zgeezer Posted April 24, 2011 Share Posted April 24, 2011 Time to clean up and mount my 280z ac condenser . It has been collecting dust for 6 years and I have some questions. The evaporator will be Southern or Vintage.. still shopping. However, the 280 Z condenser bolts nicely into my 240z and I would like to use it. Is this condenser compatible with the newer ac fluids (Freon vs. 134a). I'm told I should pressure test to exceed 240#. Is this true? Freon has been run in this evaporator, what do I need to do prepare it for 134a Is this one of those situations where one would be better off dumping the older condenser and dropping the cash for a custom Vintage, Southern all AL unit? Thanks, G Quote Link to comment Share on other sites More sharing options...
KunoZ Posted April 25, 2011 Share Posted April 25, 2011 (edited) Freon, if you’re talking about R-12, is def compatible with R-134a. It's just the old mineral that it is not compatible with. Your condenser, evaporator, and the rest of the system are good for the use of R-134a, just that the condenser needs drained (if nothing comes out when tilted up its good) and the compressor. Also the accumulator or A/C drier needs replaced anytime the system is open. The only thing you need to really worry about when retro fitting old R-12 systems is the amount of R-134a you put in. Should be a label to how much refrigerant you should put in. When charging the system, the R134a charge will be 10% less than the R12 charge. As, for pressure testing the condenser it's really up to you. Depending on how well the condition of it, it should be checked. If it is badly dented, scourged, or cracked I would pressure test it. Some would just put it on and put a vacuum on the system with a vacuum pump or machine, just depends on you really. Your evaporator is good. If you feel the need to you can drain it, but wouldn’t think anything would really come out. Your best bet if you don’t know much about A/C systems is just have the shop do it. They have the equipment to do it right and it not all leak out. Just ask for them to put dye in it just in case the refrigerant leaks all out you can see where the leak comes from. Also it is illegal to work on any automotive A/C system without being ASE certified, but really who does get caught by the EPA?! LOL! FYI Im not trying to be rude in any way just a lot of people get misinformed or misinterpreted with Freon and R12. Freon is a brand of refrigerant made by DuPont and R12 is the old refrigerant that was essentially phased out. But in all regards I hope I helped. Good day! Edited April 25, 2011 by KunoZ Quote Link to comment Share on other sites More sharing options...
zgeezer Posted April 26, 2011 Author Share Posted April 26, 2011 Thanks for the response. The condenser is in excellent cosmetic shape: no dents or bent over fins. Think I'll just paint it and install it. GW Quote Link to comment Share on other sites More sharing options...
rejracer Posted May 2, 2011 Share Posted May 2, 2011 If you have not yet purchased the refrigerant, you might check into a product called duracool. It's also called 12-R (not R-12). In a nutshell, it's 1% more efficient than R-12, is compatible with all lubricants, and can be mixed with existing refrigerants. Note, it's not legal to mix them, but it won't do damage to the system if you do. It's also non-toxic. The downside to this is it's flammable, as it's a pure hydrocarbon, but it's auto-ignition temperature is higher than R134. http://www.duracool.com/ As Kunoz pointed out, it's the lubricants that are incompatible. You must ensure you get all of it out. Evaporator/condenser can be easily flushed. They are "compatible" with each other, but the R134A is not as efficient as the R12/12R is, so the system will not cool quite as good. How do these condensers compare to the Vintage Air units? http://www.ackits.com/merchant.mvc?Screen=CTGY&Store_Code=01&Category_Code=Parallel Accumulators are replaced if they have been in service with another refrigerant. One note on the charge levels, I always go by the gauges for the given ambient temp/humidity. Here is an example chart: http://www.ackits.com/aacf/ptchart.cfm If you don't have a vacuum pump, gauges, refrigerant, lubes, dyes, injectors, thermometers, barometer..... then I would take it to a shop. A/C work requires a lot of special tools. Build it with the best parts, then take it to a professional is some good advice! Quote Link to comment Share on other sites More sharing options...
Tony D Posted May 30, 2011 Share Posted May 30, 2011 " Also it is illegal to work on any automotive A/C system without being ASE certified, but really who does get caught by the EPA?! LOL!" ASE doesn't have squat to say about it...it's a federal license you require. Easily enough obtained.... And most of the gauges and items are available online easily enough as well. That in conjunction with the FSM and it's charging procedures will get you set. I worked in this line of work for several years predating the federal licensure requirements, so I have all the old R12 stuff...couple of adapters and knowing your pressures and you're set for R134 as well. I have to agree with the 12R, I recently recharged my Dually (like yesterday)---it was worth the shot for the price. It was either pull a vacuum and test it for leaks...and sacrifice a can to test positive pressure integrity before committing to the whole system charge (damn system takes 5.5#!!!) It was either put in 12R (there is another one out there that I know of as well) or go buy a new compressor and clean everything to do the R134 conversion. If you have a new EVAP and compressor, you may as well go with R134 IMO, but if you have more than one R12 car in the yard...keeping with an R12 substitute may well serve you into the future. All my Z's are R12, and so is the dually. If the dually had to go R134 then so be it...I would still have had 11 cans of R12 to take care of the Z's for years to come! The issue on pressure testing is really: how do you get a 240psi pressure source? Unless you make up your own A/C compressor air compressor (very popular overseas) there aren't too many things you can use to pressurize the thing to that point! Can't use O2 (BOOM!) and who's getting a SCUBA tank converter? A Hydro Test rig...I don't even know if they rent them any longer. Best bet for the 'test' is to draw a high vacuum on it and see if you loose it over a period of observation. A leak is a leak, and vacuum will tell you if you have a pinhole just as well as pumping it to working pressure or above. If you don't have the stuff....you're kinda relegated to having a shop do this for you if you're unwilling to buy the components yourself. Harbor Freight had a nice 2 stage vacuum pump on sale for $99 last week. It was the last step (since my kid crashed the air compressor and my air-powered vacuum pump can't be used now...) in doing the Dually. Ran the pump and evacuated it down....just fine! Now to see if it's up to pumping down a 30 gallon receiver to use as a vacuum bag reservoir for composite construction... These things all blend together after a while! Quote Link to comment Share on other sites More sharing options...
rejracer Posted June 21, 2011 Share Posted June 21, 2011 Pressure test? Use a welding tank and the proper regulator. Any welding gas mix will work, Argon, Co2/argon, or tri mix. No Oxy as Tony said. I am certified scuba for open water, altitude and nitrox. Even compressed air (~21% oxy) is safe. I would not try it with nitrox, which is up to 40% oxy. My dad's buddys have converted A/C compressors for air compressors. They run power tools off their jeeps. Also never play with oxygen in any concentration, it is a very unforgiving gas. Co2, and nitrogen give physical warning signs, no such luxury with oxygen. Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 2, 2011 Share Posted July 2, 2011 (edited) Been a month now and checked the Dually pressures today: still where they were, and now that it's over 100, it seems like the A/C is working even BETTER! Interior of the truck will get to 60F. Amazing. I am glad I had the time to charge it this year. The issues with the welding gasses is getting a two stage regulator which will have a gauge that goes high enough on the second stage! Most of the inert gas regs don't go that high, and have more emphasis on flow at lower pressures. I'll admit it was something I didn't think about, but what does that reg go to, and like the SCUBA tank adapter---who actually has one laying around??? Anybody doing refrige work will have a vacuum pump, and Harbor Freight sells them for $99. Cheaper than a good N2 gauge set, and practical down the road if you do need to recharge! Edited July 2, 2011 by Tony D Quote Link to comment Share on other sites More sharing options...
(goldfish) Posted July 5, 2011 Share Posted July 5, 2011 Vacuum works great for testing for leaks. If you want to do a structural test, use water or some less compressible fluid. Then when it fails the shrapnel doesn't fly as far. Quote Link to comment Share on other sites More sharing options...
Tony D Posted July 7, 2011 Share Posted July 7, 2011 Speaking of that...if you have a small porta-power you can generate these pressures via hydraulic action. Were you to have a dedicated, small hydro pump with very low capacity and a good gauge you could fill the cooler, lines, and pump with reefer oil, then pump away to hydrostatic pressure. Leaks could be easily identified with UV Dye (since most comp oil now has UV Tracers in it) and you simply flush it all out with Alcohol when you're done. Oil is cheap. So are porta-power heads in need of a seal kit! Just another alternative... Quote Link to comment Share on other sites More sharing options...
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