woldson Posted June 6, 2009 Share Posted June 6, 2009 So a long time ago I blew the freon on my 83zx. So now I'm going to pull the compressor and drain the oil and blow the system out. Bought a conversion kit for 134a. Seems straight forward. Have an electric fan in garage that I will put on a switch in the dash. My zx has an electric fan as primary so I need the fan for the ac's condenser. (this is how I lost my freon) Any tips are most welcome. Need to figure out a way to pressurize system with air to check for leaks, any other oil that may be needed to be drained etc.... Now the only reason I'm doing this is for my wife, she drives the car more than I and ya know......... Also it is easier to get a hold of the 134a then r12. One other thing, seems like some have figured out ways to improve 134a's performace in formulation, any truth? Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted June 6, 2009 Share Posted June 6, 2009 Just to let you know. My 76 factory A/C has been running R134a for the past 10 years. I have had no issues. I changed as many o-rings as I could reach in the unions to assure tight seals. I didn't even drain the compressor. My systam had been open for about three years prior to me replacing the evaporator, condenser, and dryer bottle. I added some of the recommended PAG oil that is compatible with r134a. Then I pulled a vacuum on it for a couple of hours. Turned off the pump to make sure it held the vacuum. Then I charged it with about 75% R12 capacity of R134a. I had to customize the R12-r134a charge adapter that came with my K-Mart conversion kit. Quote Link to comment Share on other sites More sharing options...
trippintl0 Posted June 7, 2009 Share Posted June 7, 2009 Since the system is already flat, pull the evaporator and clean it really good and replace the weatherstripping around it. Clean & degrease the condenser coil (or replace it). Since R134a runs higher pressures for same temp as R12, keeping the condenser clean and possibly adding an extra fan will help keep the high-side pressure from being too high. Since you're disconnecting everything, replace any O-Rings. If you really want to try to make it leak free, replace those old A/C hoses with some fresh hoses designed for R134a. Finally replace the drier before you evacuate and recharge it. As far as retro-fits go, I always heard to drain the R12 mineral oil and use Ester oil. Although Ester oil is not as good a lubricant as PAG oil, I think you only use PAG oil on a completely clean system - there cannot be any trace of other refrigerant oil..but this is just from my memory, may not be accurate.. Quote Link to comment Share on other sites More sharing options...
AK-Z Posted June 7, 2009 Share Posted June 7, 2009 use a compressor to blow/clean out the system. reattach the pump and use teflon tape on all the fitting. there should be a check valve on the passenger side (assuming you have a 280z. don't know on the zx). You can get a recharge can from any auto parts store, heck I saw a couple at fred meyers in the auto section. Just screw on the fitting on the check valve and press the button. It should come with a gauge on the can to see if its full. Quote Link to comment Share on other sites More sharing options...
SHO-Z Posted June 7, 2009 Share Posted June 7, 2009 I did a conversion from R12 to Freeze 12 on my 91 4runner, got it off of Ebay. Before every year had to add a can of R12, a year later it is still working an blowing cold air. Did not have to change anything, evacuated system, added a can of oil in kit and the Freeze 12. I am happy with the stuff. I just thought I would let everyone know of another way to go. Quote Link to comment Share on other sites More sharing options...
woldson Posted June 8, 2009 Author Share Posted June 8, 2009 Got it finished up yesterday morning. Just need to write the whole thing up. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted June 8, 2009 Share Posted June 8, 2009 Cool! Quote Link to comment Share on other sites More sharing options...
Ferrariferg Posted June 8, 2009 Share Posted June 8, 2009 What kit did you use? I bought one about a month of ago and only 1 of the fittings worked and I couldn't get it to charge at all because the fitting was stuck open and kept evacuating itself. Highly annoying. I would really like AC this year. Quote Link to comment Share on other sites More sharing options...
trippintl0 Posted June 8, 2009 Share Posted June 8, 2009 "and use teflon tape on all the fitting." Depends on which type of fittings you are referring to: Flare fittings seal from the flare, not the threads. O-Ring fittings seal from the O-Rings, not the threads. If you are talking about the little adaptors that allow the R134a quick-connect hoses to be attached, then yes I agree, I believe those are supposed to have some kind of thread sealant on them. I would recommend putting A/C oil on any O-Rings to lubricate them prior to installation. And if your flare fittings are leaking, unfortunately you must cut if off and re-flare it. I don't know of any connections on the A/C system that use threads to seal,, unless it is some kind of pressure switch on the drier or something or the aforementioned adaptors. I suppose if your system leaks and you don't have to time or $$ to try to fix it properly, teflon tape on the threads may also slow down a potential leak. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted June 9, 2009 Share Posted June 9, 2009 I mentioned earlier, the adapter that came in my conversion kit needed modification. If I screwed the adapter on far enough for the o-ring to seat, the pin would hold open and the system would evacuate. I had to drill/cut/file to make the aluminum adapter work. I'll try to get a pic of it. The adapter was from a walmart or kmart boxed conversion kit. Quote Link to comment Share on other sites More sharing options...
Ferrariferg Posted June 9, 2009 Share Posted June 9, 2009 Thats the same problem I'm having. I put the fitting on and put in the supplied oil and then went to charge it and it only took about half the bottle and when I took it off, it just started spraying everywhere. Not cool. Knowing how to make it work would be great. Quote Link to comment Share on other sites More sharing options...
trippintl0 Posted June 9, 2009 Share Posted June 9, 2009 Just so you know, most of those R-12 to R-134a adapters require that you remove the Schrader valve stem out of the original fitting before screwing on the adapter. They usually come with a valve stem remover. If it doesn't come with it you can get them cheap, the ones for tires usually fit the A/C valve stems as well. If you try to screw on the adaptors before removing the old valve stem it usually won't go on correctly or it will hold the valve open or something weird. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted June 9, 2009 Share Posted June 9, 2009 Ahh maybe that's the issue. I don't leave my adapter in place. I remove it after the charge. I know that's kind of a no-no but I guess that's why my adapter didn't work right. Quote Link to comment Share on other sites More sharing options...
woldson Posted June 9, 2009 Author Share Posted June 9, 2009 My mom's subie will work a bit then stop. So I was at WAL Fart and saw a conversion kit for 34 bucks, 3 cans with oil mixed in and gauge, so I got it. The adapter screwed into the low pressure side, (can screw on to high pressure side as well), and had a sealant on the threads. Low pressure side is NOT the side that comes off the condenser. At least this is what I've came to understand. My zx has 86k on it and was stored properly before I got it. The O rings on the compressor were in fantastic shape so I did not want to break a bunch of seals that may be fine. I did lightly grease the o rings before reinstalling compressor. (ya know help to fight micro abrasions). Installed a 16in fan on condenser and wired it to a switch by the stereo, then reasoned that there is a switch in the atmosphere controls that engages the clutch, so I took that apart, found the switch, followed the wires past the plug and intercepted them and put them on a switch next to the fan switch. Main reason for this is that I did not want anyone activating the system without the condenser fan running! Added benefit I CAN RUN ALL THE DIFFERENT OPTIONS ON MY ATMOSPHERE CONTROLS!!! This is nice for the winter running the defrost and heat at the same time with the a/c! Had to use that yesterday, worked fantabluless! So only hitch so far, after second can of 134a the gauge was on the line of blue to green and the system was blowing cold air. After the third can the result was the same...... Did not want to get another, and, did not want to overcharge the system, so I left it. Ran the car hard Sunday seems to be working nicely. The big test is when it gets into the 90s. Seems like the system dose not take a "break" like the newer systems. Especially getting on it, the system will blow VERY cold, otherwise works better then I suspected. I will post up some pics later. I put on a econo belt for now because I did not want to get a gator if the system was not going to work. Now the system "blew" due to a lack of a condenser fan, (mech fan long gone for engine), the guy a smucks told me the is not a pressure release valve. He seems to be wrong due to the system holding pressure form the get go. My guess is that it is at the collector (accumulator?). If I have a small leak, time will tell, them I will have to take it in, possibly, due how slow it is. I guess I could use some soapy water. Will see. One last thing, I did not use teflon tape, or my favorite, pipe dope, due to the fact these are not tappered sealing threads. The o rings are the seal. Quote Link to comment Share on other sites More sharing options...
woldson Posted June 9, 2009 Author Share Posted June 9, 2009 Hey at least I did a Mod on the car, just not fix exitsting. My wife loves the "cool" switches. Still wish it was something that made the car faster, not slow it down......... Quote Link to comment Share on other sites More sharing options...
nismopick Posted July 31, 2009 Share Posted July 31, 2009 Bump on this... woldson, how's the a/c system running? I've been doing research for months on R12 replacements (Freeze 12, propane, R134A, etc). Many people say you HAVE to replace the evaporator, and you MUST change the o-rings, but I can't find anyone saying anything about their R134a conversion after they have done it (minus this thread). Quote Link to comment Share on other sites More sharing options...
woldson Posted July 31, 2009 Author Share Posted July 31, 2009 Like a champ! Talk about loss in power though,,,,,puke! Look, this stuff is suppose to be ev friendly, soo if I develop a leak due to the refrigerant, I will handle it at that time. The cost, if you have a mech fan, is soo cheap, you really have nothing to loose! In traffic, up to 90 and holding temp well. I do have a 195 thermostat in there, so this may make a difference. The reason I have gathered for the evap condensor, etc is due to the oil. I did not want to break seals on every thing just to get the oil out. When I researched it on the net, most said do this or that, but most did not and never had a problem, go figure. Quote Link to comment Share on other sites More sharing options...
nismopick Posted August 3, 2009 Share Posted August 3, 2009 What oil did you use? Did you pull the oil through w/ vacuum? I'd love to do the same thing you did and have working a/c again! Quote Link to comment Share on other sites More sharing options...
woldson Posted August 4, 2009 Author Share Posted August 4, 2009 Ok the days have been around 100, stop and go have not really been a problem. The car will run about 2/3 on engine. Stoping to get something I leave the fan running which help cool things while sitting parked. Blows quite cold, with t-tops the sun more directly on me, I'm still warm, but it is hot as you know what. With the system off, huge difference. Now I was at shucks, and they have some stuff that you can shoot through the system to clean out the old system of it oil. Did not really have the time to read the directions. I used, from empty of refergerent, r134a with oil. Remember I at least pulled the compressor and cleaned it as much as possible. Maybe next year I will drain it and clean more oil out of the system, or not, will see. Filling the system was painfully slow. I'll get the pics today. Call me if you want, 5094876988. Quote Link to comment Share on other sites More sharing options...
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