Old car air conditioning options


My 1986 Honda Accord (LXI hatchback, 2l FI) is the first car I’ve ever owned with an air conditioning system in generally good repair. The air currently comes out sort of luke-cold, I guess you’d say, which is just fine out here in Montana, but I’m planning a trip down to the southwest and am wondering what options I have for recharging it.

I remember a long time ago looking into doing an R134 conversion, but finding it hard to determine what all had to be changed to do so. Also, considering as I still have some freon in there, I would probably need to take it to a professional?

And what’s the deal with Freeze-12? Can you just use it with an unmodified R12 system?


just curious. does the air temp vary, or get “stuck” if you move the temp selector?

the valve which closes off the hot water loop to the heater core when the AC is on may be sticking open all the time (thus the too warm AC)

although you may need some refrigeration work, the valve is such an easy fix (even a caveman could do it) it may eliminate an expensive repair.

the real check is when you shut off the car, and turn the ac to coldest, then start the car is it ever cold? if you change the temp a little bit and it gets warm and wont change back to cold, then the valve is sticking.


I have used Freeze 12 to “top off” older R-12 systems with very good success. You will need some fitting adapters so you can connect to the old R-12 ports…


I doubt if it would be worth it to convert it for one trip. If you would use it on a regular bases, I would recommend the conversion however. I use my A/C even in the winter to help defog windows.

The Freeze-12 has received mixed reviews. When my girlfriends car needed a charge I passed on that one and went with the conversion. That was some years ago and it is still just fine with no additional service.


Just have it fixed and recharged with R-12, as designed. In the past, I have been disappointed with R-134a performance in older cars. I wouldn’t bother with Freeze-12 (which is a blend including mostly R-134a anyway), or any other “alternatives.”


Recharge it with R-12 well in advance of your trip and check the pressure to make sure it doesn’t lose pressure quickly. All A/C systems leak, it is just a question of how much. Your system may have adequate seals and might only need to be recharged once. You might prefer to replace seals, if needed, before you leave home and this allows you to do that. Of course, it will also mean that you will recharge the system twice if you need to replace seals.


So how much is R-12 going for these days?


stopped making it in 1995,I have a full 30 lb bottle of virgin Ill sell him.


Last time I bought some (retail) from my shop, I think it was about $60/pound. It’s available cheaper on ebay, etc.


Often you do not have to change anything to convert to R134. I’ve done a lot of them and encountered very few problems with either the conversion or pressures. With an old SAAB I used to own I did nothing more than repair the leak the system had, add a can of Ester oil and several cans of 134, and voila; low 30s air on a 100 degree day.

Once in a blue moon one may run into a pressure problem with 134 depending on the system since 134 is molecularly smaller than R12. This makes for a denser mass and may lead to slightly higher than normal high side pressures. This is rare and hopefully the A/C expert who runs into this knows how to get around it. It’s not a big deal IMHO.

I can’t speak for R12; never used it because 134 has always gotten the job done for me and done it well. Works fine here in OK where it’s usually brutally hot in the summer.


There is, to me at least, a surprising amount of variation in how well conversions can be made. It depends on variations in how the refrigeration systems are designed to start with. Some have plenty strong compressors but the evaporators that are marginal. Others have a different weakest link. That is why some systems work will with a simple refrigerant change and others do not, needing a more robust condenser coil for example. A real AC expert with lots of experience with conversions can tell you what needs to be done as soon as you pull up to the shop. If you looked into a conversion some time ago, you should probably check again. The knowledge base may have improved since then.

Deciding between an conversion and a fix and refill might also depend on what needs fixed too. A good pro evaluation with dye and a sniffer will really help there. The trouble is that a real good shop is likely to cost more than going to Joe’s muffin, coffee and auto air shop and it can really eat into what you can afford to spend on a '86 Accord.

At least you won’t need as much AC in the Southwest as you would in the South or Southeast.


There does seem to be a lot of variation. Unfortunately there aren’t really AC specialty shops around here so I’ll probably have to do some asking around to find someone with the expertise.

I think I’m probably going to stick with the if it ain’t (completely) broke, don’t fix it. It’s sounding to me like an alternative refrigerant might only get me back to where I am now, minus substantial bucks. I’ll probably just see how it fares this season and maybe if it gets worse I’ll consider playing with some of the other options.


Just out of curiosity, what kind of vehicle did you do that on? Was it completely out, or did you put it in with the R12? How did you know how much to put in?


Can’t you use the 4-60 system? It always works for me . . . never needs a recharge either. On the hatchback I guess it would be a 2-60, but it will still work. Rocketman


“Just out of curiosity, what kind of vehicle did you do that on? Was it completely out, or did you put it in with the R12? How did you know how much to put in?”

I have used it in several different cars. They all had the typical slow seepage, one can a year, and I simply installed one can of Freeze 12 with the fittings and hose provided in their installation kit. When the compressor stops cycling on and off and cold air comes out the vents, you’re done. You can also do it “right” and install it with a set of gauges so you can observe the pressures…If your system is completely empty, you might as well find and repair the leak and convert the system to 134a. Adding refrigerant to a badly leaking system is a waste of time and money…