Converting to R134

beater89scbird

Registered User
Im bringin my bird out to texas for my sophmore year at A&M, and i need to convert my A/C to R 134, i heard its not to hard of a conversion, can anyone direct me in the right direction or tell me exactly what to do? I know i wont last long without A/C, especially being from CA.
 
Are you still in San Diego? If so, I have someone that can do the conversion and charge the system for a very reasonable price.

Paul
 
beater89scbird said:
The car is in San Diego, im in Texas doing summer school, but what is the price?
Yea, the old R12 systems can be recharged with R12 but it is real expensive and the cost to have it converted and charged is about less money. If you stay with R12 then it will be more expensive down the road. Once converted, recharging an R134a system is real low in cost and easy to do.

There are conversion kits available but I don't know if you can get them over the counter because the EPA might not let that happen because it has to be evacuated before hand. There are adaptors for your low and high access points. If I remember correctly, one gets a blue (low) connector and the other gets a red (high) one. If you can't evacuate the system yourself then bring it into a shop and have someone do it. A typical lube shop normally does this for under $60.00, could be more or less depending where you live. They might do the conversion kit too. The refrigerant kits are sold almost everywhere if you just need to recharge a converted system. It should come with the refrigerant and oil. You need both. I get mine at Walmart. You always recharge at the blue connector located near the passenger’s side front shock. Make sure the system has been running for about 5 minutes before you start. Once there’s enough initial pressure the compressor will begin to engage intermittently. You’ll want to make pressure checks throughout the recharge and keep recharging until it’s up to the correct working pressure. Again, let the system run during charging. Once fully charged, the compressor will stay engaged. Let it run 5 minutes and take another reading on the gage to insure it’s correct. Whatever you do, don't overcharge the system as it could damage your A/C system.

If you just want to get it converted and charged by a shop typically it's a little under $200.00. Not really that bad if you don't know what you're doing or don't have a reliable pressure gage. Good luck.
 
I've noticed several people stating that once the system is charged up that the compressor runs contunuously. I was under the impression and every car I have ever owned the compressor cycles on and off. I t may run for about 30 seconds then cycles off for 30 then back on....

Me is confused, because if the compressor is to stay on all the time, then I have never had a car run a/c right....

Frit
 
Canadian R12

rickbtbird said:
R12 but it is real expensive.
R12 isn't hard to get in Canada ;) ;) Since my lil brother lives in the U.P. of Michigan, I'll drive up to visit him & get my R12 recharged in Canada.

Maybe Mexico is the same.

Must be that ONLY R12 from america kills the OZONE layer!!!!! (if you believe that ozone layer cr@p).

68COUGAR
 
Ive allways heard that R134A runs higher pressures than R12, so it staying on all the time wouldnt make sense to me. :confused:
 
fturner said:
I've noticed several people stating that once the system is charged up that the compressor runs contunuously. I was under the impression and every car I have ever owned the compressor cycles on and off. I t may run for about 30 seconds then cycles off for 30 then back on....

Me is confused, because if the compressor is to stay on all the time, then I have never had a car run a/c right....

Frit
I can only tell you what I've experienced. I just put a recharge of R134a on mine this summer because the pressure was low and the compressor was cutting off and on every 15 seconds. When I tested it the gage said below 25psi. I got a can of r135a with oil and pumped it up to around 35-40psi. I tested it for over 10 minutes with the hood open and the compressor stayed on continuously with the full change. It is possible that it's shutting down at some point but I just haven't noticed it. Talk about cool air too. I have a little meat thermometer in my dash vent and when the AC is cranking it say between 42 and 45 degrees Fahrenheit.
 
68COUGAR said:
R12 isn't hard to get in Canada ;) ;) Since my lil brother lives in the U.P. of Michigan, I'll drive up to visit him & get my R12 recharged in Canada.

Maybe Mexico is the same.

Must be that ONLY R12 from america kills the OZONE layer!!!!! (if you believe that ozone layer cr@p).

68COUGAR

Well since he's from Texas and his car is in San Deigo I'm guessing he'd have to go south of the border to get an R12 charge. In New England the cost in gas would viod out any cost saving going to Canada. BTW, who needs A/C in Canada?
 
I just had my SC recharged with Freeze 12, and it works great. I didn't know it then, but seven years ago, after replacing most all the A/C components, it was charged with Freeze 12. It was real cheap too.
 
rickbtbird said:
Well since he's from Texas and his car is in San Deigo I'm guessing he'd have to go south of the border to get an R12 charge. In New England the cost in gas would viod out any cost saving going to Canada. BTW, who needs A/C in Canada?

I do, I've seen days hitting 105 with the humidex (what happened to the days where you could go outside all day and it never got really hot.... and yes it does in fact have something to do with the Ozone layer) , and because I'm so used to the cold air, 75 is getting too warm.....

Frit
 
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compressor should stay on

Your a/c system is controlled through a thermostat and a pressure switch.

Pressure = temperature so as the pressure drops the temperature drops.

as the temperature goes up and the pressure rises in the system the compressor is engaged. Once the pressure drops below the set point of the pressure system the low pressure switch shuts the system off.

In an undercharged situation the temp/press goes up the compressor comes on. Because you are under charged the system pulls the pressure down very quicklyand the pressure switch shuts the system off rather than the thermostat shutting down the system.

So you have a continuous call for cooling but you are cycling the system on the pressure switch. This is bad. It is hard on the system. Refigeration a/c systems like to run for extended periods of time. A/C systems are usually suction cooled so if they don't run for extended periods of time compressors get too hot, oil can breakdown causing sludge and acid build-up, and will shorten the life considerably.

The key rule for efficeincy in a/c system is as high a suction pressure as you can manage with as low a condenser pressure as you can manage. The proper charge is key to this.

if your a/c compressor is cycling every 30 seconds you are most likely low on refrigerant or in the odd case a thermostat or pressure switch is not working properly.

R-12 replacement refrigerants are an excellent choice rather than converting to R-134a. Conversion requires an oil change in the a/c system. R-134a systems must use a synthetic oil as the turn traditional refrigeration oils to a gummy residue. Unfortunately the synthetic oils absorb water aggressively, so much so that refrigeration mechanics rarely use a bottle of oil if it was opened before.

I would say don't be afraid of R-12 replacements and get your system charged properly.

sean
 
I just talked to several folks and none of them have never had cars where the compressor runs all the time including brand new cars. I took my car in and they tested the pressure and its right where its suppose to be, and the mechanic said if the compressor ran all the time and never shut off, the entire system would freeze up solid and you'd burn the compressor out......

My car also is ice cold with R134a in it.

So should I go tell my mechanic to go stuff it and fill the darn thing up till the compressor never stops running? On both my cars that is, the Corolla as well as the SC.

Frit
 
I have to agree with SDW, he is right. The clutch should not disengage under normal conditions. Cycling of the AC clutch 99% of the time indicates a low refrigerant level. I had my 93 concverted to 134a when the compressor blewup. That was an expensive change around $600-700. Since then, when the clutch starts cycling On / Off, I add around 8 oz of 134a and it is good to go for another year. :D

Now I still would like a definative answer about converting over a R12 to 134a without completely replacing the compressor etc. I also have a 90 that I need to get charged so I am contemplating whether it makes sense to have it converted now while the system needs to be completely pumped down and recharged, so that in the future, I can "service" it myself with 134a. :D
 
ruswin said:
Now I still would like a definative answer about converting over a R12 to 134a without completely replacing the compressor etc. I also have a 90 that I need to get charged so I am contemplating whether it makes sense to have it converted now while the system needs to be completely pumped down and recharged, so that in the future, I can "service" it myself with 134a. :D

Change the compresser? It's not necessary to do that, unless it's defective.
1. Have the system evacuated.
2. Have the conversion kit installed.
3. HAve it charged with R134a.
 
I know the compressor does not need to be changed. That was my question, what does the conversion kit consist of and what is involved to install it? Can someone provide a source for the conversion kit?
 
ruswin said:
I know the compressor does not need to be changed. That was my question, what does the conversion kit consist of and what is involved to install it? Can someone provide a source for the conversion kit?
Well it's a real joke.. couple of connectors that go on the high and low pressure inlets.

AMC045D.jpg

This might explain a few things
 
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