R-134A installation I have read and been told by techs that You can use the old hoses with 134a if the R12 system was lubricated with mineral oil which it likely was. The older hoses become "sealed" with the mineral oil not allowing the smaller 134 molecules to permeate the hose walls. If you are replacing any hoses and converting to the 134a you must use a barrier type of A/C hose. I just did this on my 74. I replaced the compressor and dryer, a couple of O rings at the in line fittings. Evacuated, leak dye tested and recharged. Everything cost $325.00 and I paid a guy to do the charging. Was nice and cold. Paul Katson RQ-B 2431 July 2001 --------------- I too have heard that if the R12 hoses are in very good shape, don't leak and are coated with the mineral oil, you do not have to replace the hoses. Don Lindner and I have both converted several systems without changing the hoses, and all are working very good. On my 63 R1 Avanti, about five years ago, I installed the factory AC on it, using a newly rebuilt York compressor, all new barrier type hoses, and a new receiver/dryer. The system performs very well..... on the trip to the AOAI meet in Georgia, and then down to south Florida and back... 1200+ miles each way, I used the AC for some of the time and it always cooled down to 40- degrees at the vents. Around town, it gets too cold in the car, but on the highway, having to contend with too much engine heat coming up through the floor and transmission tunnel, the blower really needs to be replace with one that blows harder.... and I also need to add the factory fresh air flow into the transmission tunnel...... But that's another story...:) Lew ---------- the only thing you have to do to convert is, evacuate the system, give it 4 ounces of ester oil and charge it with 134a. I've done a ton of them like that and never had a comeback. Chip Dec 2001 ------------ remove the evaporator core from the box and send it off to have a new one made with "O" ring ends on it IF it has flare ends. 134 doesn't like flare fittings. Classic Auto Air in Tampa or Vintage Air in Texas can do the job. If you already have "O" ring ends on the evaporator, then you are...or will be..cool. Studebaker George ---------------------------------- I have used 134 with several original Studebaker evaporators, and a couple old Mark IV's- with no modifications at all. Flare fittings don't leak either- provided they are in good shape. ------------------------------ The Freeze 12 has been the answer for me. I cant tell any difference in it and the R-12, just been putting it on top of R-12 and not changing a thing. It will be interesting as to how it works for you. ___________________________ Freeze12 is a blend! made up of left in the bottom of the good stuff, and things added to it so you get cool air out of the vents. When the stuff added leaks out and not the other stuff, what do you top off with? How much of what leaked out? What is it doing to your compressor and other parts? They tell you just what you want to hear. That is the only why they can sell it. And I still think 134A can be bought cheaper than and Blend. MY 2 cents and I work with refrigerants every day all year long, and have run test on blends. If blends where haft the price of 134A I still would not use it. Ebon... _______________________ Convert it to 134a. You have to change the fittings and lubricant. It is cheap unless your hoses are bad which usually is not the case. The QUESTION IS: Does 134a work as well as R-12? I have been told yes and no. No one seems to have the answer. 29 _________________- Is it a seal issue? I had a local guy tell me that he could retro 134a no problem in my car (VW, but uses a similar compressor to a Stude) but I don't trust everything he says (he said I didn't have to replace drier either)` _________________________- I am not an AC expert on roubleshooting, but here is what I have learned so far from shopmanuals, repair guides, and instruction manuals... The 134 does not work as well as the traditional R12 At higher temps, the cooling fades away some. The condenser is supposed to be enlarged 25 to 30 percent to help make up for R134's Lesser capacity. The expansion valve is supposed to be changed to one with different calibration because of the 134's different temp/pressure/vaporization from the old R12, but nobody ever changes that. They don't concern themselves with the reduced effectiveness, and are glad it blows cold air again. I have been asked to put in a few of those Wal Mart / AutoZone change kits in previously working ACs. Most of the time it works fine, but twice it didn't. Don't knw why. I hink it was the older Mopar calibration on the temp/expvalve controls. It would only cool a little then act as if it was responding to a control telling it that it was cool enough... One hint- Put in the new oil as soon as you can to avoid compressr damage. The kit said to put in some 134 THEN the oil. If you don't get to the oil part of the instructions quickly the compressor can get damaged. The insructions do not tell you that part. They just say add 134, Then add the oil. The old oil remnants in the system do not seem to be very effective with the 134 circulating. get the changeover oil in quickly. R134 has a much smaller molecule than R12, so it can seep thru the "traditional" hoses. Common thinking is that the older hoses that have seen use will be "sealed" somewhat by the old oil in the rubber pores, and therefore do not need changing. R134 will still seep thru, but supposedly at acceptable levels. The "blends" will be a mix of different gasses. When you need to "top it off", some of the blend will be gone, and most of the remains will be a relatively useless mix of "other" gasses. To get it to work again, the "leftovers" will have to be removed to make room for the blend that actually works. Pumping it down also is important to remove the inevitable air infiltration that sometimes happens when freon is checked or topped off. An AC with a low charge can go into vacuum on the low side when you run it to check it. That can also introduce air with deadly moisture. The tiny moisture in the air will become acid that will have your AC eaten up from the inside in no time. A small amount of air can rob you of cooling and even freeze up the expansion valve from the inside. Small amounts of air is what will cause the "sand" inside he system from fast corrosion eating up your parts. A while back I donated an AC vacuum pump to the NG tool loan program. It should still be around somewhere.... I think I donated it at the same time someone else was donating one, so there may be two available for loan...? D L __________________________ R134 conversions can be simple or expensive - some just change the oil and pump in the R134 -= others do it 'by the book" and change O-ring, receiver dryer and the expansion valve - I also change the compressor - so the quote from different shops can vary as much as the variety of operations/equipment. The compressor runs at a higher pressure (read - shorter life) and the output is 10 degrees cooler, and it takes longer to get cold - living in AZ - the 10 degrees is a factor for sure. If it is working OK as is - why convert? -- wait until something breaks - then the differential in refrigerant cost will make it more palatable!! ---------- I am a licensed tech on home refrigerators and have used both R12 and a blend (not R406A which I believe to be comparable) but R401A which is another competitive drop in substitute for R12 for several yeards. ALso have used it in vehicles. BUT, as a blend of different gases of different volatility, IF you have a leak and try top 'top it up' you will end up with a blend of non-original percentages of the component gases because the most volatile will leak out faster than the less volatile. You probably could top up once or twice, but after that would need to start with an empty system, vacuum-pumped and then recharged from scratch. At about $6/lb. the cost is about 1/4 that of R12 which is getting much harder to obtain also, since it hasn't been manufactured in the US for about 7 years. BUT probably no shop will use it in your car so it only will be useful to you if you can get certified and do it yourself. R134a is readily available, not expensive, but does require removal of old oil, recharge with the correct oil, a change of the filter-dryer, and conversion to one-time adapted charging ports. In order of efficiency the blends are first, R12 second, and R134a least, so if you don't change the condenser to a larger one (tricky on our cars), you will lose some percentage of your cooling capacity--maybe OK in northlands, but in Tucson that would be a bad thing. Good Luck to all. Dave '78 RQB 2670 (in Black). ------------ June 2005 I replaced everything but the evaporator in my 82' about a year and a half ago with components from Vintage Air. They were all R-134a specific except the thermostat. Of course, with the stock / modified argument sure to pop up, I will only say that it is 97 degrees in the Chicago area today and the vent temp (measured with a digital refrig. thermomoter) is 39 degrees at idle and 34 degrees at highway speeds. I wanted COLD, efficient AC NOT stock components. Vintage Air is a GREAT source of info. and assistance and their catalog explains basic AC theory in plain english as well as dispelling a few R-134a myths. For one thing, R-134a is a MORE efficient mover of heat energy than R- 12. With this and the fact that R-134a is friendlier, cheaper, and more redially available in mind (if your choice is effctive, reliable cooling) here are the facts: 1. The compressor size dramatically affects performance and bigger is NOT always better. It will be R- 134a specific due to the seals and internal components having to be compatible with the R-134a oil and higher operating pressures vs. R- 12 systems. 2. The condenser is probably the single biggest factor in how well the system works. Modern R-134a systems use a "parallel flow" design that allows far more heat transfer in the same or smaller area than the old (stock) "fin & tube" models. The "parallel flow" portion of that description refers to the fact that the refrigerant passes through multiple passages in each tube giving it greater contact with the surface of the condenser and, therefore, more heat transfer. 3. The hose used for R-134a is different than that which was used for R-12. It is referred to as "barrier" hose due to a membrane sandwiched between the layers of EPDM (rubber) to block the flow of the smaller R-134a molecules (vs R-12)out of the hose walls (this is why so many "converted" systems seem to leak with no obvious source). Even the fittings and crimping method are specific to R-134a hose. They are known as "bead lock" fittings and should ONLY be crimped parallel to their circumference NOT their length. 4. The expansion valve is R-134a specific and is located at the evaporator inlet under the dash. 5. The receiver/drier contains a dessicant (spelling?) that is also R-134a specific. 6. The evaporator is NOT R-134a specific and needs only to be flushed / cleaned and checked for leaks. I know all of this sounds daunting but I assure you it is surprisingly simple. AC components in an Avanti were nothing more than an aftermarket or "hang on" system that was cosmetically altered to appear integrated. As a result, every component is very common, does not (with the exception of the compressor which is about 1/3rd the size od stock, about 10 pounds lighter, and FAR more efficient) look "different", and not really THAT expensive. I replaced EVERYTHING but the evaporator, had IT flushed / leak tested, and new fittings brazed on to accomodate "o- ring" fittings, and had it evacuated / charged for just over $850.00 (labor was mine except for the aforementioned cleaning etc. of the evap. and evac. / charging. It has not lost 1 oz. of refrigerant in a year and a half, is quiet, will freeze you out of the car (as a couple of Orlando meet attendees found out), and, best of all, can be serviced at low cost almost anywhere. For any of you facing the R- 12 / convert / replace dilemma I suggest a visit to vintageair.com or a call to 800-TO-COLL-U to request a free catalog / price sheet. They offer unbiased suggestions / answers to the what to do question and are very helpful. Hey, they even feature a 200 mph Studebaker in their ads. / catalog that was running one of their systems AT 200 MPH!! Tom Gorr RQB3449 ------ the hose connections to the evaporator should be right in front of the evaporator at the firewall. But the system needs to have the freon pulled out into a recycler first. Then open the hose at the firewall and at the compressor itself. Have the hose made up locally at any hose or AC shop. You should NOT have to get under dash at all. The evaporator should have fittings coming thru the firewall to which the hoses attach. Once the compressor and hose are replaced it's just pump down with a vacuum pump and recharge. Dave '78 RQB 2670 -------- receiver driers can be gotten at local AC supply shops by visual matchup. Usually around $40-50. Dave '78 RQB 2670 ----