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Car Air Con

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Damian

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Mar 14, 2005
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I am having my car air con re-gassed on Thursday as it has not been as good as I think it should be in the heat we have had.
I would have used the Groupon thing but ATS shut down here a few months ago, but the local guy only charges £48 so not a great loss, and he is only about 1/4 mile from me.
 
Nov 11, 2009
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Had mine done today. Surprised that as a 2014 car it had the later, and much more expensive R1234yf refrigerant. Anyway ATS only booked me the extra cost at Groupon price.

The records show it had lost all its lubricant and 30% of its refrigerant. Vacuum test good. Much improved performance on way back. Also had the four tyres swopped front-rear-front and balanced too.

4E882F4E-A6D0-43C1-A1C1-1C9462BBB992.jpeg
 
Jun 16, 2010
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I'm of the opinion, if it ain't broke - don't fix it !

Especially after getting a 'bargain' price regas at a local fast fit style garage. They blew out my condenser after selecting the wrong car and putting twice as much refrigerant in than it held.

They also accepted no responsibility
 
Nov 11, 2009
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I'm of the opinion, if it ain't broke - don't fix it !

Especially after getting a 'bargain' price regas at a local fast fit style garage. They blew out my condenser after selecting the wrong car and putting twice as much refrigerant in than it held.

They also accepted no responsibility
So running mine on with zero lubricant would have been a good idea! New compressors aren’t cheap.
 
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Jun 16, 2010
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So running mine on with zero lubricant would have been a good idea! New compressors aren’t cheap.
Out of interest, wonder how the machine establishes it had no lubricant?

It's suspended in the refrigerant, wasn't aware that the machine could measure it as they recovered it.
 
Nov 11, 2009
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Out of interest, wonder how the machine establishes it had no lubricant?

It's suspended in the refrigerant, wasn't aware that the machine could measure it as they recovered it.
Perhaps there’s a conductivity test which is calibrated against the percentage lubricant.
 
Sep 24, 2008
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There are two items on our car which get constantly used. Me cruise control which I use all the time, my wife never fails to alter whatever setting the aircon is on she alters it without fail
 
Jan 3, 2012
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There are two items on our car which get constantly used. Me cruise control which I use all the time, my wife never fails to alter whatever setting the aircon is on she alters it without fail
I would have to agree my wife likes to alter the air con on her side all the time ;)
 

Damian

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Mar 14, 2005
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Well, had the car aircon done today and what a surprise.
The machine retrieved 160grams of old fluid, all pressure and vacuum tests perfect, refill with correct amount of fluid which should have been 780grams.
No wonder it was not as good as it should have been. Instant difference and really COLD.
The whole operation took 45 minutes.
 

Parksy

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Nov 12, 2009
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After having my aircon checked, lubricated and re-gassed last week it's still working and the car is nice and cool.
When the previous service centre attempted to add gas some time ago I was told that the system was leaking, so I was driving around with my window open for almost a year, it's a wonder that I didn't go deaf with the motorway noise.
Last week I went to a specialist air con company expecting an expensive visit.
The technician assured me that there was no leak so the testing and the remedy only cost me 50 quid 😁
 
Nov 11, 2009
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Well, had the car aircon done today and what a surprise.
The machine retrieved 160grams of old fluid, all pressure and vacuum tests perfect, refill with correct amount of fluid which should have been 780grams.
No wonder it was not as good as it should have been. Instant difference and really COLD.
The whole operation took 45 minutes.
Minevwas the same a 30% loss of fluid plus zero lub. The difference is most noticeable.
 
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May 24, 2014
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With the aircon, unless that is a major leak, its decreases its effectiveness in very small increments, so for a long time you dont realise its not as efficient as it was. Mine seems to be working fine, but Ill bet if I had it regassed the difference would be surprising.
 
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Jun 16, 2020
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I think there are 3 of us above who have had the re-gas done very recently, and all have shown to be 30-40% down. In my case, I assume they looked for leaks. The car label said there was an ultra violet tracer in the original gas. The gas is bad for the ozone, but even if there are no ‘proper’ leaks. A little is presumably getting passed the bearing seals. This will be happening on millions of vehicles.

My guess is the bearings are lubricated for life, and the tiny amount of lubricant added to the gas is to maintain the seals.

John
 
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Nov 11, 2009
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I think there are 3 of us above who have had the re-gas done very recently, and all have shown to be 30-40% down. In my case, I assume they looked for leaks. The car label said there was an ultra violet tracer in the original gas. The gas is bad for the ozone, but even if there are no ‘proper’ leaks. A little is presumably getting passed the bearing seals. This will be happening on millions of vehicles.

My guess is the bearings are lubricated for life, and the tiny amount of lubricant added to the gas is to maintain the seals.

John
Your print out showed they vacuum tested the system so there should be no need to look for leaks if the test is satisfactory. Which your was.
 
Nov 11, 2009
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A minor factor here. Change the pollen filter annually.
Do ours on the Kia dependant on mileage as per Kia’s schedule. I changed it last year took about five minutes very easy access. 2000 mikes later no plans to change it yet.
 
Jun 16, 2020
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Your print out showed they vacuum tested the system so there should be no need to look for leaks if the test is satisfactory. Which your was.
Good point. Nevertheless, the long term loss still ends up in the atmosphere.

Point of interest. Seems odd to do a vacuum test when the working system is under pressure. Gas systems, caravan or domestic, are tested under pressure. No doubt they know what they are doing.

John
 
Nov 11, 2009
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Good point. Nevertheless, the long term loss still ends up in the atmosphere.

Point of interest. Seems odd to do a vacuum test when the working system is under pressure. Gas systems, caravan or domestic, are tested under pressure. No doubt they know what they are doing.

John
I never linked your fluid loss to a leak. It’s a natural feature of the system. If there’s refrigerant still in, it vacuums it out into the collection system fir environmental safe disposal. It also allows the integrity of the system to be checked as air will be pulled in and the vacuum will not be developed properly. Pressuring the system would force refrigerant out into the environment.

At the end though as you say any losses from the system over time will enter the atmosphere. That’s why the new range of refrigerant has been introduced for more modern cars. My Subaru used R1234 which is more environmentally friendly than R123. And twice the price too.
 
Jun 16, 2020
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I never linked your fluid loss to a leak. It’s a natural feature of the system. If there’s refrigerant still in, it vacuums it out into the collection system fir environmental safe disposal. It also allows the integrity of the system to be checked as air will be pulled in and the vacuum will not be developed properly. Pressuring the system would force refrigerant out into the environment.

At the end though as you say any losses from the system over time will enter the atmosphere. That’s why the new range of refrigerant has been introduced for more modern cars. My Subaru used R1234 which is more environmentally friendly than R123. And twice the price too.
I did not think I had a leak as such either. But as with your caravan or house. The gas system will be pressure tested. Which is logical as the system is designed to work under pressure.

Yes the A/C gas is sucked out under pressure. And yes a vacuum test is feasible, except that flexible seals are normally designed to work either under pressure or vacuum. So testing a pressure seal with a vacuum is what I was questioning.

I agree that pressurising the system might force gas into the atmosphere, except the system would have been previously been purged.

I am not sure what you mean by ‘it’s a natural feature of the system’. I think it’s more likely that it’s an accepted loss. Mittigated to some extent by safer gas options. Like that used in your system.

John
 
Nov 11, 2009
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I did not think I had a leak as such either. But as with your caravan or house. The gas system will be pressure tested. Which is logical as the system is designed to work under pressure.

Yes the A/C gas is sucked out under pressure. And yes a vacuum test is feasible, except that flexible seals are normally designed to work either under pressure or vacuum. So testing a pressure seal with a vacuum is what I was questioning.

I agree that pressurising the system might force gas into the atmosphere, except the system would have been previously been purged.

I am not sure what you mean by ‘it’s a natural feature of the system’. I think it’s more likely that it’s an accepted loss. Mittigated to some extent by safer gas options. Like that used in your system.

John
The link gives information on how the procedure is conducted. And part of the procedure whilst under vacuum is checking for leaks. It’s not only seals that may leak other possible sources could be corrosion leaks, pipe joint leaks, O ring failure or stone induced penetration.
https://carfromjapan.com/article/car-maintenance/how-to-vacuum-ac-system/amp/

PS edit. A vacuum sensed leak is only the starting point to actually finding the leak. Some then use dye, others favour system pressurising with dry inert gas such as nitrogen or carbon dioxide.
 
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Damian

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Mar 14, 2005
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Having watched my car being done, it was all done by a machine. The mechanic connected two hoses to the two ports and fed the car details into the machine, the amount of oil that should have bene in there is on a label attached to the car scuttle near the ports.

The machine then went through all its checks, firstly creating a vacuum to draw out all old oil, then a pressure test before adding the new oil and gas.

Both vacuum and pressure tests have to hold their respective values for a specific time for the rest of the procedure to carry on.

The old oil was collected in a sealed container and was a disgusting colour compared to the new straw coloured oil going in .

The new oil contains a dye so that should there be a leak it is easy to locate.

The system runs at 5Bar pressure.
 
Jun 16, 2020
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The link gives information on how the procedure is conducted. And part of the procedure whilst under vacuum is checking for leaks. It’s not only seals that may leak other possible sources could be corrosion leaks, pipe joint leaks, O ring failure or stone induced penetration.
https://carfromjapan.com/article/car-maintenance/how-to-vacuum-ac-system/amp/

PS edit. A vacuum sensed leak is only the starting point to actually finding the leak. Some then use dye, others favour system pressurising with dry inert gas such as nitrogen or carbon dioxide.
A bit more research and I find that pressure testing is recommended by some. But using nitrogen. As in this extract.

In the book, I describe using nitrogen to pressure-test an empty air conditioning system in order to find leaks. I’ve long been surprised that this is not a widely used technique. Most of what you read online says either: A) You find leaks with a vacuum pump during the evacuation phase; B) If you previously filled the system with oil with dye in it, and it worked for a while but now is leaking, you find leaks by using an ultra-violet light to look for the dye; or C) You find leaks by using a chemical sniffer on a system that still has refrigerant in it.

From here.

It might be that places like ATS test with a vacuum simply because they have to vacuum it out anyway. Or, more likely in my opinion, that testing under pressure with air may introduce moisture and/or dust which is counter productive. And using nitrogen increases the complexity and cost.

Its all academic anyway. I was just being inquisitive.

Seems Damian’s tested with pressure.


John
 

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