78 ac conversion
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how i did a 1978 ac conversion
After reading many post over the last year and doing much research I decided to convert my ac to 134a this summer when the compressor died. After much research into r4 compressor brands I discovered that all r4 compressors are made by 4seasons in China and rebranded here in the U.S. So I just shopped price and picked up a new compressor and accumulator from AutoZone for just under $200 with an online discount. R134a works better in the C3 with a parallel flow condenser so I ordered one online for $119. A blue Ford .67 orifice tube is also supposed to work better with r134a than the stock orifice tube so I got one of those for $5. I went ahead and replace the ac hoses and manifold that attatch to the compressor for $119 although I probably could have kept the originals (I did not want to go back and have to do it later). I also had to fabricate new/custom connections for the parallel flow condenser which I did with aluminum U bend'em lines purchased from Summit for about $15 each.
Getting everything disassembled was time consuming but not difficult (I ordered a new champion aluminum radiator once I had the hood off and access was easy$175) reassembly was straightforward although getting the darned accumulator back in was a bit of a challenge even through the trap door in the bottom. I bought a cheap set of ac manifold gauges $89 and borrowed a vacuum pump from autozone to pull a vacuum and charge the system but ran into issues. The manifold would not seat properly onto my retrofitted ac ports and I was unable to pull a vacuum
. So instead I went to my local shop and had them pull a vacuum and fill with r134a.
So far on the short ride home I had ice cold ac. I will have to put the hood back on the car this weekend and button everything up. Once I do I will get a thermometer to see exactly what the vent temps are at idle and while driving and will post the results.
Getting everything disassembled was time consuming but not difficult (I ordered a new champion aluminum radiator once I had the hood off and access was easy$175) reassembly was straightforward although getting the darned accumulator back in was a bit of a challenge even through the trap door in the bottom. I bought a cheap set of ac manifold gauges $89 and borrowed a vacuum pump from autozone to pull a vacuum and charge the system but ran into issues. The manifold would not seat properly onto my retrofitted ac ports and I was unable to pull a vacuum
. So instead I went to my local shop and had them pull a vacuum and fill with r134a. So far on the short ride home I had ice cold ac. I will have to put the hood back on the car this weekend and button everything up. Once I do I will get a thermometer to see exactly what the vent temps are at idle and while driving and will post the results.
Last edited by chrisviktorjakematt; Jul 28, 2017 at 03:31 PM. Reason: clarity
Racer
Joined: Jul 2007
Posts: 397
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From: Jasper, GA
After reading many post over the last year and doing much research I decided to convert my ac to 134a this summer when the compressor died. After much research into r4 compressor brands I discovered that all r4 compressors are made by 4seasons in China and rebranded here in the U.S. So I just shopped price and picked up a new compressor and accumulator from AutoZone for just under $200 with an online discount. R134a works better in the C3 with a parallel flow condenser so I ordered one online for $119. A blue Ford .67 orifice tube is also supposed to work better with r134a than the stock orifice tube so I got one of those for $5. I went ahead and replace the ac hoses and manifold that attatch to the compressor for $119 although I probably could have kept the originals (I did not want to go back and have to do it later). I also had to fabricate new/custom connections for the parallel flow condenser which I did with aluminum U bend'em lines purchased from Summit for about $15 each.
Getting everything disassembled was time consuming but not difficult (I ordered a new champion aluminum radiator once I had the hood off and access was easy$175) reassembly was straightforward although getting the darned accumulator back in was a bit of a challenge even through the trap door in the bottom. I bought a cheap set of ac manifold gauges $89 and borrowed a vacuum pump from autozone to pull a vacuum and charge the system but ran into issues. The manifold would not seat properly onto my retrofitted ac ports and I was unable to pull a vacuum. So instead I went to my local shop and had them pull a vacuum and fill with r134a.
So far on the short ride home I had ice cold ac. I will have to put the hood back on the car this weekend and button everything up. Once I do I will get a thermometer to see exactly what the vent temps are at idle and while driving and will post the results.
Getting everything disassembled was time consuming but not difficult (I ordered a new champion aluminum radiator once I had the hood off and access was easy$175) reassembly was straightforward although getting the darned accumulator back in was a bit of a challenge even through the trap door in the bottom. I bought a cheap set of ac manifold gauges $89 and borrowed a vacuum pump from autozone to pull a vacuum and charge the system but ran into issues. The manifold would not seat properly onto my retrofitted ac ports and I was unable to pull a vacuum
. So instead I went to my local shop and had them pull a vacuum and fill with r134a. So far on the short ride home I had ice cold ac. I will have to put the hood back on the car this weekend and button everything up. Once I do I will get a thermometer to see exactly what the vent temps are at idle and while driving and will post the results.
So what did the shop do to fix the issue with the manifold seating properly onto the retrofitted ac ports ? New or different o-rings ?
Also, what do you mean by retro-fitted, you used a r4 compressor and a normal replacement manifold, please explain.
Richard
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I meant the high side and low side ports/Schrader valves. I used 90 degree angled r134a conversion ports that I ordered from napa since r134a ports are not the same as r12. The air conditioning manifold gauge set I bought was cheap and in the reviews a few people stated that they would not fit on their Schrader valves either. Rather than spend a couple hundred bucks on a quality set of manifold gauges that I might use a couple time I took it to the shop. They had no problems hooking up and pulling a vacuum.
Le Mans Master
Joined: Apr 2011
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From: Hermosa
After reading many post over the last year and doing much research I decided to convert my ac to 134a this summer when the compressor died. After much research into r4 compressor brands I discovered that all r4 compressors are made by 4seasons in China and rebranded here in the U.S. So I just shopped price and picked up a new compressor and accumulator from AutoZone for just under $200 with an online discount. R134a works better in the C3 with a parallel flow condenser so I ordered one online for $119. A blue Ford .67 orifice tube is also supposed to work better with r134a than the stock orifice tube so I got one of those for $5. I went ahead and replace the ac hoses and manifold that attatch to the compressor for $119 although I probably could have kept the originals (I did not want to go back and have to do it later). I also had to fabricate new/custom connections for the parallel flow condenser which I did with aluminum U bend'em lines purchased from Summit for about $15 each.
Getting everything disassembled was time consuming but not difficult (I ordered a new champion aluminum radiator once I had the hood off and access was easy$175) reassembly was straightforward although getting the darned accumulator back in was a bit of a challenge even through the trap door in the bottom. I bought a cheap set of ac manifold gauges $89 and borrowed a vacuum pump from autozone to pull a vacuum and charge the system but ran into issues. The manifold would not seat properly onto my retrofitted ac ports and I was unable to pull a vacuum. So instead I went to my local shop and had them pull a vacuum and fill with r134a.
So far on the short ride home I had ice cold ac. I will have to put the hood back on the car this weekend and button everything up. Once I do I will get a thermometer to see exactly what the vent temps are at idle and while driving and will post the results.
Getting everything disassembled was time consuming but not difficult (I ordered a new champion aluminum radiator once I had the hood off and access was easy$175) reassembly was straightforward although getting the darned accumulator back in was a bit of a challenge even through the trap door in the bottom. I bought a cheap set of ac manifold gauges $89 and borrowed a vacuum pump from autozone to pull a vacuum and charge the system but ran into issues. The manifold would not seat properly onto my retrofitted ac ports and I was unable to pull a vacuum
. So instead I went to my local shop and had them pull a vacuum and fill with r134a. So far on the short ride home I had ice cold ac. I will have to put the hood back on the car this weekend and button everything up. Once I do I will get a thermometer to see exactly what the vent temps are at idle and while driving and will post the results.
I also have read that the ford blue is supposed to give superior performance. One day when I have to pull my system apart I plan on installing that orifice. Glad to hear that it all went well.
I would be interested in what vent temp you are achieving at what outside air temp.
On the gauge set you have if the hoses screw off of the quick disconnects you can take off your R12 to 134a converters on the system's ports and screw the hoses directly to the R-12 ports. On my low side port there is not enough room to get the quick disconnect on with a standard converter (no 90* angle) so I just screw the hose directly to the R-12 port.
Last edited by REELAV8R; Jul 28, 2017 at 05:06 PM.
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parallel flow condenser
I believe this is the one I got. I went to ebay and found climate parts the manufacturer and ordered it from them. It is selling for $46 now.
