A/C Charging with Easy Cheap Safe Alternative Refrigerant
08-04-11, 10:09 PM
#1
A/C Charging with Easy Cheap Safe Alternative Refrigerant
I am knowledgeable about Auto A/C (as well as Home and Refrigeration etc). I am licensed, I have a 608 and a 609 certificate. I have EPA certified recovery equipment and am capable of doing everything 'by the book'. I keep R12 and have for years. I have helped lots of people with auto a/c for many years. BMW's, Porsches, Honda's, Toyotas, Mazdas yada yada yada. It is easy stuff for me. It ain't braggin' if you can do it. This is my reference for those of you on the forum who don't know me.
The FC was designed for use with R12. It works great with R12...but R12 is expensive and restricted. You must have a pass a test, pay a fee to get license. Leaving the politics out, most of the guys on this forum are just not interested in R12 for these reasons.
Why not convert to R134a? The serpentine condenser is just barely adequate for R12 use. The condenser capacity is woefully inadequate for use in an R134a conversion. With inadequate heat rejection capacity, a converted system will produce head pressures that run dangerously high. The hot high-pressure gas cannot reject enough heat and so does not completely condense in cases of high load. Thus the system will not cool well when you need it most, when it is HOT! Additionally, the excessive pressure can damage the compressor, make the engine more likely to stall at lights, burst the rubber lines, blow the fusible plug out of the dryer and just generally cause havoc.
If you install a parallel flow condenser, (not an easy task) this trouble is avoided. This option is expensive, tricky and not easily accomplished. I haven't done this on any of my FC's even though I am qualified and capable. Pain in the butt.
The FC was designed for use with R12. It works great with R12...but R12 is expensive and restricted. You must have a pass a test, pay a fee to get license. Leaving the politics out, most of the guys on this forum are just not interested in R12 for these reasons.
Why not convert to R134a? The serpentine condenser is just barely adequate for R12 use. The condenser capacity is woefully inadequate for use in an R134a conversion. With inadequate heat rejection capacity, a converted system will produce head pressures that run dangerously high. The hot high-pressure gas cannot reject enough heat and so does not completely condense in cases of high load. Thus the system will not cool well when you need it most, when it is HOT! Additionally, the excessive pressure can damage the compressor, make the engine more likely to stall at lights, burst the rubber lines, blow the fusible plug out of the dryer and just generally cause havoc.
If you install a parallel flow condenser, (not an easy task) this trouble is avoided. This option is expensive, tricky and not easily accomplished. I haven't done this on any of my FC's even though I am qualified and capable. Pain in the butt.
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Sujag (09-09-22)
08-04-11, 10:31 PM
#2
So, what are the Options Available???
Freeze12 works. Period. Con is that Freeze12 is not locally available. What do you do if you are out and need a can? Log onto Ebay and wait! 
HotShot, ES12, ES12a etc. are all HC blends. That means Hydrocarbon. Blends of Propane and Butane. They burn.
They explode. They are against the law!
EPA has a specific ruling against 'Sham Conversions' that are used as a justification to bypass the rules regarding HC refrigerant. Who cares? Ok, if that doesn't deter you, how bout this. They don't work worth a crap. Don't post up from Ontario, or Minnesota and tell me how great the HC blends are. They don't work well in high temperature high humidity areas. I have tried them in FC's and other cars that didn't work well with R134a.
Is this just my opinion? Yes it is, but I have invested lot's of time trying to make HC's work in an FC.
HC's Suck.
HotShot, ES12, ES12a etc. are all HC blends. That means Hydrocarbon. Blends of Propane and Butane. They burn.
They explode. They are against the law! EPA has a specific ruling against 'Sham Conversions' that are used as a justification to bypass the rules regarding HC refrigerant. Who cares? Ok, if that doesn't deter you, how bout this. They don't work worth a crap. Don't post up from Ontario, or Minnesota and tell me how great the HC blends are. They don't work well in high temperature high humidity areas. I have tried them in FC's and other cars that didn't work well with R134a.Is this just my opinion? Yes it is, but I have invested lot's of time trying to make HC's work in an FC.
HC's Suck.
08-04-11, 10:40 PM
#3
What We Need is a New Refrigerant!
If we could design a new refrigerant, what would we ask for? Let's aim high!
The temperature pressure curve should match that of R12.
It should be compatible with the current synthetic oils.
It should be chemically compatible with all current and past A/C system parts.
It would work in R12 cars or even in current R134a cars.
It should cool as well as or better than R12.
It should be tested and proven by car manufacturers, refrigerant manufacturers, government testing labs. How about all of this on 3 different continents???
It should not explode and burn your wife and babies.
It should be cheap.
I should be able to buy it at 7-Eleven. I said 7-fricken-Eleven. Or Home Depot. Or Office Depot. Or Fry's Electronics.
That is aiming high!
The temperature pressure curve should match that of R12.
It should be compatible with the current synthetic oils.
It should be chemically compatible with all current and past A/C system parts.
It would work in R12 cars or even in current R134a cars.
It should cool as well as or better than R12.
It should be tested and proven by car manufacturers, refrigerant manufacturers, government testing labs. How about all of this on 3 different continents???
It should not explode and burn your wife and babies.
It should be cheap.
I should be able to buy it at 7-Eleven. I said 7-fricken-Eleven. Or Home Depot. Or Office Depot. Or Fry's Electronics.
That is aiming high!
08-04-11, 11:33 PM
#4
Introducing Your New Refrigerant: Difloroethane AKA R152a
http://en.m.wikipedia.org/wiki/1,1-Difluoroethane
Tomorrow I will cover temp pressure charts, necessary tools, system capacity, charging proceedures, and
Everything You Always Wanted to Know About Recharging Your A/C*
*but were afraid to ask!
Tomorrow I will cover temp pressure charts, necessary tools, system capacity, charging proceedures, and
Everything You Always Wanted to Know About Recharging Your A/C*
*but were afraid to ask!
08-05-11, 12:11 PM
#6
I knew this would come up. There is actually an additive that is called 'Bitterment' designed to prevent huffing. I can find no details regarding this ingredient. I was concerned that the additive would have detrimental effects on the system performance, but I have seen none.
I have one car (toyota celica) running the stuff for 2 years, and an 88 FC running it for 1.5 years and my 90 vert running for 6 months with no trouble, degradation, leaks etc.
08-05-11, 06:49 PM
#7
Ok, Apply the Exclusion for Minnesota and Ontario to R134a as Well!
I am curious, why have the cars Ive converted, blow cold and do so for years without problems on 134?
Flush everyting out, replace r/d, New oil, suck,test and charge.
No fire and brimstone here, I mean if you have a different refrigerant thats great, but like I said nothing but trouble free conversions here.
Flush everyting out, replace r/d, New oil, suck,test and charge.
No fire and brimstone here, I mean if you have a different refrigerant thats great, but like I said nothing but trouble free conversions here.
...or you live in Minnesota 
.Hell, I can make 134a work in February in Dallas, which is about like your summer.
Words have meaning, especially in Physics. It is a Temperature/Pressure Curve. You guys up north don't have the temps we have in the south. It makes a difference in both load on the system and the pressures experienced. If it works for you, then fine, stop reading now before I totally offend you.
Ok, Greg didn't really say this: I made it up. But he would have before the thread is finished.
Minneapolis, MN
Temp: 83F
Feels like: 86F
Cloudy
Humidity: 60%
Wind: S at 8 mph
Updated: 8/5/11 6:05 PM CDT
Now for Argyle, TX
Temp: 106F
Feels like: 106F
Sunny
Humidity: 20%
Wind: SSE at 13 mph
On your 10 day forecast there is one single day where your HIGH TEMP is going to be as high as our for a low temp on the 10 day forecast. Yesterday when I left my house at 4:45 AM the temperature was 89*. That afternoon it was 109* and was still 105* at 10pm.
Enough for the Peanut Gallery and back to the Science.
Trending Topics
08-05-11, 09:19 PM
#9
Temperature Pressure Chart R12/R134a/R152a
Observe that the pressures of 152a are quite similar to R12.
Both R152a and R12 are lower pressure than R134a.
We accomplish the pressure desired.
R152a is Difloroethane.
R134a is Tetrafluoroethane.
The two share many characteristics, including compatibility with synthetic lubricants, PAG and Ester oils, along with O-rings and hose compatibility.
I have purchased R152a at Lowes, Office Depot, Walmart and Fry's Electronics. I have seen it at a 7-fricken'-Eleven.
Both R152a and R12 are lower pressure than R134a.
We accomplish the pressure desired.
R152a is Difloroethane.
R134a is Tetrafluoroethane.
The two share many characteristics, including compatibility with synthetic lubricants, PAG and Ester oils, along with O-rings and hose compatibility.
I have purchased R152a at Lowes, Office Depot, Walmart and Fry's Electronics. I have seen it at a 7-fricken'-Eleven.
08-05-11, 09:24 PM
#10
AGreen is absolutely correct! All the 152a duster cans are the exact same diameter as the old R12 cans. I am using a 35 year-old can side tap. You can buy the one AGreen shows on ebay for a few bucks.
08-05-11, 09:44 PM
#11
Now Some Other News- Consider the Environmental Impact!
Did you know that R134a is being phased out globally? But didn't 134a replace R12 because R12=bad for the ozone and R134a=good for the ozone????
Since we have saved the Ozone, the wadded-pantie types have a new Boogieman: Global Warming!
European mandates say that by 2011 new car models must have refrigerant with a global warming potential of less than 150. R134a has a global warming potential af 1300. By 2017, all cars in Europe must comply. Forced retrofitting looms for Europe.
German car makers have chosen CO2-carbon dioxide.
Other makers are considering various other refrigerants, including R152a. R152a has a global warming potential of just 140. As we have seen, it is nearly a straight drop-in for R134a. Tests by GM Delphi show that R152a is up to 17% more efficient than R134a and uses 10% less fuel for cooling. Australian government and University testing shows similar results.
R152a has just been approved by the EPA as an alternative Refrigerant.
Everything sounds great right? So why are *you* guys just now hearing about it?
Since we have saved the Ozone, the wadded-pantie types have a new Boogieman: Global Warming!
European mandates say that by 2011 new car models must have refrigerant with a global warming potential of less than 150. R134a has a global warming potential af 1300. By 2017, all cars in Europe must comply. Forced retrofitting looms for Europe.
German car makers have chosen CO2-carbon dioxide.
Other makers are considering various other refrigerants, including R152a. R152a has a global warming potential of just 140. As we have seen, it is nearly a straight drop-in for R134a. Tests by GM Delphi show that R152a is up to 17% more efficient than R134a and uses 10% less fuel for cooling. Australian government and University testing shows similar results.
R152a has just been approved by the EPA as an alternative Refrigerant.
Everything sounds great right? So why are *you* guys just now hearing about it?
08-05-11, 10:18 PM
#12
Wadded Pantie Types-Remember?
R152a can be burned.
It will not support ignition.
According the the EPA and the CPSC gases are either Non Flammable, Flammable or Extremely Flammable. R152a duster is approved as safe to spray in your office, kitchen living room and yes, in your car to clean off dust. You can spray it all you like. It won't support flame. It is safe in all these environments.
It will not sustain a fire, but it *can* be burned. It does not pass the 'flame-extension test' in which a jet of the aerosol is sprayed over a candle flame. If the flame extends, the gas does not pass and is labelled 'Flammable'.
If the flame travels back down the stream toward the nozzle, or if the flame can be supported when the candle is removed, it is labelled 'Extremely-Flammable'.
In the struggle to replace R134a, there are two contenders other than C02=
R152a and HFO-1234yf. The HFO=1234yf was rated EXACTLY the same as R152a until recently. The battle has shifted to enact new flammability standards to exclude one or the other of these refrigerants with the research and money power of Honeywell/Dupont behind the HFO=1234yf.
HFO=1234yf extends the flame 10 cm. and R152a extends the flame 25 cm. Perhaps an oversimplification of a complicated conflict.
So will R152a kill your wife and babies? You decide. I am using it in my wife's car. I am using it in my FC and my son's FC. I would never use a HC-Hydrocarbon refrigerant in any car.
Tomorrow, we cover charging procedure and rates.
It will not support ignition.
According the the EPA and the CPSC gases are either Non Flammable, Flammable or Extremely Flammable. R152a duster is approved as safe to spray in your office, kitchen living room and yes, in your car to clean off dust. You can spray it all you like. It won't support flame. It is safe in all these environments.
It will not sustain a fire, but it *can* be burned. It does not pass the 'flame-extension test' in which a jet of the aerosol is sprayed over a candle flame. If the flame extends, the gas does not pass and is labelled 'Flammable'.
If the flame travels back down the stream toward the nozzle, or if the flame can be supported when the candle is removed, it is labelled 'Extremely-Flammable'.
In the struggle to replace R134a, there are two contenders other than C02=
R152a and HFO-1234yf. The HFO=1234yf was rated EXACTLY the same as R152a until recently. The battle has shifted to enact new flammability standards to exclude one or the other of these refrigerants with the research and money power of Honeywell/Dupont behind the HFO=1234yf.
HFO=1234yf extends the flame 10 cm. and R152a extends the flame 25 cm. Perhaps an oversimplification of a complicated conflict.
So will R152a kill your wife and babies? You decide. I am using it in my wife's car. I am using it in my FC and my son's FC. I would never use a HC-Hydrocarbon refrigerant in any car.
Tomorrow, we cover charging procedure and rates.
08-09-11, 07:25 AM
#13
Life got busy, but tomorrow is coming!
You gotta make your own decision, but make it with as many facts as you can. I'm not poo-pooing this statement, however 134a decomposes into exactly the same materials. R12 does as well. And did you know that for most oF the history of R12 use, leak detecters were propane torches with a sniffing tube? When a leak was detected, the flame changed colors! We made hydrofluoric acid on every job...
Maybe before people run off and install this R152 it might be worth looking at more than flammability - like when it does burn what happens?
http://forums.anandtech.com/showthread.php?t=324811
Flash fire is not the only concern with R-152a. If ignited, R-152a decomposes into hydrogen fluoride which can be deadly toxic to the human body...
Upon contact with moisture, including tissue, hydrogen fluoride immediately converts to hydrofluoric acid, which is highly corrosive and toxic, and requires immediate medical attention.
http://forums.anandtech.com/showthread.php?t=324811
Flash fire is not the only concern with R-152a. If ignited, R-152a decomposes into hydrogen fluoride which can be deadly toxic to the human body...
Upon contact with moisture, including tissue, hydrogen fluoride immediately converts to hydrofluoric acid, which is highly corrosive and toxic, and requires immediate medical attention.
08-09-11, 01:55 PM
#14
R134a has a flash-point temperature. So does propane (duracool) and R152a. Flash point temperature has *absolutely nothing* to do with how flammable a gas or liquid is.
R134a is Non Flammable
All other pressurized containers
Contents under pressure. Do not use or store near heat or open flame. Do not puncture or incinerate container. Exposure to temperatures above 130°F may cause bursting
Flash point above 20°F and not over 80°F or if the flame extension is greater than 18 inches long
Flammable. Contents under pressure. Keep away from heat, sparks, and open flame. Do not puncture or incinerate container. Exposure to temperatures above 130°F may cause bursting.
Flammable. Contents under pressure. Keep away from heat, sparks, and open flame. Do not puncture or incinerate container. Exposure to temperatures above 130°F may cause bursting.
Flash point at or below 20°F or if there is a flashback at any valve opening or if the flame extension is greater than 18 inches long with flashback
Extremely flammable. Contents under pressure. Keep away from fire, sparks, and heated surfaces. Do not puncture or incinerate container. Exposure to temperatures above 130°F may cause burst
Extremely flammable. Contents under pressure. Keep away from fire, sparks, and heated surfaces. Do not puncture or incinerate container. Exposure to temperatures above 130°F may cause burst
08-14-11, 04:34 PM
#15
Tomorrow is here
Here is a list of what you need:
1- 3/16x14" adapter for the highside. Ebay or Ackits.com
1- vacuum pump. RENT at Autozone Free for 90 days...
1-side can tap Ackits.com or ebay
1-manifold guage set. Mine has 134a connectors and it has 1/4" hose ends, so I can remove the 134a connectors and use the hoses directly on the 1/4" connectors on the FC
1-` multipak of R152a Refrigerant. Did I mention it was cheap???
1- 3/16x14" adapter for the highside. Ebay or Ackits.com
1- vacuum pump. RENT at Autozone Free for 90 days...
1-side can tap Ackits.com or ebay
1-manifold guage set. Mine has 134a connectors and it has 1/4" hose ends, so I can remove the 134a connectors and use the hoses directly on the 1/4" connectors on the FC
1-` multipak of R152a Refrigerant. Did I mention it was cheap???
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kenneth_ugalde (11-07-21)
08-14-11, 04:43 PM
#16
First
If your A/C has never worked for you, replace the reciever drier. You will hate life if you don't. Take your old part with you to the parts store and make sure it is right. If your bracket is welded on to the body of the drier, you must have a replacement that is welded if you have the clamp on type, it must be clamp on.
Also, the drier should come with two new orings. Use them.
http://www.autozone.com/autozone/cat...&parentId=63-0
http://www.autozone.com/autozone/par...ier&store=1516
The R12 OEM drier is not made to tolerate synthetic oils which you will need to use with R152a.
LIFE WILL SUCK if you ignore this warning.
Also, the drier should come with two new orings. Use them.
http://www.autozone.com/autozone/cat...&parentId=63-0
http://www.autozone.com/autozone/par...ier&store=1516
The R12 OEM drier is not made to tolerate synthetic oils which you will need to use with R152a.
LIFE WILL SUCK if you ignore this warning.
08-14-11, 04:48 PM
#17
Add oil Ester Only!
No PAG None never on any system that has had R12 and mineral oil in it.
http://www.oreillyauto.com/site/c/de...word=ester+oil
Add about 3 oz of oil to the drier before you put the drier on the car. Lube the orings with ester before you assemble.
IF you have removed the compressor, turn it upside down to dump all the mineral oil out. Rotate the shaft both directions to get every possible drop of mineral oil out of the compressor.
Add a couple of oz of ester oil to the compressor on the bench. Rotate the shaft 15-20 times, then dump the oil with the compressor upside down. This is to flush out as much mineral oil as possible. Now add 3 oz of ester to the compressor and remount the compressor in engine bay. This step will assure the longest life of your system. I did this in 2005 on my vert. I have had ZERO trouble with my A/C since then.
Don't attempt to replace any orings unless you have the specific joint apart for another reason. The old orings will not leak if the joints haven't been taken apart! The hoses do not need replaced (unless they have leak). Dont make this process any more difficult than you must.
http://www.oreillyauto.com/site/c/de...word=ester+oil
Add about 3 oz of oil to the drier before you put the drier on the car. Lube the orings with ester before you assemble.
IF you have removed the compressor, turn it upside down to dump all the mineral oil out. Rotate the shaft both directions to get every possible drop of mineral oil out of the compressor.
Add a couple of oz of ester oil to the compressor on the bench. Rotate the shaft 15-20 times, then dump the oil with the compressor upside down. This is to flush out as much mineral oil as possible. Now add 3 oz of ester to the compressor and remount the compressor in engine bay. This step will assure the longest life of your system. I did this in 2005 on my vert. I have had ZERO trouble with my A/C since then.
Don't attempt to replace any orings unless you have the specific joint apart for another reason. The old orings will not leak if the joints haven't been taken apart! The hoses do not need replaced (unless they have leak). Dont make this process any more difficult than you must.
08-14-11, 04:51 PM
#18
Pull a vacuum
Since you have just replaced the drier we assume the system is empty.
Attach the highside adapter on the driver side near above the exhaust manifold.
Attach the red hose to the highside adapter.
Attach the blue hose to the new drier.
Attach the yellow hose to the Vacuum pump.
Check that both needles on the manifold gauge point to exactly -0- psi with the valves open and the hoses open also. If they do not, unscrew the clear covers and use a small screwdriver to zero both gauges.
Turn on the pump and open BOTH valves on the manifold gauge.
Let the vacuum develop. It must reach 30" on the gauge.
When the vacuum reaches 30", let the pump run for another 10 min, then close both gauge handles, shut off the pump and wait. The vacuum should hold at the exact level for 15-30 min without moving. If it doesn't run again for another 20 min. Try again. If it holds, move on. If it doesn't, you are out of luck and need a repair that is beyond the scope of this thread.
Attach the highside adapter on the driver side near above the exhaust manifold.
Attach the red hose to the highside adapter.
Attach the blue hose to the new drier.
Attach the yellow hose to the Vacuum pump.
Check that both needles on the manifold gauge point to exactly -0- psi with the valves open and the hoses open also. If they do not, unscrew the clear covers and use a small screwdriver to zero both gauges.
Turn on the pump and open BOTH valves on the manifold gauge.
Let the vacuum develop. It must reach 30" on the gauge.
When the vacuum reaches 30", let the pump run for another 10 min, then close both gauge handles, shut off the pump and wait. The vacuum should hold at the exact level for 15-30 min without moving. If it doesn't run again for another 20 min. Try again. If it holds, move on. If it doesn't, you are out of luck and need a repair that is beyond the scope of this thread.
08-14-11, 05:06 PM
#19
Since your Vacuum held...
With the valves still shut, turn off the vacuum pump and remove the yellow hose.
Attach the side tap to the hose and puncture the can. Aim this away from your eyes, wear eye protection etc etc.
BLEED THE YELLOW HOSE!
At this point, the yellow hose is half filled with air and half with 152a. We cannot have that air in the system. It is non-condensable and will cause all kinds of problems. Air is the system from sloppy or ignorant charging is probably the #1 problem with DIY A/C work.
Very slightly unscrew the manifold end of the yellow hose. Some gas will start to bleed out. You WILL be able to tell when the R152a gets there-it will be cold. Tighten the hose.
You are now ready to charge!
Attach the side tap to the hose and puncture the can. Aim this away from your eyes, wear eye protection etc etc.
BLEED THE YELLOW HOSE!
At this point, the yellow hose is half filled with air and half with 152a. We cannot have that air in the system. It is non-condensable and will cause all kinds of problems. Air is the system from sloppy or ignorant charging is probably the #1 problem with DIY A/C work.
Very slightly unscrew the manifold end of the yellow hose. Some gas will start to bleed out. You WILL be able to tell when the R152a gets there-it will be cold. Tighten the hose.
You are now ready to charge!
08-14-11, 05:11 PM
#20
Open the Blue-low side valve.
Close the red highside valve after you vacuum. When you are charging you are never going to open the valve on the RED-High side!
With the can tap on the bottom of the can you will get liquid into the system. This is what we want initially. The combination of the vacuum and the liquid will allow most of the first can to enter the system.
Start the car, turn on the air conditioning system. We want re-circulation button on. We want low fan. We want the temperature all the way down.
Put a thermometer into the center vent. Temperatures should begin to drop.
The rest of the first can will be drawn into the system. High pressures will be in the 150 range, low pressues will likely be in the 20-30 range. The compressor may cycle on and off periodically.
This is a good sign.
With the can tap on the bottom of the can you will get liquid into the system. This is what we want initially. The combination of the vacuum and the liquid will allow most of the first can to enter the system.
Start the car, turn on the air conditioning system. We want re-circulation button on. We want low fan. We want the temperature all the way down.
Put a thermometer into the center vent. Temperatures should begin to drop.
The rest of the first can will be drawn into the system. High pressures will be in the 150 range, low pressues will likely be in the 20-30 range. The compressor may cycle on and off periodically.
This is a good sign.
08-14-11, 05:32 PM
#21
Full Charge
When the first can is completely sucked into the car, you will be able to tell. The can will have attained ambient temperature and will have no cold spots.
The compressor should be cycling. Off at about 22 psi and back on at aboutj 40-45psi. Try to catch the pressure at that low pressure, then close the blue valve.
Remove the first can from the side-tap. Tap another can. If you do this with no delay, there is no need to rebleed the hose.
Open the valve and allow the entire second can to enter the system. You may have to have a helper hold the engine speed in the 2000-2500 rpm range.
You should only add gas, not liquid with the second can. As you do this, the can will get very very cold and the gas flow will slow. Use a pitcher of hot water to add heat and keep the refrigerant flowing.
When the second can is in the system, you will be fully charged with R152a. A full charge is around 20-22 oz. This is because of molecular weights being different.
You should be able to get 40* air at the center vent at low fan speeds at idle. At 2500 rpm, you should be able to get 40-45*air at the center vent. All temps measure with air on recirulate.
The compressor should be cycling. Off at about 22 psi and back on at aboutj 40-45psi. Try to catch the pressure at that low pressure, then close the blue valve.
Remove the first can from the side-tap. Tap another can. If you do this with no delay, there is no need to rebleed the hose.
Open the valve and allow the entire second can to enter the system. You may have to have a helper hold the engine speed in the 2000-2500 rpm range.
You should only add gas, not liquid with the second can. As you do this, the can will get very very cold and the gas flow will slow. Use a pitcher of hot water to add heat and keep the refrigerant flowing.
When the second can is in the system, you will be fully charged with R152a. A full charge is around 20-22 oz. This is because of molecular weights being different.
You should be able to get 40* air at the center vent at low fan speeds at idle. At 2500 rpm, you should be able to get 40-45*air at the center vent. All temps measure with air on recirulate.
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turbo_dave (08-31-17)
08-14-11, 05:32 PM
#22
Unhook carefully.
Wait until the pressure is at it's lowest, then remove the low side hose. I use two hands. One hand keeps the hose pressed and sealed against the fitting while the other hand unscrews the threads. When it is completely unscrewed, remove the hose. Put on a service cap! This is very important. Most of these old valves leak a bit. You can fight it and try to find a new valve, or you can put on a cap and seal it up.
Turn off the car, let it cool down before you remove the high-side hose. Spray some cool water on the condenser. Your pressure should be down in the 75psi range before you attempt to remove the high side hose.
Keep the pressure with one hand, unscrew with the other. You are going to get some liquid refrigerant spray out. You can get localized frostbite if you are not careful...
Goggles, eye protection etc!
Put a cap on the high pressure adapter. If you only have one car, leave the adapter on the connector and put a 1/4 cap on the adapter. They are easy to find. 3/16 caps are hard to find in a store, but are a easy to find in the salvage yard. Most 84-93 cars in the salvage yard had a 3/16" adapter. Half of those will still be in place.
Turn off the car, let it cool down before you remove the high-side hose. Spray some cool water on the condenser. Your pressure should be down in the 75psi range before you attempt to remove the high side hose.
Keep the pressure with one hand, unscrew with the other. You are going to get some liquid refrigerant spray out. You can get localized frostbite if you are not careful...
Goggles, eye protection etc!
Put a cap on the high pressure adapter. If you only have one car, leave the adapter on the connector and put a 1/4 cap on the adapter. They are easy to find. 3/16 caps are hard to find in a store, but are a easy to find in the salvage yard. Most 84-93 cars in the salvage yard had a 3/16" adapter. Half of those will still be in place.
08-14-11, 05:35 PM
#23
Check for leaks
Check for leaks with a spray bottle of soapy water. 3-4oz of Dawn in 16 oz sprayer filled with water will give you an easy way. Spray all the connections that you had apart. If you have leaks, there will be voluminous bubble production. If you used the correct orings on the drier, you should be in fine shape.
08-20-11, 09:10 PM
#25
seems pretty easy to do. I'm tired of buying that stupid r134a crap. so expensive. i replaced the compressor, drier, and the expansion valve and a bunch of o-rings have been replaced as well. before i messed with the system, I had this hiss noise that would turn on with the a/c system. strangest thing. bad, but strange. now there is no hiss.
just to clarify, do all cleaning duster cans have the difluoroethane? i just bought a 3 pack today.
just to clarify, do all cleaning duster cans have the difluoroethane? i just bought a 3 pack today.
The hissing sound is usually the sound of refrigerant and flash gas (un-condensed gas) moving through the expansion valve. The flash gas does not contribute any to cooling capacity, but rather detracts from it. Can be caused by low charge, non-condensable gases in the system, by dirty condenser, low fan output or by using R134a which will only condense fully under optimal conditions.
