Viewing 34 posts - 1 through 34 (of 34 total)
  • Car aircon regassing
  • reluctantwrinkly
    Free Member

    My CRV is 3 years old now and at the last 2 services they have pushed for me to have the aircon gas replaced-not repressurised-citing that new gas contains special lubricants which prevent system deterioration over time. Snake oil or fact? I told them no last time.
    I’ve never had it done or been advised to do it on any previous cars (mainly Citroens) and it didn’t seem to cause any problems in up to 10 year old cars. I tend to leave the aircon on full time.
    Any advice from the car bods on here?

    wrecker
    Free Member

    Snake oil. Tell them to do one.

    Marko
    Full Member

    In theory the system absorbs a certain amount of moisture over time and the lubricating oil (that is in suspension in the refrigerant) breaks down over time.

    So a re-gas sucks out the refrigerant and the oil, vacuums down the system to pull all the moisture out and replaces the oil with fresh.

    I recommend a re-gas every other year.

    Hth
    Marko

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    Gary_M
    Free Member

    Halfords sell an aircon regas kit, anyone tried it. Pressure gauge is £20 which is obviously reusable and the gas is £34.99. With halfords charging £44.99 I’m not sure its worth buying the kit.

    Looks easy to do though.

    JAG
    Full Member

    I’ve recently decided an occasional re-gas is a good thing.

    Mainly after replacing an air-con compressor and finding it was knackered by lack of lubricant caused by losing most of the gas from the system. However the car is 10 years old.

    craigxxl
    Free Member

    Seals do deteriote without the lubricant which will cost you more in the future to fix.
    The halfords recharge kits don’t normally contain enough to refill a car, only top it up. My Mondeo would require 3 cans to fill making it more expensive than paying for a re-gas. I tend to have mine done every 3 years to keep it icey cold. Keep using it over winter to de-mist ensures the system is kept lubricated.

    Frankenstein
    Free Member

    I’ve bought the Halfords gas and a valve kit. £10 surcharge returned on empty bottle.

    If your air con has lost a little pressure over time then this is fine.

    It was a case of finding low pressure valve.
    Attaching like a bike pump.
    Apply pressure like a kitchen trigger cleaner bottle.
    Check gauge and don’t over fill.

    The bottle has gas, sealant and oil. Also safe for garages to extract.

    I will have it all removed professional next spring.

    My old man never uses his aircon in his classic car.
    After 20 years, the rubber seals were dust! Leaks everywhere and aluminium pipes springing leaks.
    Spent 2 weeks of my life dismantling his system and welding random leaks – lucky I had nitrogen spare to use as leak pressure test otherwise garage bill would be 000’s by now.

    If only he kept it serviced :/

    adam_h
    Free Member

    Snake oil. Tell them to do one.

    This. It achieves absolutely nothing. You’re better off just running the a/c regularly through the year to keep abit of oil moving around.

    Gary_M
    Free Member

    I’m probably better getting mine done at kwik fit in that case and maybe topping up annually with the halfords kit.

    bigyinn
    Free Member

    adam_h – Member

    Snake oil. Tell them to do one.

    This. It achieves absolutely nothing. You’re better off just running the a/c regularly through the year to keep abit of oil moving around.
    The lubricants part is not snake oil. They are in there to keep the seals gas tight. I doubt its necessary to it on an annual basis though. I would have though that having the air con on for half an hour once a week would be sufficient.
    Having the system vacuumed and re-gassed every 3 years is probably more than enough.
    Given the cost of a new compressor is probably around £400+ its no bad thing.

    Marko
    Full Member

    The bottle has gas, sealant and oil. Also safe for garages to extract.

    Rumoured to **** up AC machines. If I know somebody has used it I won’t re-gas their AC. Not sure how I’d ever know though 🙁

    This. It achieves absolutely nothing. You’re better off just running the a/c regularly through the year to keep abit of oil moving around.

    Sorry you are incorrect. Just like your engine oil, the oil in the system breaks down over time. The system tends to absorb moisture as well – hence all AC systems have a receiver/drier fitted. As I’ve explained a re-gas will remove the moisture, clean the refrigerant (well filter the bits of crap out of it anyway)and refresh the oil.

    Hth
    Marko

    adam_h
    Free Member

    Sorry you are incorrect. Just like your engine oil, the oil in the system breaks down over time. The system tends to absorb moisture as well – hence all AC systems have a receiver/drier fitted. As I’ve explained a re-gas will remove the moisture, clean the refrigerant (well filter the bits of crap out of it anyway)and refresh the oil.

    So everyone should be getting their domestic fridge/freezers done on a regular basis? Same thing really. You’d never get all the oil out of a car a/c system anyway unless you took off the compressor and poured it out, recovering refrigerant doesn’t pull all the oil out that’s sitting in the bottom of the compressor.

    If it still works, then it doesn’t need touching. The only time I ever see people have issues with car a/c is due to them never using it (compressor seized or o-rings going dry and leaking gas), stones punching holes in condensers or because some Kwikfit type outfit has been messing with it unnecessarily.

    wrecker
    Free Member

    adam h is absolutely correct. Why remove and dispose of refrigerant? Periodic recharges aren’t done on Chillers, fridges or packs; why on car AC? Makes a mockery of the F-Gas regs too.
    This new wonder oil is a new one also, funny that the supermarkets who probably have more refrigeration plant than anyone don’t use it.

    Marko
    Full Member

    So everyone should be getting their domestic fridge/freezers done on a regular basis?

    Nope – not the same. No flexible hoses (the last time I looked) in a domestic fridge therefore not porous.And not the vast multitude of seals and connectors present in a car AC system.

    Why remove and dispose of refrigerant?

    It’s not disposed of, it’s filtered and the correct amount of refrigerant is added to meet the makers specification. In vehicle AC systems a 50 to 100 gram loss per year is sort of acceptable. A system that is low on gas is an inefficient system.

    Makes a mockery of the F-Gas regs too

    How so? It is illegal to re-gas a system with a known leak. Most AC machines will not let you re-gas a system if it will not hold a vacuum.

    This new wonder oil is a new one also, funny that the supermarkets who probably have more refrigeration plant than anyone don’t use it.

    It’s a gas not oil. Same principle for sure, but different operating environments. I’m guessing that somebody worked out that most of the refrigerant lost to atmosphere was coming from motor vehicle and not static systems.

    Hth
    Marko

    molgrips
    Free Member

    So.. after 8 years it’s probably worth getting mine done yes? Left on auto all the time.

    wrecker
    Free Member

    Nope – not the same. No flexible hoses (the last time I looked) in a domestic fridge therefore not porous.And not the vast multitude of seals and connectors present in a car AC system.

    You think that chillers and packs don’t have flexible hoses and vibration eliminators? How do you think LP and HP switches are connected?

    Why remove and dispose of refrigerant?

    It’s not disposed of, it’s filtered and the correct amount of refrigerant is added to meet the makers specification. In vehicle AC systems a 50 to 100 gram loss per year is sort of acceptable. A system that is low on gas is an inefficient system.
    I think you’ll find that if a system gets a regas, the old gas is disposed of. A top up is a different thing. A top up shouldn’t require a machine. A decent engineer will be able to do this without one.

    Makes a mockery of the F-Gas regs too

    How so? It is illegal to re-gas a system with a known leak. Most AC machines will not let you re-gas a system if it will not hold a vacuum.
    Are you suggesting that no gas is lost at all, even during the purging process? It is statute to leak test any system with >3kg of gas which obviously doesn’t include vehicle AC but ripping out gas from a perfectly operating system and recharging is frankly a piss take.

    This new wonder oil is a new one also, funny that the supermarkets who probably have more refrigeration plant than anyone don’t use it.

    It’s a gas not oil. Same principle for sure, but different operating environments. I’m guessing that somebody worked out that most of the refrigerant lost to atmosphere was coming from motor vehicle and not static systems.
    Eh? The OP stated “special lubricant”. Refrigerant gas is not a lubricant, and on top of that, there is no special new refrigerant gas, certainly not one which offers any benefit.
    Most refrigerant loss will also most certainly come from industry, not car AC systems. I am party to refrigerant usage from a major supermarket, and I can assure you it makes for very uncomfortable reading.

    Vehicle AC is tiny stuff. Run your AC every week all year to stop the seals drying out and it should not need regassing at all unless the system has a proper leak. Without the presence of air, oile should not get any moisture and should not need changing. Certainly not every other year.

    Marko
    Full Member

    I think you’ll find that if a system gets a regas, the old gas is disposed of. A top up is a different thing. A top up shouldn’t require a machine. A decent engineer will be able to do this without one.

    Are you suggesting that no gas is lost at all, even during the purging process?

    I think you are confused between static systems and mobile systems. My AC machine recovers all the refrigerant, weighs it, cleans it, gives you the option to add oil (the lubricant), asks you the total capacity of the system (available from the vehicle manufacturer) and then, once it’s satisfied it can hold a vacuum refills the vehicle with the correct amount of refrigerant. Last job is to shut off the hoses and purge them. There is no loss of refrigerant to atmosphere and non to be disposed of.

    Refrigerant gas is not a lubricant, and on top of that, there is no special new refrigerant gas, certainly not one which offers any benefit.

    I don’t think I ever claimed the gas was a lubricant. Look here:

    AC Gas

    We’re now on our third gas for mobile AC systems.

    Without the presence of air, oile should not get any moisture and should not need changing.

    Why do all vehicle AC systems have a receiver/drier fitted then?

    Hth
    Marko

    wrecker
    Free Member

    A receiver and a drier are different things, and just because a filter/drier is fitted, it doesn’t mean that it’s ok to have air in the system. If the system has air in, it will be quite obvious as the compressor will likely eat itself. A presence of moisture would normally be shown by poor (milky) oil in the crankcase, or the moisture indicator on the sight glass showing wet. Not sure how you’d diagnose this in a car AC system. Probably just hook the machine up and do a regas anyway? Do you not ever top up via manifolds?
    Your gas lines will have a residual amount of refrigerant and lose some during the purge, if every car is regassed every 2 years, it adds up to a fair amount. Again, without moisture there is no need for a regas at all.
    A cursory look around internetz shows that the common gas is still R134a, same as has been used in HT refrigeration applications for over a dozen years. Is it likely to move to the propane type gas?

    saladdodger
    Free Member

    Re CRV’s A/C just to give you a heads up

    I have just bought a 2007 crv and the a/c did not work after the first week.
    Kwakfit regas and it was appeared little better so I did a 2.3k drive across france and the a/c was proved not to work
    After a google search I found out there is an issue with the reliability of the a/c control relay ( some folk got ripped off with an a/c compressor replacement needlessly)
    £23 later 2 minutes work A/C is working like a good un

    pacerc200
    Free Member

    There has been talk of hfo1234yf replacing r134a which replaced r12 but cost and availability of 1234yf has put that on hold for the foreseeable future.
    There have been reports of some unscrupulous operators using propane/butane in mobile ac systems if this is recovered by the ac station it causes pretty expensive contamination to the station, there are tester avail that sample the gas before recovery.
    Imagine the fire risk in a frontal collision if propane was used as the refrigerant.

    eskay
    Full Member

    Most domestic fridges/freezers are running constantly.

    Car A/C units run intermittently and as a result the seals can dry out/leak. We have lots of environmental chambers at work that do not run flat out all of the time and the manufacturers always recommend that we run them regularly even if we are not testing anything. This is meant to prevent the seals from drying out (causing the gasses to leak).

    Perhaps that is why automotive systems need re-gassing but domestic appliances do not??

    wrecker
    Free Member

    Propane has been and is used in car AC. There are no recorded cases of explosion (even if there were, its only a few hundred grams). As I expect you are aware, it is used extensively in domestic refrigeration (again zero recorded cases of explosion).
    I was very sceptical and still wouldn’t like to see it used on split type systems but it is very efficient and has a fraction of the ODP and GWP of the traditional refrigerants. I’m not saying it’s the answer, there are far more knowledgable people than me out there but it is an option.

    Frankenstein
    Free Member

    Marko – Member
    The bottle has gas, sealant and oil. Also safe for garages to extract.
    Rumoured to **** up AC machines. If I know somebody has used it I won’t re-gas their AC. Not sure how I’d ever know though
    This. It achieves absolutely nothing. You’re better off just running the a/c regularly through the year to keep abit of oil moving around.
    Sorry you are incorrect. Just like your engine oil, the oil in the system breaks down over time. The system tends to absorb moisture as well – hence all AC systems have a receiver/drier fitted. As I’ve explained a re-gas will remove the moisture, clean the refrigerant (well filter the bits of crap out of it anyway)and refresh the oil.
    Hth
    Marko
    POSTED 7 HOURS AGO # REPORT-POST

    Halfords gas will not mess up aircon machines.
    That only happens with polymer gas units.
    Halfords gas is safe to top up or extract in the the future by a machine.
    Check the instructions on the bottle you buy! It will state if it can be extracted by machines.

    Need a new pusher fan now…dam it! I hate working on aircon.

    pacerc200
    Free Member

    Interesting to note that propane has and is used in cars, do you know which manufacturers?
    The odp and gwp of the new gas was the driving force behind it, not exact figures but it was something like
    1234yf – 5
    R134a – 1000
    R12 – 10000
    Propane would be a very low cost product.

    hegdehog
    Free Member

    It can get quite complicated if you go into detail, but from the information you’ve given definitely snake oil..

    You should only need to add additional oil to the system if there has been a loss of oil somewhere. This can either be from a large or persistent leak, or the replacement of a major component, like a condenser coil or compressor. If you have lost oil in some way, you’re then in the situation of- how much have you lost, so how much do you need to add? This is a bit of a guessing game!

    There is a mechanical seal on the compressor that relies on a thin film of oil to ensure a seal. Periodically running the system throughout the year is the main reason in order to stop this seal ‘drying out’..
    You a/c should automatically kick-in when you put the settings to demist/defrost the windscreen, this is because the cooling effect in the coil will dehumidify the air.

    R134a is not the most efficient refrigerant, but it’s very ‘safe’ to use. Anybody got an inhaler? check the label, you might be surprised by the propellant! 😉

    The oil used is a polyolester & like brake fluid is hygroscopic, so can spoil if exposed to air..

    I’d steer well clear of the self charging cans, the amount of refrigerant in the system is crucial. How would you know if your putting the correct amount in?
    Also if you have a leak don’t touch the leak sealing additives can things with a sh1tty stick & try to avoid the dyes unless you’ve run out of options. A good ac engineer should be able to find most leaks without a dye..

    jota180
    Free Member

    All seems a bit complicated

    The AC stopped working in my car so I took it to the local college
    Half an hour later and at a cost of one packet of chocolate digestives, it was working again.

    At no time did I feel the need to have a physics/chemistry discussion with them 🙂

    If your AC stops working, get it gassed, see if your local college want guinea pigs

    wrecker
    Free Member

    Interesting to note that propane has and is used in cars, do you know which manufacturers?

    I don’t I’m afraid. From what I remember it was in the USA.

    hegdehog
    Free Member

    Propane/Butane blends can be used as a retro-fit gas for R12, although for me the risk of fire from a front end smash is too high.

    I thought one of the concerns with R1234yf was also its flamability?

    If your ac stops working & there’s no gas in the system, make sure whoever does the work carries out a proper pressure leak test with nitrogen, or nitrgen/helium mix.

    The amount of times i’ve seen people have a ‘re-gas’ then a couple of days later it’s not working again due to an un-diagnosed leak is scandalous.

    spartacus63
    Free Member

    Hi
    there’s some real bull been talked in this thread,
    I have 35 years of experiance in the automotive repair industry inc ac work
    fact one ….. vehicle ac systems are not the same as fixed systems as fitted to fridges and freezers tho similar in operating principle, fridges do not have rubber flexible hoses and are not subject to long periods of inactivity thrown about jolted over rough roads heated and chilled to extreme temperature. The rubber hoses allow gas loss and moisture absorption that combined with seals drying out through inactivity mean it is essential to maintain these systems by at the very least removing cleaning drying the gas and reinstalling with the correct quantity id say every 2 to 3 years
    fact two ….. Top up ac gas cans, useless how can you know how much gas is in the system, pressure is no indication as the pressure in the system is related to the temperature. it is vital that the system has the correct amount of gas in order to operate efficiently too much can damage your compressor. it is also illegal in most countries to knowingly add gas to a leaking system,(natural loss should be very small) large gas loss indicates a leak
    Also by the way Most fast fit type operations dont have the skills and knowledge required to work on these systems dont use em end of
    oh and wreker your wrong the old gas gets re used re installed i have never disposed of any gas apart from that contaminated with spurious gas and wreker a top up cannot be done you cannot know how much gas is in the system without taking it out and installing the correct amount, don’t say check pressure because when dealing with refrigerant gasses pressure is related to temperature and is only effected by volume ant the extremes of empty and full for example a 7 kg tank of gas with 6 kg will have the same pressure as the same tank with one kg in at the same temp alter the temp of the gas and the pressure will alter
    sorry forgot now where i was going with this so i hope the info is use full to some one

    oh and wreker no we dont loose gas from the line as its reclaimed before we disconect just shut the valves off vacuum the lines the gas is back in the tank tho yes the will poss be some gas lost on the cleaning process through the auto machine im told this is very small

    Waderider
    Free Member

    So says the man with the vested interest in re-gassing.

    Never regassed a car and no problems. My 13 year old Volvo being the current example.

    Can anyone explain to me how moisture passes through a rubber hose? Please?

    And if your refrigerant disappears, how did it get out? Fix the leak before you refill. No point in just recharging because the problem will still be there.

    Marko
    Full Member

    Can anyone explain to me how moisture passes through a rubber hose? Please?

    They deteriorate over time and become porous. Never had a hydraulic brake hose leak on your car?

    Also due to the grain structure of aluminium you can have micro leaks through the pipework etc.

    That’s why every AC system has a receiver/drier fitted – to absorb moisture.
    Hth
    Marko

    mc
    Free Member

    Car A/C regassing falls under the header of preventative maintenance, with the typical recommendation to get it done every 2-3 years.

    Modern car A/C systems should be perfectly sealed (as part of the EU type approval they are not allowed any leaks over the test period), and provided the system remains pressurised, then no moisture should enter the system.

    Vacuuming is done for two reasons. First is as a basic leak test (as has been mentioned above, it is illegal to gas a knowingly leaking system), and secondly to draw out any moisture that may of entered the system (on a system that’s never been depressurised or open to the environment, this should not be a problem).

    Vehicle A/C systems should nearly always be regassed by weight, as the quantity of gas is reasonably critical to achieve optimum system performance. Too much or too little gas and you won’t get maximum cooling, and risk damaging components.

    As for oil, unless something has gone wrong, it never gets changed or topped up. Some may get drawn out during the regas process, but it should be replenished like for like.

    Air con is like lots of things vehicle related. Lots of myths and facts quoted by those who don’t actually understand the systems, and even more myths by those who have a vested interest.

    suburbanreuben
    Free Member

    Never had a hydraulic brake hose leak on your car?

    Nope, Never, in 35 years of running old crocks…

    bruneep
    Full Member

    well mrs b’s old clio (56 plate) a/c wasn’t cooling, took a trip to halfords they hooked it up to machine and 1 hr later it was regased and I was £49.99 the lighter and it now works. Shes happy therefore I’m happy.

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