Air Con Reservoir.

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So you believe Mercedes when they say some gearboxes are sealed and need no maintenance......ever? :rolleyes:
I think he's confusing automotive AC with residential AC, in residential AC it is a sealed system, whereas in automotive it's not 100%. Refrigerant gas does not 'wear out'. Unlike automatic transmission fluid.
 

It has oil in it too as well as gas. The oil is good to replace for obvious reasons. The AC system gas quantity reduces about 10% of per year. Lack of gas will make the AC system will make it work harder especially when its at full yield.

When you spend time fixing AC systems for 20 years and have done the training courses and certification to operate and handle AC gas you tend to pick up a few things.
 
The other place that AC gas will escape from is the O-rings, the PAG oil helps to keep them from hardening. When my condenser got pinged by a stone there was an oily patch surrounding the pin hole were the oil had come out with the gas.
 
It has oil in it too as well as gas. The oil is good to replace for obvious reasons. The AC system gas quantity reduces about 10% of per year. Lack of gas will make the AC system will make it work harder especially when its at full yield.

When you spend time fixing AC systems for 20 years and have done the training courses and certification to operate and handle AC gas you tend to pick up a few things.
Agree with everything there apart from the part about replacing the oil. Do you replace the oil periodically in your residential aircon or even your fridge? Maybe after 10 years but even then it's a bit over the top imo. It's not like engine oil that comes into contact with combustion gases & becomes acidic or gets contaminated by carbon, breaks down with the extremes of heat encountered in an engine or like ATF that gets contaminated by the brake band particles in an automatic transmission.
If we are declaring qualification I'm a refrigeration / air conditioning engineer of 33 years btw.
 
Agree with everything there apart from the part about replacing the oil. Do you replace the oil periodically in your residential aircon or even your fridge? Maybe after 10 years but even then it's a bit over the top imo. It's not like engine oil that comes into contact with combustion gases & becomes acidic or gets contaminated by carbon, breaks down with the extremes of heat encountered in an engine or like ATF that gets contaminated by the brake band particles in an automatic transmission.
If we are declaring qualification I'm a refrigeration / air conditioning engineer of 33 years btw.
:thumb:
But your home, office or fridge is not subject to such temperature differences or constant on and off situations. AC oil in cars does get filthy. The waste oil container in my AC machine tells me that.
I'm not disagreeing with you at all, just an interesting comparison.:)
 
So you believe Mercedes when they say some gearboxes are sealed and need no maintenance......ever? :rolleyes:

That's about as sensible as arguing that you can scuba dive in a space suit. It's two completely different systems, and Mercedes Benz suggesting life time fluid at the time made about as much sense to anybody who was familiar with automatic transmissions as regular reg-gas for an a/c system makes sense to anybody who knows anything about a/c systems.

Anyone who's telling you that probably does not have the know how to diagnose and fix a system properly so they're suggesting you keep nursing it along as the get a returning business for not fixing a problem.

But you can believe anything you like. It's your ignorance and your money. Offering this nonsense as advice is going to get challenged.
 
That's about as sensible as arguing that you can scuba dive in a space suit. It's two completely different systems, and Mercedes Benz suggesting life time fluid at the time made about as much sense to anybody who was familiar with automatic transmissions as regular reg-gas for an a/c system makes sense to anybody who knows anything about a/c systems.

Anyone who's telling you that probably does not have the know how to diagnose and fix a system properly so they're suggesting you keep nursing it along as the get a returning business for not fixing a problem.

But you can believe anything you like. It's your ignorance and your money. Offering this nonsense as advice is going to get challenged.
I see that you are suggesting that I offer this advice to gain work. I assure you that my workshop does not operate in this manner. Can you prove my advice is nonsense?
 
Can you prove my advice is nonsense?

I'm not here to educate you. If you want to understand how air conditioning systems function, you can read up on them as can anyone reading this this thread. As I had already stated, it's a sealed system and if anyone wants to understand your theory as to how a sealed system requires a biennial refill. They can ask you and you can explain it to them.
 
I'm not here to educate you. If you want to understand how air conditioning systems function, you can read up on them as can anyone reading this this thread. As I had already stated, it's a sealed system and if anyone wants to understand your theory as to how a sealed system requires a biennial refill. They can ask you and you can explain it to them.
Never said a re-fill. If the gas has all gone then there is a leak. If the AC doesn't work then there is a reason for that. We don't just gas cars up and hope for the best. To keep it working well, doing a service every two years is ideal.
I think you are confusing AC service and gassing cars up if the AC doesn't work.
You didn't answer my question.
 
I'm not confused. Here's what you said right here:

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There's no need to double down. If you think that you know more than I do about this then this is fine. You will know more than I do and you're speaking nonsense. An A/C system does not need to be re-gassed every two years to keep it in good nick.

You indicated earlier that I might be suggesting that you have said this to gain work. That's also nonsense I was very clear in what I said. I'm not interested in hurting your business. We're not competitors and even if we were, I don't compete by trashing anyone's livelihood. You said something on a public forum that's not correct and I simply called you on it.
 
Al, vehicle AC is not a sealed system, a certain amount of leakage via the compressor drive shaft seal is deemed acceptable by the industry. Because of that a car AC will need re-gassing every 8 to 10 years on average. It depends on the quality of that seal & usage, it can be as frequent as every 2 or 3 years, as in the case of my vans that do 800 miles a week, it can be never, as in the case of my mate's 1996 Volvo that's on it's original gas charge & still blows icy cold.
 
Al, vehicle AC is not a sealed system, a certain amount of leakage via the compressor drive shaft seal is deemed acceptable by the industry. Because of that a car AC will need re-gassing every 8 to 10 years on average. It depends on the quality of that seal & usage, it can be as frequent as every 2 or 3 years, as in the case of my vans that do 800 miles a week, it can be never, as in the case of my mate's 1996 Volvo that's on it's original gas charge & still blows icy cold.

Phil, I think that what you mean to say is that it is a sealed system where a certain amount of leakage is acceptable over time. Refrigerant is a gas under pressure (sometimes to 400psi or more) so it has to be sealed. You can run into situations where hoses and seals deteriorate over time and cause minor leaks. These leaks may or may not be detectable under vacuum and can only show up after the system hits a certain pressure. Some situations can be seasonal because some owners (as I read on this forum) like to turn the EC switch on over winter to save A/C (save A/C??), thus causing seals to dry up and causing leakage up to a certain pressure. Condensers take a beating while you're driving down the road. Those are example of common exceptions. The more miles you do, the more likely you can pick up a problem (stone in the condenser, worn engine mounts shaking everything loose etc).

It's certainly good practice to check pressures on a regular basis and remedy any problems. If you find your a/c compressor or condenser is covered in oil because of a leak, then it would be prudent to replace it as it will be a matter of time before it fails. If on the other hand , you only see that your pressures are a little low after the winter where the owner refused to turn on the a/c, it's probably o-rings getting dry and you can use your judgment and top the system up

All of this is fine and part of normal maintenance. You're checking the system for problems and remedying them. There's a huge difference between this and my objection. We're not changing oil or rotating tires here.
 
You do hear stories of people who've had cars for 15 years and the A/C still works, but we keep cars in our family for years and if it's not recharged then the a/c generally becomes ineffective around 6-7 years.

In a slightly odd recent experience, the VW dealer did wife's Tiguan FOC at 3 yrs because the service manager checked me in and he said they forget to tell me it should have been done at the previous service! The worksheet had the before and after figures which, from memory where around 450 before and 550 after. However I have read on VW forums some people asserting VW only puts the minimum amount they can get away with then the car is built!
 
However I have read on VW forums some people asserting VW only puts the minimum amount they can get away with then the car is built!

This is very probably not true. Every new car will have a sticker under the bonnet telling you exactly what type of refrigerant to use and how much the system takes. Manufactures won't put less than specified as they designed the system to work most efficiently with these levels, any less or more is not optimal.
 
Phil, I think that what you mean to say is that it is a sealed system where a certain amount of leakage is acceptable over time. Refrigerant is a gas under pressure (sometimes to 400psi or more) so it has to be sealed. You can run into situations where hoses and seals deteriorate over time and cause minor leaks. These leaks may or may not be detectable under vacuum and can only show up after the system hits a certain pressure. Some situations can be seasonal because some owners (as I read on this forum) like to turn the EC switch on over winter to save A/C (save A/C??), thus causing seals to dry up and causing leakage up to a certain pressure. Condensers take a beating while you're driving down the road. Those are example of common exceptions. The more miles you do, the more likely you can pick up a problem (stone in the condenser, worn engine mounts shaking everything loose etc).

It's certainly good practice to check pressures on a regular basis and remedy any problems. If you find your a/c compressor or condenser is covered in oil because of a leak, then it would be prudent to replace it as it will be a matter of time before it fails. If on the other hand , you only see that your pressures are a little low after the winter where the owner refused to turn on the a/c, it's probably o-rings getting dry and you can use your judgment and top the system up

All of this is fine and part of normal maintenance. You're checking the system for problems and remedying them. There's a huge difference between this and my objection. We're not changing oil or rotating tires here.
Yes, I'd liken it to a pressurised engine coolant system (albeit at a much higher pressure of course), where it's sealed, but a very small amount of leakage is expected over a very long period of time.
 

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