's what I had to replace once.<P>------------------<BR>-Keith<BR>'87 Lesabre T-type (The T without WHOOSH)<BR>http://members.xoom.com/lesabrettype Link to comment Share on other sites More sharing options...
Guest Posted July 28, 2000 Share Posted July 28, 2000 Dave,<BR>I'm not an A/C expert, but am in the process of "undoing" an R134a conversion on one of my cars. Here is what I've learned talking to technicians and A/C engineers at General Motors.....<P>If you remember nothing else, remember that when it comes to "old" cars, R134a is BAD. Repeat after me, "BAD". This is with regards to any vehicle not designed to be used with R134a (most cars before about 1993-4). <P>1. R134a is NOT compatible with mineral oil that is used in R12 systems. It requires a synthetic oil called PAG. PAG oil is BAD-BAD-BAD on compressors. It's a lame-assed lubricant. As a result, any compressor not designed to live with R134a (and thus, PAG oil) will have an EXTREMELY short life.<P>2. Those "$39.95 Kits" at the auto store are the worst thing you can use. They do not instruct you to completely drain the mineral oil out of the system. Because PAG oil is totally incompatible with mineral oil, the "kits" use an Ester oil. Unlike PAG oil, Ester oil is compatible with both mineral oil and the new R134a, but is only slightly better than spit as a lubricant and therefore KILLS compressor life. Also, because the new Ester oil charge (8 oz with most "Kits") is in addition to the full mineral oil charge already in the system, there is now an excess of oil in the system. This compromises the already weak cooling ability of R134a.<P>3. The R134a is a smaller molecule, and will leak out of the system easier than R12. It is also harder to detect with leak detector tools, since the leaks are often smaller and more numerous.<P>4. Unless you replace ALL rubber hoses with the newer "barrier" type construction, the refrigerant will leak and the hoses will be eaten from the inside by the PAG oils. Ditto for every single O-ring seal in the system. If you doubt this, look at any car that is equipped with R134a from the factory. They all have barrier hoses that have premium cost associated with them. And you know the auto companies won't put premium cost in something like a hose unless it's absolutely necessary.<P>5. If you are able to surmount all previously mentioned problems, you are left with the simple fact that R134a won't cool as well. Don't get me wrong--in a system DESIGNED for it, the R134a will cool fine. However, it operates at different pressures (higher) and generally has different properties. To make an "old" system cool efficiently with R134a, the entire system would need to be modified. I mean different orifices, revised pressure switch thresholds, etc. Of course, this is not practical at all.<P>Well, sorry for all the gloomy news. They didn't mention any of this on the side of the "Kit", did they? Does this make you wonder about switching back to R12? Well, good thought, but.....<P>To switch BACK to R12, all traces of PAG oil, Ester oil, and R134a must be removed. The dehydrator (or accumulator--which ever you have that holds the desicant) must be changed because the desicant holds residual oil that cannot be removed. All lines must be disconnected and flushed, as well as the condenser and evaporator. Doesn't sound too bad? The "zinger" is that the compressor SHOULD be replaced. You can drain it all day and you won't get every drop of oil out. Some folks re-use it, but remember that after running with PAG or Ester oil, it's probably half shot anyways! <P>Bottom line for all you guys with R12 systems that are thinking of changing to R134a is: DON'T!!!! Contrary to common opinion, R12 is STILL AVAILABLE. Sure it's not manufactured any more (at least not in this country--but that's another story), but there is still a large supply. It is, however, VERY expensive and you must have a license to buy it. Here in Michigan, it's about $30 a 12oz can. However, when you consider the headaches and poor performance of a conversion, the cost of the refrigerant is inconsequential. So you save $75 on the cost of the freon (assuming a full charge is needed). You'll spend half that savings on the damn "Kit" and then 10 times that $75 to switch your system back!<P>By the way, an EXCELLENT site for A/C info is "http://www.aircondition.com/wwwboard/retrofitting/index.htm"<P>Good luck Dave!<P>Greg Link to comment Share on other sites More sharing options...
Dave@Moon Posted July 28, 2000 Author Share Posted July 28, 2000 Greg, I'm going to need more than luck. I tried to use the a/c 2 more times. It worked great the first time with minimal noise. The second time the noise was worse than ever and the compressor finally froze up. <P>p.s. The Interdynamics kit used ester oil. Link to comment Share on other sites More sharing options...
Don Caithness Posted July 28, 2000 Share Posted July 28, 2000 Dave,<BR>27 oz. of oil sounds like way too much. An A6 GM compressor uses 10-12 oz max. Drain off some of the oil before you crack the compressor wide open!!!! Link to comment Share on other sites More sharing options...
Dave@Moon Posted July 29, 2000 Author Share Posted July 29, 2000 Oops! Sorry Don, but thanks. That was 27 oz. of R-134a (=85% of R-12 capacity). I's done failed 'em grammer classes! Link to comment Share on other sites More sharing options...
Guest Posted July 29, 2000 Share Posted July 29, 2000 I hate to confuse you further, but I have something to add. I spoke with my dad, a forer heating A/C repairman. He mentioned that even a little moisture from water in the system can cause the problem you had. Was the system flushed out? He mentioned some other things, but I can't recall it all right now. I 'll check again and see what he said. Link to comment Share on other sites More sharing options...
Guest Posted July 31, 2000 Share Posted July 31, 2000 S/w my dad again. He advised me it is very important to have a vacuum pumped on the system before adding anything. Maybe you did this, but it wasn't mentioned. By the way, if some local parts store tries to tell you that you must buy a new accumulator to keep the new compressor from dying, it's B.S. All that thing is is a metal tube with a little cloth baggie in it. They will probably say that when the clutch died it could have left metal shavings in the system and in the accumulator. They will then say it could get into the new compressor clutch. The problem is the clutch is an external component and it cannot send shavings into the system. They will also want to charge 40 to 60 dollars for this tube and will not give a lifetime warranty on the compressor if you don't buy it. I say all this because I had to deal with a shady outfit here in Az. that tried this little number on me. They sold me a bad used compressor and then would not exhange it or return it without a big fight. Had I not known these things in advance I would be out some money. Link to comment Share on other sites More sharing options...
Guest Posted July 31, 2000 Share Posted July 31, 2000 Everybody ~ Thanks for all the information and insight on A/C in older cars. The A/C on my '55 Century Htp doesn't cool, and now I think I'll just leave it that way and open ALL the windows. Howard Link to comment Share on other sites More sharing options...
Guest Posted August 1, 2000 Share Posted August 1, 2000 Has anyone heard of a product called FREEZE 12? It is supposed to be a direct replacement<BR>for R12. Claims to be almost as efficent and requires no modifications to current system,<BR>use original hoses, seals, and oil and can be mixed with R12 but flushing is recomended.<BR>I would be intersted in trying it out as long as no one has ever heard of anything bad<BR>about it. Link to comment Share on other sites More sharing options...
Guest John Chapman Posted August 1, 2000 Share Posted August 1, 2000 Howard, Dave, Pat, et al:<P>Things I've learned the hard way:<BR>1. Have a pro hang the kitchen cabnets<BR>2. Have a pro do the brake work<BR>3. PAY the delivery charge, even if you own a pickup truck.<BR>4. Auto A/C systems involve black magic. Pay the excorcist.<P>I've been through all the misery in the above posts at one time or another. The best solution I've found is to ask the very best collision repair shops for recommendations for technicians. We have a number of freelancers out here that do collision repair/replacement work for the body shops and are very good and relatively inexpensive. My experience has been that most service shops and dealers are not good at A/C work... to wit:<BR><B>Ford</B>: Local garage took our '85 Crown Vic, and diagnosed A/C failure (stopped making cold air) as a failed compressor. Repair estimate was $500 plus. That'a s bit steep for a ten year old car, especially <I>that</I> ten year old car. <B>John's solution</B>: Run it to the body shop that just did a terrific job of replacing top and repairing interior. Their 'freelancer' fiddled with the system for 10 minutes, replaced the high pressure switch, added 2# of freon and charged me $47.00. I bought the man a cold soda, too.<BR><B>Mazda</B> Aftermarket A/C quit just after warranty expired (imagine that!). Funny thing was, the compressor would engage, but only when the fan was in med or high. In low, fan worked, compressor didn't engage. A/C shop diagnosed it as a switch on the compressor, and would gladly replace it for $250. Same solution. Freelancer came to the house, correctly diagnosed the problem as a faulty blower motor resistor. Despite three hours to disassemble the dash to get to the part and replace it, the cost was $120, and I didn't buy a $250 part that wasn't needed.<P>Life's too short to drive with the windows down in the summer time while freighting 200 pounds of disfuntional hardware.<P>Good luck!<BR>JMC<P>------------------<BR>John Chapman<BR>BCA 35894<BR> jmchapman@aol.com <BR><p>[This message has been edited by John Chapman (edited 08-01-2000).] Link to comment Share on other sites More sharing options...
Dave@Moon Posted August 1, 2000 Author Share Posted August 1, 2000 JPCDGT, not that I'm exactly the best guy to be giving a/c advice (obviously), but I've avoided all the R-12 replacements like the plague. All the one I've seen are flammable gases (usually propane-based). Just what you want under pressure in an old system under the hood with a running engine! Link to comment Share on other sites More sharing options...
Guest Posted August 2, 2000 Share Posted August 2, 2000 Wait a minute... is this the same Dave that said, and I quote, "I think Chrysler engines spin the right way, its their management that's constantly turning circles in the wrong direction!" ???<P>See what you get for dissin' the Mopar boys <P>JPCDGT: I've avoided all the R-12 replacements like the plague as well... I've heard horror stories about black market replacement kits ruining all the components, or worse. I wouldn't try it.<P>Matthew<BR> Link to comment Share on other sites More sharing options...
Guest Posted August 2, 2000 Share Posted August 2, 2000 Hey whats wrong with propane it is a perfectly good fuel for a car!Oh yeah were talkin about AC. But I have had lots of luck with propane as fuel. Been using it most of 13 years now. Anyway I'll have to ask my AC mechanic friend someday soon on the scoop on the proper way to convert a Mature carso some other AC system. Link to comment Share on other sites More sharing options...
Dave@Moon Posted August 3, 2000 Author Share Posted August 3, 2000 Sorry 67GS, this one's a Mitsubishi in Mopar clothing! But we won't hold that against it, will we??? <P><p>[This message has been edited by Dave@Moon (edited 08-02-2000).] Link to comment Share on other sites More sharing options...
Guest Posted August 6, 2000 Share Posted August 6, 2000 Check out this link for more info: <A HREF="http://www.epa.gov/ozone/title6/609/choice.html" TARGET=_blank>http://www.epa.gov/ozone/title6/609/choice.html</A> Link to comment Share on other sites More sharing options...
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