A/C convertion

[russiankid]

I am looking to see how much it would cost to convert my A/C to R134A. I have the Denso compressor so it will take R134A. I know I have to change the fittings, but what else? From what I know, the receiver and fittings have to be changed. An evac of R12 is also needed plus a recharge of R134A.

Also, where would I be able to purchase a receiver for R134A?

Thanks in Advance.

[nswst8]

Any parts store will have a R134a receiver.

If you are not real familar with charging use the pre mixed R134a.

[nswst8]

Basic Charging Procedures
REFRIGERANT CHARGING PROCEDURE IN AUTOMOTIVE A/C SYSTEMS

We recommend reading this procedure completely before charging. You may need information before charging you want to keep handy. Have this procedure with you while charging. Although it can be done by a single person, we recommend having a helper around.

This procedure outlines the steps to perform a complete charge. These steps are not to be used to refill or make partial charges. Toping off requires system parameters monitoring and knowledge, specially in R134a-based system. Excessive gas will harm your system and will keep it from cooling properly. MORE REFRIGERANT DOES NOT MEAN COLDER TEMPERATURES

CHARGING IN GAS OR LIQUID - Please read step 10

Do not use the sightglass (if so equipped) in R134a-based systems as if were R-12 based.

SPECIAL EQUIPMENT REQUIRED

1) Vacuum pump

2) Gauges (R12 or R134a)

3) Service port adapter (as required in most R12-based systems) R134a systems do not require adapters other than the couplers in your gauges in the majority of applications

4) Refrigerant gas (R12 or R134a)

5) Optional: 2-3 ounces of specified oil.

**************

1. Make sure what is the required amount of gas. From factory, all systems have a decal under the hood that give the data. If the decal is missing or you are not sure, please specify make, model, and the type of refrigerant used and whether your system is a factory or an after market unit here. It is very important to know if your system has oil. Oil starvation is the main reason of compressor failure. Oil can be added to the system in two ways: with oil injectors or through the low side port under vacuum. The procedure to add oil through vacuum is described here. Some refrigerant charge and other useful specifications are provided here.

2. Connect both blue and red gauge hoses to the system's service ports. The discharge port (red hose) is located somewhere between the compressor and expansion device, either before the condenser or after it. In R134a systems, the port is the thicker of both, while in R12 systems is the thinner one. In some aftermarket systems, the port is located in the back of the compressor. If your ports are located in the compressor, the low side is marked by an "S" and the high side by an "H". Port caps have an "L" for low or "H" for high.

3. Open both gauge valves. Connect the common hose (yellow one) to the vacuum pump. Make sure both gauge needles are zeroed down. Needle is adjusted by turning a fine screw inside the dial. You must remove the plastic lens to do this.

4. Turn the pump on. You'll notice that both gauge readings begin to drop. The blue gauge's needle will even dip into negative values. The desired low side reading should be less than -25, while the high side will remain at 0.

5. After approximately 5 minutes, close both gauge valves. Turn the pump off, and observe the needles. Any movement will indicate vacuum loss. The faster the movement, the greater the loss. If after two minutes you don't see any needle movement, open both valves, turn the pump on, and continue vacuum for not less than 30 minutes. Close both valves then turn the pump off.

6. Get ready to charge. Have the necessary refrigerant amount handy. Cans make charging easier and more precise unless you have a charging cylinder or a precision scale.

7. Disconnect the yellow hose from the vacuum pump and connect it to the can tap or charging cylinder valve. You can charge in two ways: liquid (can upside down) or gas. Liquid charging is a lot faster but not recommended unless you extreme care or have experience. Traditional (gas) charging is slower but safer.

8. Once you've decided, and with the can or container connected, unscrew the top yellow hose connection (at the gauges) allowing refrigerant to escape for a couple of seconds. This will purge the air out of the hoses so you make sure that all you dispense is refrigerant. You can do this venting in liquid form so you can see when a fine, steady stream of refrigerant escapes indicating that all the air is gone from the hose. Don't breathe refrigerant and don't charge in a flammable environment.

9. "Flood" the system with liquid refrigerant (can upside down) by opening the red valve (high side) until it won't take anymore. Close the red valve. Jump the low pressure cycling switch (if so equipped). If you don't know what this is or where it is, ask for help here.

10. Turn the engine on. Turn the A/C into MAX on its third or higher blower speed. You'll note that both gauge readings are now positive. The red gauge should read between 100 and 150, while the blue gauge between 5 and 15. If you are charging with cans, don't forget to purge air out the hose after hooking a new can as described in step 8 above. Now, charge will continue through the low (blue) side (see note below) . If you haven't jumpered any switch (you don't have to), you'll notice the compressor cycling frequently on and off. That is normal. The cycling will disappear as you dispense more refrigerant. The only disadvantage of frequent compressor cycling is that charge will take longer. Needles will move up and down with every cycle. This is normal. Do not jump any switch unless you are absolutely certain!.

WARNING: DANGER

NEVER OPEN THE RED VALVE WHILE CHARGING. The red valve is to be opened only during pre-charge, vacuum, or when a system is evacuated. Its function is keeping an eye on the high side only. It must be closed at all times. If you have any doubts, wait until you receive information. Severe injury or death may occur. Remember: ALWAYS wear safety goggles. NEVER charge your system in a closed environment.

GAS OR LIQUID CHARGING?

There are two ways to charge: gas (can or cylinder up), or liquid (can or cylinder upside down). A compressor is designed to compress gas. Direct liquid charge will harm the compressor if suction pressure is not controlled. Liquid charging is faster, yet is riskier. Liquid charging should be made by professionals or under supervision. Liquid charging can be done if the suction port is away from the compressor (some compressors have the suction valve in its body).

Liquid charging can be done never exceeding a 50 PSI suction pressure. If you can't control it, charge in gas form. In cooler weather, cans may freeze. You may immerse them in water and shake them while charging.

11. Once about 2/3 of the charge has been dispensed into the system, spray water in the condenser to optimize heat exchange and speed the process. When you get the condenser wet, vent temperature is likely to raise. This is normal. You'll also note pressure drop in both gauges.

12. Once the specified amount has been dispensed, close the blue valve. Let the system run for a minute. Turn the A/C off and then the engine. Wait another minute and disconnect the couplers from the service ports. Disconnect the low side first. If you jumpered a switch, reconnect it too.

Optimum cooling performance is attained after 10 minutes of operation. Our own acceptance criteria is at least 50°F in the center vent to the driver side at idle after 10 minutes or less. Remember: cooling increases while the vehicle is in motion.

VERY IMPORTANT

Due to the physical properties and chemical composition, R134a and R12 charging amounts are different. Never, if you are retrofitting, charge the same or specified amount of R12 with R134a. If in doubt, please e-mail us here. Do not use this procedure if you are using any other refrigerant. This is just for R12 or R134a. Although procedures and parameters may be similar, we do not use nor recommend alternative refrigerants.

HOW TO DETERMINE OPERATING PRESSURES

Every vehicle has its own operation parameters specification. Depending on whether or not the vehicle has a factory or an after market system, and whether it was retrofitted or is still original, among others. There is no established calculation to determine the exact operating pressures.

The low pressure (blue gauge) should be 35 or less at idle, regardless of the type of gas. Only if you're running a dual system, the low pressure may be between 45 and 50 at idle.

The high pressure, for starters, is directly related to ambient temperature: the higher the temperature, the higher the higher the pressure.

Bear in mind that dispensing a complete charge without lowering the pressures with water will result in higher readings. This is normal, and that is why you should spray water in the condenser at 2/3rds of the charge or once you have completed it. You'll note an immediate pressure drop when you spray water in the condenser.

To obtain a ballpark high side value, multiply ambient temperature by 2.2 if you have an R12 system. If you have a factory R134a system, use 2.3. To convert °C to °F, use this formula: °C X 1.8 + 32.

Remember: this is only a ballpark. If in doubt, we have factory charts to help you determine the correct pressures. Please have your vehicle's make, model, refrigerant type, and year and click here.

Factors like a an obstructed or very dirty radiator and condenser, weak or inoperative fan clutch, weak or inoperative radiator fan(s), either electric or mechanical, will make pressures go up and impair cooling, even in mild days.

[Blkblurr]

i just recharged my AC recently due to low cooling and this is what I measured. I converted mine to R134A several years ago but a little has leaked out since. I put one 12 Oz can of R134A in. I measured the vent temp before charging and got 72 deg f with outside air temp at 77deg F the car was in the garage at the time and I was not using the recirc air. Once charged, I measured 65 deg F while sitting. I got in the car to drive it around to get a better reading of actual ability and got 57 deg F with fresh air and 40 deg F with the recirc button on. This seems to be very good to me for a conversion and the original compressor (Denso)

[russiankid]

What did you actually change to run R134A? Or can I just evac the R12 and put in R134a?

Also, thanks for the write up on charging. I am going to a shop I know to get it charged with R12,but I still want to know what is involved in converting.

[Blkblurr]

I bought an R12 to R134A conversion kit from Advance auto that had the new fitting adapters on for low and high pressure, the oil stabilzer, and the R134a with labels to put under the hood to tell shops it has been converted to R1344A. I did not change thereceiver because I used my vacuum pump to pull the system down for about 2 hours to boil off the moisture in the system. I do however have the new unused reveiver that I would sell to anyone that has paypal. I didn't use it because it doesn't have the site glass in it.

[russiankid]

I bought an R12 to R134A conversion kit from Advance auto that had the new fitting adapters on for low and high pressure, the oil stabilzer, and the R134a with labels to put under the hood to tell shops it has been converted to R1344A. I did not change thereceiver because I used my vacuum pump to pull the system down for about 2 hours to boil off the moisture in the system. I do however have the new unused reveiver that I would sell to anyone that has paypal. I didn't use it because it doesn't have the site glass in it.

Do you remember how much the kit cost?

[nswst8]

The fittings are about $3.50 a piece. Any kit will run about 25-50 dollars depending where you get it from.

R134a is about $6 a can 2-12oz cans is all you will need, use the pre mixed cans so you won't have to worry about adding oil separately.

[russiankid]

So the ONLY things I have to change are the fittings?

[nswst8]

Let me tell you how I did my conversion. This is total "SHADETREE"

I ensured all connections were tight, install fittings, vacuum for 1 hour to boil off any moisture, charge.

I did not replace the drier but thats just me. If your not sure of the condition of your system you might want to replace the drier.

[nswst8]

So the ONLY things I have to change are the fittings?

If your not sure your system is sealed, I would replace the drier. My system still had R12 in it when I converted so I knew I had a good drier. Plus this was in 1997. Now I just replaced the original drier this year.

[Pico]

Let me tell you how I did my conversion. This is total "SHADETREE"

I ensured all connections were tight, install fittings, vacuum for 1 hour to boil off any moisture, charge.

I did not replace the drier but thats just me. If your not sure of the condition of your system you might want to replace the drier.

Thats how I did my Acura except I did change the drier.
Sam the kit that I got was similar to this one
http://img.photobucket.com/albums/v337/picopop/0121a.jpg

[russiankid]

Thanks guys. My A/C right now works fine but in hotter weather it isn't as efficient. I found a shop to charge it up for $120, which is to bad. The system hasn't been charged in 7 years, and the A/C was used daily.

[DBMaster]

I bought an R12 to R134A conversion kit from Advance auto that had the new fitting adapters on for low and high pressure, the oil stabilzer, and the R134a with labels to put under the hood to tell shops it has been converted to R1344A. I did not change thereceiver because I used my vacuum pump to pull the system down for about 2 hours to boil off the moisture in the system. I do however have the new unused reveiver that I would sell to anyone that has paypal. I didn't use it because it doesn't have the site glass in it.


You can't use the sight glass with anything but R12. If you get it to clear with R134a you put too much in and you risk an overpressure situation. The loss of readily available R12 in 1994 is pretty much the reason why the driers no longer have sight glasses in them.

Oh, also, receiver/driers are not refrigerant specific. They are just there to absorb any moisture in the system. Car A/C systems have a lot looser seal than home units or refrigerators. It's the nature of the beast.

[DBMaster]

The dryer has a dessicant bag in it. Think of it like the little dessicant packet that comes in new shoe boxes only bigger. You can't "boil" out the moisture it may have absorbed over the years by using a vacuum pump. It would have to be baked in an oven. It is important to replace it, but then, with R134a your system probably won't last long enough for moisture to cause a failure. The higher pressure will tax an already aged system and eventually cause a leak, or make an existing leak worse. I am going out on a limb here by saying I would use almost any other alternative refrigerant than R134a paying particular attention to those HC refrigerants that run at LOWER pressures than R12.

OK, now you can all rip me a new one. Everybody buys those R134a kits because they are cheap and readily available, but they are far from the best alternative.

[84Accord]

i just refilled mine with an r-12 compatible r134. haha. it works really well, didnt have to drain the system, cost about 5 bucks for the fittings and still works after 2 years

edit: i usd this exact same stuff bought on ebay for like 20 bucks for 4 cans or something like that
http://www.maxifrig.com/

[russiankid]

That is why I'll just get my system topped off and have it last another 6 or so years.

[DBMaster]

OK, here is what I want to hear. I don't want to hear, "My air is ice cold." I want to know what your vent output temperature is when it is over 90 degrees outside. (I mean sitting in traffic in gear at idle, not running in your garage.) I also want to know what your system's low side pressure is when you reach that temperature. The phrases "works really well" or "has worked for X years" are very subjective. If I know those two numbers I can tell you how close you are to R12 temps and how much additional pressure you have added to your system. The Maxi-Frig stuff mentioned is also a hydrocarbon refrigerant similar to the ones I have looked at. It most likely contains propane, butane, or both. That type of refrigerant is a much better solution for our cars - if you can't get R12. Cheap refrigerant is no substitute for a properly working system with no unusual leaks. 1/2 to one can of refrigerant a year is considered "normal" loss in a car A/C unit. If yours loses slower than that consider yourself fortunate.

It seems like this topic gets beat to death on this site. Not a week goes by that there are not two or more posts about refrigerant or questions about compressor compatibility with R134a. R134a sucks even in systems made for it. I can't figure out why that was the chosen R12 replacement since there are much better substances out there. The only thing I can think of is that since the others are combinations of really cheap ingredients somebody wanted to make sure that there was a big market for their proprietary refrigerant.

I also think I need to shut up and stay out of these threads because the more I read them the more pissed off I get about misinformation and people speaking as though they were experts. Even the experts don't agree with each other. Personally, I would shy away from R134a because I don't usually read posts about other refrigerants causing system failure. Does that mean your system will fail for sure? - NO. It just means that there are often risks associated with using functional components for which the system was not designed.

[nswst8]

Yeah, I'm with you on the misinformation that gets passed around.

You try to tell them the right way and they don't want to hear that. (Cost to much)

Its the cheapest way they can find and then whine, whine, whine.

As many times as I try to help out here on this subject alone I wish that a moderator would make it a sticky.

I get guys all the time bringing me their DIY a/c crap job cause they did not read the freakin instruction and what me to fix it at cost to them.
But after they take it around for estimates they always come back.

[russiankid]

I can't tell you the pressure or anything like that as I do not have the proper guages to measure the pressure. Sitting in traffic it blows 50F degrees.

[DBMaster]

Yeah, I'm with you on the misinformation that gets passed around.

You try to tell them the right way and they don't want to hear that. (Cost to much)

Its the cheapest way they can find and then whine, whine, whine.

As many times as I try to help out here on this subject alone I wish that a moderator would make it a sticky.

I get guys all the time bringing me their DIY a/c crap job cause they did not read the freakin instruction and what me to fix it at cost to them.
But after they take it around for estimates they always come back.

Awesome! I thought I was just turning cranky in my old age. Too expensive? R12 IS expensive compared to the 79 cents a can I used to pay when I was a college student. But, how much is a properly functioning air conditioner worth? Where I live it's like gold to me so I will continue to use expensive stuff as long as I can get it. If the system leaks so much that you need more than a can a year then you have bigger problems than deciding what kind of gas to use. If you are going through the trouble and expense of replacing major system components then why mess around to save $100. Wouldn't you want the new parts to last as long as possible?

I have noticed a good number of people driving around with the windows down recently. These are generally very new cars, too. I wonder if they just like the heat or are trying to prevent that 1-2 mile per gallon loss of fuel economy. When it's 100 outside (which it has been for several weeks now) your car gets up to almost oven temps when it's parked. If you want to be comfortable you gotta pay the man.

One of the other guys on here did some reading and charged his A/C with a mixture of propane (from a gas grill) and butane (from a Ronson can). He says he gets 37 degree air. That is even a little better than with R12. You current oil is also miscible in this gas so it won't just settle into the low spots. In the reading I have done, though, I found that a drawback of mixtures like that is differential leakage. If you have a small leak (which almost all car A/C systems do) you may leak more of one gas than another with the result being an inconsistent mixture as you top off the system. Pretty much all of the R12 alternatives are mixtures so who knows if that is truly the best way to go.

There ARE proper ways to switch to R134a but they involve quite a bit more than just adding a different gas and dumping in some new oil. Again, if you are spending $1,000 on new system components why would you look to save $100 on the refrigerant? Also, if you are fixing the system you will be fixing the larger leaks. $35 a year on refrigerant seems like a small price to pay to beat the heat.

[russiankid]

Agreed. I'll get it charged up and see how it goes. Right now my car failed NOx on emissions so I have to deal with that.

[DBMaster]

I have been reading the forum at aircondition.com for years. This post is very good, though it might have some political misinformation. The Geroge Goble he talks about is basically one of the online A/C gurus. I would strongly recommend that you read this and then make your own decisions.

http://yarchive.net/ac/r134a_conversions.html

[russiankid]

Just read the whole article. I am not going to do the conversion, I am going to stick to R12. Thanks for the link, much appreciated.

[steveko]

Check out this site.

http://bowesauto.com/

[russiankid]

Check out this site.

http://bowesauto.com/

I'd get Freeze 12 but a friend of mine used Freeze 12 in his R12 system(86' Accord) and the system stopped working completely.

[DBMaster]

Yeah, I've got one of those links, too.

http://hc12ausa.com/

I doubt Freeze 12 caused your friend's system failure. Freeze 12 is actually an EPA approved R12 replacement and is what the US military uses. The problem with all of this is that often people are putting some refrigerant (R12 or other) into a system that has other problems. Unless it is just a top off charge you are probably not going to have a "magic" fix by just adding refrigerant. I prefer to stick with R12 due to the differential leakage issue I mentioned. I have read articles stating that our non-barrier hoses become barrier hoses over time as the insides become oil soaked. Sounds plausible, but... If you charge with a mix of two or three different gases you could lose more of one gas than another due to molecular size. Once your mix ratio is off I would imagine that performance problems would follow. As long as your system is in good shape (This cannot be stressed enough) I would stay with R12 for reliability.

Would you say we have beat this topic to death now?

[russiankid]

Yeah, I've got one of those links, too.

http://hc12ausa.com/

I doubt Freeze 12 caused your friend's system failure. Freeze 12 is actually an EPA approved R12 replacement and is what the US military uses. The problem with all of this is that often people are putting some refrigerant (R12 or other) into a system that has other problems. Unless it is just a top off charge you are probably not going to have a "magic" fix by just adding refrigerant. I prefer to stick with R12 due to the differential leakage issue I mentioned. I have read articles stating that our non-barrier hoses become barrier hoses over time as the insides become oil soaked. Sounds plausible, but... If you charge with a mix of two or three different gases you could lose more of one gas than another due to molecular size. Once your mix ratio is off I would imagine that performance problems would follow. As long as your system is in good shape (This cannot be stressed enough) I would stay with R12 for reliability.

Would you say we have beat this topic to death now?
Indeed we have. I am sticking with R12, to much hassle and not enough gain to convert to R134a. :lock:

[lostforawhile]

has anyone thought of installing a 134 designed compressor in our systems? does anyone happen to know the direction the civic engines rotate from facing the pulley? i think one could be made to fit in the brackets for the existing compressor,then it would be hose adaptors, i believe vintage air could help with those.

[DBMaster]

has anyone thought of installing a 134 designed compressor in our systems? does anyone happen to know the direction the civic engines rotate from facing the pulley? i think one could be made to fit in the brackets for the existing compressor,then it would be hose adaptors, i believe vintage air could help with those.


It's not a compressor issue. The only issue I know of is that the Keihin compressor has a seal that is not compatible with the oil that you have to use with R134a. Any compressor will technically be fine with R134a, or any other refrigerant for that matter. The issue is that your system already has an incompatible oil in it, your condenser is too small, and your hoses are not barrier-type. If you replace the hoses and drier, replace the condenser with a parallel flow type, replace the pressure switch with one designed for R134a pressure, AND flush the entire system thoroughly then you can use R134a with acceptable results. What I mean by "acceptable results" is cold air coming out of the vents when you are stuck in Dallas traffic on a 105 degree summer day. That is where the el-cheapo "conversion" will disappoint you.

So, you can see why a proper conversion will cost you a good chunk of change. I guess if you don't care about the car that much, or you are planning to pawn it off on some unsuspecting person you could go the cheap route, but I find that to be unethical and just plain wrong. I see used car ads all the time that say things like, "A/C works, but just needs a charge." Bullshit! If all it needed was a charge they would have done it and they might be keeping the car. A/C system components have limited life spans and you gotta pay to play when the time comes. Cheap, half-ass fixes are exactly that. Why not just use plain tap water in your radiator because coolant has gone up in price? Why not pack some Crisco into your bearings instead of using grease? See where I am going with this?

[lostforawhile]

It's not a compressor issue. The only issue I know of is that the Keihin compressor has a seal that is not compatible with the oil that you have to use with R134a. Any compressor will technically be fine with R134a, or any other refrigerant for that matter. The issue is that your system already has an incompatible oil in it, your condenser is too small, and your hoses are not barrier-type. If you replace the hoses and drier, replace the condenser with a parallel flow type, replace the pressure switch with one designed for R134a pressure, AND flush the entire system thoroughly then you can use R134a with acceptable results. What I mean by "acceptable results" is cold air coming out of the vents when you are stuck in Dallas traffic on a 105 degree summer day. That is where the el-cheapo "conversion" will disappoint you.

So, you can see why a proper conversion will cost you a good chunk of change. I guess if you don't care about the car that much, or you are planning to pawn it off on some unsuspecting person you could go the cheap route, but I find that to be unethical and just plain wrong. I see used car ads all the time that say things like, "A/C works, but just needs a charge." Bullshit! If all it needed was a charge they would have done it and they might be keeping the car. A/C system components have limited life spans and you gotta pay to play when the time comes. Cheap, half-ass fixes are exactly that. Why not just use plain tap water in your radiator because coolant has gone up in price? Why not pack some Crisco into your bearings instead of using grease? See where I am going with this?well the system can be flushed,i'm suprised no one ever mentions this, the reciever dryer should be replaced every time you open the system anyway,and who says you can't use the dryer and hoses from the same car that came with 134 anyway? ac hoses can be made by a lot of shops. the main point is making sure they can be connected to the evaporator. i don't think the condensor is too small,people have had good luck getting these cars cool with the factory condensor. even if it's temporary, it shows that the condensor can be made to work. if you really wanted to do a conversion,get a complete vintage air system and figure out how to make the belts work, their systems are made to work in almost anything with wheels.

[nswst8]

Any system can be adapted, its the cost associated with the R&D.

I used ester in my R134s converted keihin compressor it was the suction side of the compressor that failed. But how can I complain it lasted 10 years.

Texas heat forced me to revert to R-12 once again.

[DBMaster]

well the system can be flushed,i'm suprised no one ever mentions this, the reciever dryer should be replaced every time you open the system anyway,and who says you can't use the dryer and hoses from the same car that came with 134 anyway? ac hoses can be made by a lot of shops. the main point is making sure they can be connected to the evaporator. i don't think the condensor is too small,people have had good luck getting these cars cool with the factory condensor. even if it's temporary, it shows that the condensor can be made to work. if you really wanted to do a conversion,get a complete vintage air system and figure out how to make the belts work, their systems are made to work in almost anything with wheels.

That would be awesome. Taking out the system from my 72 Catalina would literally freeze meat in this car. Only problem is that I don't think the A20A3 has enough power to turn that 6-cylinder compressor and still propel itself. Everything was oversized. It used a pound more Freon that my Accord and would blow 31 degrees in the heat.

[lostforawhile]

That would be awesome. Taking out the system from my 72 Catalina would literally freeze meat in this car. Only problem is that I don't think the A20A3 has enough power to turn that 6-cylinder compressor and still propel itself. Everything was oversized. It used a pound more Freon that my Accord and would blow 31 degrees in the heat.
the keihin compressor on my 81 civic had ten cylinders. would drag the car down,but it sure was cold. they were arranged inside like a radial engine,all the way around, and there are vintage systems that will work with gm compressors, just find one close enough to work,get it to turn,and they will provide the kit.

[2oodoor]

DBmaster , any examples of part numbers or vehicles to which to get the condensor you are talking about?

[Blkblurr]

OK, here is what I want to hear. I don't want to hear, "My air is ice cold." I want to know what your vent output temperature is when it is over 90 degrees outside. (I mean sitting in traffic in gear at idle, not running in your garage.) I also want to know what your system's low side pressure is when you reach that temperature. The phrases "works really well" or "has worked for X years" are very subjective. If I know those two numbers I can tell you how close you are to R12 temps and how much additional pressure you have added to your system. The Maxi-Frig stuff mentioned is also a hydrocarbon refrigerant similar to the ones I have looked at. It most likely contains propane, butane, or both. That type of refrigerant is a much better solution for our cars - if you can't get R12. Cheap refrigerant is no substitute for a properly working system with no unusual leaks. 1/2 to one can of refrigerant a year is considered "normal" loss in a car A/C unit. If yours loses slower than that consider yourself fortunate.

It seems like this topic gets beat to death on this site. Not a week goes by that there are not two or more posts about refrigerant or questions about compressor compatibility with R134a. R134a sucks even in systems made for it. I can't figure out why that was the chosen R12 replacement since there are much better substances out there. The only thing I can think of is that since the others are combinations of really cheap ingredients somebody wanted to make sure that there was a big market for their proprietary refrigerant.

I also think I need to shut up and stay out of these threads because the more I read them the more pissed off I get about misinformation and people speaking as though they were experts. Even the experts don't agree with each other. Personally, I would shy away from R134a because I don't usually read posts about other refrigerants causing system failure. Does that mean your system will fail for sure? - NO. It just means that there are often risks associated with using functional components for which the system was not designed.
Ac systems are rated on the ability to drop the temp from the ambient. So if it drops from 77deg to 57 in a garage it would drop from 90 to 70 in the sun as long as the dew point is the same. that's why the recirc button makes the inside of the car so much colder. The inside of the car becomes the ambient and the vent temp continues to drop as a result of cooling ambient. Once the inside reaches a point that the heat loss through the windows and leaks equals the cooling ability, the vent temp drop will level off.

[2oodoor]

Ac systems are rated on the ability to drop the temp from the ambient. So if it drops from 77deg to 57 in a garage it would drop from 90 to 70 in the sun as long as the dew point is the same. that's why the recirc button makes the inside of the car so much colder. The inside of the car becomes the ambient and the vent temp continues to drop as a result of cooling ambient. Once the inside reaches a point that the heat loss through the windows and leaks equals the cooling ability, the vent temp drop will level off.
most of your post is missing, but shows up in the quote !!!
I was going to add to your comment but, hell it shows up in the quote.. wth?
edit, that is weird now it is there!

[DBMaster]

DBmaster , any examples of part numbers or vehicles to which to get the condensor you are talking about?

There was a post a long time ago that linked to a site that sold just such a condenser.

I saw this looking pretty quickly.

http://www.gfactoronline.com/G%20Factor%20Factory%20Aire%20Page.htm

This company makes kits for converting to R134a which are obviously a little more complicated than dropping in new refrigerant and oil. I think the best thing to do if you do it yourself is to measure the current condenser dimensions and the mounting area dimensions. You would want to largest parallel flow condenser you could find to fit within that area. Several sites talk about replacing the condenser fan with a higher CFM model, or adding an additional fan to the front of the condenser. That would have added benefits for the engine compartment as well.

The whole issue is like a rash on the internet. There are so many opinions out there it leaves you still wanting to fend for yourself.