Possibly overfilled AC system
#1
05-26-2020, 08:10 PM
Possibly overfilled AC system
I recharged my AC for the first time today. Mid day the gauges were reading 15-Low and 135-High while it was 95F outside. Later in the day I refilled to 40-Low and 200-High while it was 76F outside. I based the pressure on this chart https://i.stack.imgur.com/SBEAL.jpg which I now realize isn't universal.
According to this post https://www.mazdaforum.com/forum/maz...-charge-23781/ I may have overfilled the system.
The refill did something though because before there was absolutely no cooling at all. But now the AC is at least cool, but not cold, about -10 from ambient temperature.
Should I remove some of the refrigerant? or is this pressure okay? I haven't been able to find a number that is specific to my car.
2006 Mazda 3
edit: today I emptied some refrigerant into a tank a neighbor had. The new pressures are now 24-low and 175-high at 84F
According to this post https://www.mazdaforum.com/forum/maz...-charge-23781/ I may have overfilled the system.
The refill did something though because before there was absolutely no cooling at all. But now the AC is at least cool, but not cold, about -10 from ambient temperature.
Should I remove some of the refrigerant? or is this pressure okay? I haven't been able to find a number that is specific to my car.
2006 Mazda 3
edit: today I emptied some refrigerant into a tank a neighbor had. The new pressures are now 24-low and 175-high at 84F
Last edited by rujoesmith; 05-27-2020 at 01:39 PM.
#2
05-26-2020, 11:34 PM
You have more problems then the incorrect refrigerant.
I would strongly recommend to look into taking it to a shop that advertises ASE Certified Technicians in AC/Heating service and get your AC system checked. SOON!. Incorrect pressure in a AC system can damage the compressor/ clutch and the parts and adding the labor is not inexpensive to have done.
For DIY I have recommend to use
or other that are similar products . These are pretty "FOOL PROF " for a DIY.
AC refrigerant really does not need to be recharged if the AC system is not leaking the refrigerant or a part fails and needs to have the refrigerant removed for installation of the failed part. That's what the AC recovery systems do in service shops.
Most shops basic AC service should be about 135-155 plus refrigerant.
I would strongly recommend to look into taking it to a shop that advertises ASE Certified Technicians in AC/Heating service and get your AC system checked. SOON!. Incorrect pressure in a AC system can damage the compressor/ clutch and the parts and adding the labor is not inexpensive to have done.
For DIY I have recommend to use
A/C Pro Ultra Synthetic R-134a Refrigerant Recharge Kit - 20 OZ
or other that are similar products . These are pretty "FOOL PROF " for a DIY.
AC refrigerant really does not need to be recharged if the AC system is not leaking the refrigerant or a part fails and needs to have the refrigerant removed for installation of the failed part. That's what the AC recovery systems do in service shops.
Most shops basic AC service should be about 135-155 plus refrigerant.
#3
06-03-2020, 06:13 AM
R134A has been used as an automotive air conditioning refrigerant for more than 25 years and in industry for even longer. Refrigeration engineers were initially caught out during its introduction to the refrigeration environament. It was found that minor pressure anomolies seemed to be causing the refrigerant to become ineffective. Pressures seemed to be about right but the refrigerant just didnt seem to work. People involved in the manufacture of catering refrigeration equipment found out the reason for this:
R134A is a compound of various constituents. One of the constituents has a very small molecular size and is very good at finding leaks in the system. What they found was that this minor constituent was migrating out of the system through porous copper piping which had a degree of porosity which wouldnt allow the larger moleculaer sizes through but would allow the smaller molecules through and so... this explained the almost but not quite perfect pressures and yet refrigerant systems which almost ceased to function. In every case the manufacturers discovered that totally removing the refrigerant and recharging with entirely new refrigerant reinsated the performance of the system but only temporarily until those smaller molecules migrated. The way they found this was to dismantle their refrigerators and immerse the whole refrigerant system in a water tank whereupon they found the leaks. The molecular size of the ultraviolet dies they have attempted to use was actually greater than the since of the pores in the copper and so there didnt appear to be any detectable leaks.
The conclusion to all this is that totally replacing the refrigerant in R134A systems is quite commonplace as a "fix" in the automotive industry since leaks are all but indetectable with the technology available to the automotive service industry.The worst porous systems will require attention on a 6 monthly basis which in many markets is deemed acceptable since the air conditioning is only used in anger for around 6 months. Local and global refrigerant regulations dictate that air conditioning repairs must be proven by detailed detection of leaks which , of course, cant reveal the true culprit since the pressure difference is very minimal and dies are only effective with leaks which allow particles of equal or greater size of the detection fluids to escape.
I once had an issue with a 134A system on a Volvo and I called in a friend of mine who had undergone a full 5 year apprenticeship in refrigeration engineering. I had recounted the liquid and vapour pressure gauge scenario to him and he started to smile knowingly. I already knew about the R134A anomoly, as did he. and he proceeded to remove all of the refrigerant, triple vacuum the system using dry nitrogen and recharge the system using the refrigerant still technique since this is far more accurate and reliable than using pressure gauges , particularly with R134A. My friend regularly uses this same technique on agricultural systems in modern tractors and harvesters in addition to Ferrari road cars which share similar packaging issues ( there is hardly enough space to work) with agricultural machinery. The reason he uses this technique is that he has far fewer call backs. Having done all this I asked "ok , so if I have for example, a porous core, what should I do?"
"Its cheaper in the long run to change the gas charge, sell the car and buy another car than to replace the core whether its an evaporator or condenser because core porosity is by design and material specification rather than an actual fault" came the reply" its not like you are just nipping up a flare nut which has worked loose . so get used to driving a hot car or sell it or fix it everytime the R134 migrates".
All this made a certain amount of sense. I used to go shooting with Mick and asked him if he could have another look at the car about 18 months later , He checked the off coil temperature of the evaporator and found it to be identical to the notes he had made at the time of regassing using his still method. From that we concluded that the original issue would have been most likely caused by a previous owner having the system professionally serviced by someone who routinely added refrigerant by gauge, unintentionally over-charging the system. All that should be required during a routine air conditioning service is cleansing of the cores and ductwork ,where possible, changing the pollen filter and checking the off coil temperature and cleansing of the evaporator condensate drain system.
R134A is a compound of various constituents. One of the constituents has a very small molecular size and is very good at finding leaks in the system. What they found was that this minor constituent was migrating out of the system through porous copper piping which had a degree of porosity which wouldnt allow the larger moleculaer sizes through but would allow the smaller molecules through and so... this explained the almost but not quite perfect pressures and yet refrigerant systems which almost ceased to function. In every case the manufacturers discovered that totally removing the refrigerant and recharging with entirely new refrigerant reinsated the performance of the system but only temporarily until those smaller molecules migrated. The way they found this was to dismantle their refrigerators and immerse the whole refrigerant system in a water tank whereupon they found the leaks. The molecular size of the ultraviolet dies they have attempted to use was actually greater than the since of the pores in the copper and so there didnt appear to be any detectable leaks.
The conclusion to all this is that totally replacing the refrigerant in R134A systems is quite commonplace as a "fix" in the automotive industry since leaks are all but indetectable with the technology available to the automotive service industry.The worst porous systems will require attention on a 6 monthly basis which in many markets is deemed acceptable since the air conditioning is only used in anger for around 6 months. Local and global refrigerant regulations dictate that air conditioning repairs must be proven by detailed detection of leaks which , of course, cant reveal the true culprit since the pressure difference is very minimal and dies are only effective with leaks which allow particles of equal or greater size of the detection fluids to escape.
I once had an issue with a 134A system on a Volvo and I called in a friend of mine who had undergone a full 5 year apprenticeship in refrigeration engineering. I had recounted the liquid and vapour pressure gauge scenario to him and he started to smile knowingly. I already knew about the R134A anomoly, as did he. and he proceeded to remove all of the refrigerant, triple vacuum the system using dry nitrogen and recharge the system using the refrigerant still technique since this is far more accurate and reliable than using pressure gauges , particularly with R134A. My friend regularly uses this same technique on agricultural systems in modern tractors and harvesters in addition to Ferrari road cars which share similar packaging issues ( there is hardly enough space to work) with agricultural machinery. The reason he uses this technique is that he has far fewer call backs. Having done all this I asked "ok , so if I have for example, a porous core, what should I do?"
"Its cheaper in the long run to change the gas charge, sell the car and buy another car than to replace the core whether its an evaporator or condenser because core porosity is by design and material specification rather than an actual fault" came the reply" its not like you are just nipping up a flare nut which has worked loose . so get used to driving a hot car or sell it or fix it everytime the R134 migrates".
All this made a certain amount of sense. I used to go shooting with Mick and asked him if he could have another look at the car about 18 months later , He checked the off coil temperature of the evaporator and found it to be identical to the notes he had made at the time of regassing using his still method. From that we concluded that the original issue would have been most likely caused by a previous owner having the system professionally serviced by someone who routinely added refrigerant by gauge, unintentionally over-charging the system. All that should be required during a routine air conditioning service is cleansing of the cores and ductwork ,where possible, changing the pollen filter and checking the off coil temperature and cleansing of the evaporator condensate drain system.
#4
06-03-2020, 08:45 AM
In the hands of people that know what they are doing and understand the complete AC System of the vehicle they are working on "GAUGES" to service an AC system on any vehicle work just fine. If you use a Factory certified technician or a current certified ASE Automotive Technician you are more likely to get the AC service correctly! . 
An over or uncharged AC system will not have good air temperatures out the vent which would alert the Technician to a problem and to re-check the pressures..
An over or uncharged AC system will not have good air temperatures out the vent which would alert the Technician to a problem and to re-check the pressures..
Last edited by Callisto; 06-03-2020 at 08:53 AM.
#5
06-03-2020, 10:44 AM
In the hands of people that know what they are doing and understand the complete AC System of the vehicle they are working on "GAUGES" to service an AC system on any vehicle work just fine. If you use a Factory certified technician or a current certified ASE Automotive Technician you are more likely to get the AC service correctly! .
An over or uncharged AC system will not have good air temperatures out the vent which would alert the Technician to a problem and to re-check the pressures..
An over or uncharged AC system will not have good air temperatures out the vent which would alert the Technician to a problem and to re-check the pressures..
#6
06-03-2020, 12:00 PM
I think that you've missed the whole point about R134A .The refrigeration professionals do in fact know their trade and I for one would sooner believe the account of a dedicated refrigeration professional rather than that of an auto mechanic/ engineer who just so happens to have some training and experience with auto air conditioning. The point is that gauges don't always work just fine.
, Gauges do work in the operation of those experienced and trained and as you put it you personally have no training or experience and your information is not only second hand but not even supported even in the HVAC industry! 
I keep a 30lb bottle of R134 on hand in my personal garage. LOL
Last edited by Callisto; 06-03-2020 at 12:08 PM.
#7
06-03-2020, 02:02 PM
you are clearly upset. I shall not continue to post .( retired manager of successful refrigeration company) I rather judge that you could probably tell successful
electrical engineers how things are too.
electrical engineers how things are too.
#8
06-03-2020, 02:17 PM
I managed a McDonald's once...but I am not a BURGER EXPERT!!!! ROLMAO
I don't try to post BS, pretend something I am not and never post things I do not not know well, have experience if not formal training and education and can support my comments if needed with EMPIRICAL DATA or will state otherwise as IMHO or IMO!!!!
My friend an Chemical Engineer at HELLA would love to hear from you to explain in better detail your about your earlier posting. LOL
HELLA, Inc.
201 Kelly Drive
Peachtree City
Ga 30269 USA
I would love to read a response what you "LEARN" should you contact them about leak detection methods for "AUTOMOTIVE INDUSTRY" provided by HELLA for years specifically for 134/134R AC Automotive Systems on this thread but I doubt you will post. LOL
OR you could even contact MAZDA, let them tell you some interesting facts and information on the subject of AC leak detection and the current material used in the manufacturing of AC parts for MAZDA and FORD vehicles! Hey if you don't like Mazda contact , BMW,MINI,Chrysler,Chevrolet etc., etc., etc.!
I think you and I have been down this road before... you are a DIY with 16 posts that IMHO lead me to think IMHO you are not even a very good one at that? And you like to argue and debate things that IMHO you really know little about yourself.
Last edited by Callisto; 06-04-2020 at 08:22 AM. Reason: corrected some really bad spelling lol
#9
06-04-2020, 11:08 PM
Everybody, please pick up your toys and put them back in you pram. Stop the friggin bickering.
If you want a proper automotive AC job go to someone who is qualified & experienced to do so.
If you want a proper automotive AC job go to someone who is qualified & experienced to do so.
#10
06-04-2020, 11:16 PM
If you want a proper automotive AC job go to someone who is qualified & experienced
Nice! hahahahaha!
pram
noun
BRITISH
- a four-wheeled carriage for a baby, pushed by a person on foot.