MR2 Roadster Owners Club

The Workshop => Maintenance, Problems & Troubleshooting => Topic started by: shnazzle on July 25, 2016, 16:12

Title: Airconditioning Servicing - Do you do it?
Post by: shnazzle on July 25, 2016, 16:12
I just had my AC serviced and figured it might be worth a post to highlight why this needs to be part of your semi-routine maintenance schedule.

This should be done approximately every 2 years (believe it or not) for maximum performance maintenance. You can of course wait longer. You probably won't notice much difference in year 3, and by year 4 you're used to the new lower performance...so you can see how aircons can go 10 years without a service.

A full AC service should take an hour or so:
- Evacuate the AC system of its contents
- Check for leaks
- Fill with new refrigerant and oil (amount for the MR2 is about 500g of R-134a refrigerant)
- check pressures on low and hi pressure sides. Should be between 1.5-2.5 kgf/cm2 and 14-16 kgf/cm2 respectively after refill.
- Check temperatures of the vents before and after the service

Your AC (if you have it of course) is filled with two things: liquid refrigerant and oil. The former you probably considered, but it also has oil to keep the compressor lubricated. Rather important.
It is a completely sealed system.

Over time the refrigerant (R-134a) in the system is lost (up to 20% per year) and the compressor needs to work much harder to compress the vapor that will quickly evaporate and cause the refrigeration effect.
So, you're getting a very low return for a hell of a lot of strain on your AC compressor. Obviously, this leads to damage. A damaged compressor could lead to it locking up, the belt snapping or worse...causing damage by putting strain on the other pulleys in the system. That's worst case scenario of course.

You can get kits in Halfords that let you re-gas your aircon and fill it up again. But, remember there is oil in there as well that degrades. So I would not recommend using these for each service, maybe every other one.
Title: Re: Airconditioning Servicing - Do you do it?
Post by: Carolyn on July 25, 2016, 17:46
OK.  You've talked me into it.  How much is reasonable?
Title: Re: Airconditioning Servicing - Do you do it?
Post by: shnazzle on July 25, 2016, 17:50
40-50 is reasonable but sometimes there are deals as low as 25 at Halfords.
Halfords one is fully automated but not as involved.

Sent from my SM-N9005 using Tapatalk
Title: Re: Airconditioning Servicing - Do you do it?
Post by: onion86 on July 25, 2016, 17:53
I was actually going to get mine done in the next few weeks, is the oil going to be something you actually get with something like this https://www.groupon.co.uk/deals/ryans-garage-22 as they tend to just say 're-gas'?
Title: Re: Airconditioning Servicing - Do you do it?
Post by: Essex2Visuvesi on July 25, 2016, 18:21
Oil is part of the regassing process

They should also perform a leak test depending on the car this can take up to an hour.

ATS Euromaster were doing the same offer through groupon last month.
Title: Re: Airconditioning Servicing - Do you do it?
Post by: cabbydave on July 25, 2016, 19:05
You cannot evac the system with a diy kit from Halfords. Most a/c machines will add any oil removed when it evac's and vac checks I normally check a system for 20 minutes and always add oil if I have changed a pipe condenser drier or pump. With the machines they have nower days even a quick fit noddy cannot get it wrong worse thing they can do is break the clips on the frunk cover getting to the a/c ports that are next to the spare wheel well. I  moved my fuse box out of the way to make it easier to get the fittings on to recharge the ac.
Title: Re: Airconditioning Servicing - Do you do it?
Post by: shnazzle on July 25, 2016, 19:55
Questions answered above  s:) :) s:)   Thanks youz.

Oh, I forgot to mention the most important part; my AC is now freezing cold since I had it serviced  s:) :) s:)  

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Title: Re: Airconditioning Servicing - Do you do it?
Post by: onion86 on July 25, 2016, 20:19
Cheers all. I'll grab that Groupon then and use the £10 off code, £18.95 is a bargain  s:D :D s:D
Title: Re: Airconditioning Servicing - Do you do it?
Post by: Essex2Visuvesi on July 25, 2016, 20:39
Quote from: "onion86"Cheers all. I'll grab that Groupon then and use the £10 off code, £18.95 is a bargain  s:D :D s:D

Thats what I did with ATS  s:) :) s:)  Bargain of the month  s:) :) s:)
Title: Re: Airconditioning Servicing - Do you do it?
Post by: Jon_G on July 25, 2016, 21:20
The evacuation isn't a reliable leak test, it's to boil off any moisture and other contaminants... A proper leak test requires the system to be pressurised with an inert gas. My Accord 'passed' the vac test last year, but lost all its gas within a week due to poor o-ring seals on the condenser.

But that Groupon offer is pretty impressive!
Title: Re: Airconditioning Servicing - Do you do it?
Post by: MR Roadie 2 on July 25, 2016, 21:39
Got mine done in December through Groupon for £20. I am guessing the garage was quite at that time of year. On the plus side, my wife paid for it as part of my Christmas. Might test the water this year and tell her that my turbo kit (which I don't have) has blown and I need a new one.   s:twisted: :twisted: s:twisted:
Title: Re: Airconditioning Servicing - Do you do it?
Post by: Essex2Visuvesi on July 25, 2016, 21:44
Quote from: "Jon_G"The evacuation isn't a reliable leak test, it's to boil off any moisture and other contaminants... A proper leak test requires the system to be pressurised with an inert gas. My Accord 'passed' the vac test last year, but lost all its gas within a week due to poor o-ring seals on the condenser.

But that Groupon offer is pretty impressive!

A leakdown test was done by ATS

From what I understand they pressurise the system at over the working pressure and leave it for a length of time (30 mins for the Alfa 147) If there is a variance in pressure then it's a fail and they will not recharge the system
Title: Re: Airconditioning Servicing - Do you do it?
Post by: cabbydave on July 25, 2016, 21:49
Quote from: "Jon_G"The evacuation isn't a reliable leak test, it's to boil off any moisture and other contaminants... A proper leak test requires the system to be pressurised with an inert gas. My Accord 'passed' the vac test last year, but lost all its gas within a week due to poor o-ring seals on the condenser.

But that Groupon offer is pretty impressive!
They mustn't have left it under a vacuum for long enough then
Title: Re: Airconditioning Servicing - Do you do it?
Post by: Jon_G on July 25, 2016, 21:50
It isn't anything to do with how long it was left, it's how seals respond to vacuum versus pressure.
Title: Re: Airconditioning Servicing - Do you do it?
Post by: Jon_G on July 25, 2016, 21:51
Quote from: "Essex2Visuvesi"
Quote from: "Jon_G"The evacuation isn't a reliable leak test, it's to boil off any moisture and other contaminants... A proper leak test requires the system to be pressurised with an inert gas. My Accord 'passed' the vac test last year, but lost all its gas within a week due to poor o-ring seals on the condenser.

But that Groupon offer is pretty impressive!

A leakdown test was done by ATS

From what I understand they pressurise the system at over the working pressure and leave it for a length of time (30 mins for the Alfa 147) If there is a variance in pressure then it's a fail and they will not recharge the system
That's a proper test!
Title: Re: Airconditioning Servicing - Do you do it?
Post by: shnazzle on July 25, 2016, 22:19
The one I went to did the proper test. Pressurise and leave it for up to an hour. That's why they say, if it takes less than an hour, they haven't done it right.

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Title: Re: Airconditioning Servicing - Do you do it?
Post by: 1979scotte on July 26, 2016, 06:52
I would like mine done but my AC rad is toast so i will probably remove the system from the car.
Eventually.
Title: Re: Airconditioning Servicing - Do you do it?
Post by: The Other Stu on July 26, 2016, 20:27
I don't have it. Someone said IIRC it was pretty easy to retrofit?
Title: Re: Airconditioning Servicing - Do you do it?
Post by: Jiff Lemon on July 27, 2016, 16:18
Mine is done every 2 years. The guy that does it said to keep an eye on the pipe where it goes along the near side chassis leg; apparently that's the common failure point.
Title: Re: Airconditioning Servicing - Do you do it?
Post by: Rockingdad on July 28, 2016, 22:46
Quote from: "Jiff Lemon"Mine is done every 2 years. The guy that does it said to keep an eye on the pipe where it goes along the near side chassis leg; apparently that's the common failure point.

Sorry to be a bit of a noob here but where are you talking about? I'm trying to trace the leak on mine. Had it UV dye filled with the refill after I bought it, leaked out in a few days. Cant find it with a UV torch anywhere!

Cheers

RockingDad
Title: Re: Airconditioning Servicing - Do you do it?
Post by: barchetta_ms on May 9, 2021, 10:51
Sorry to revive an old thread - I'm replacing the condenser and it has come with a small tin of oil. Does this go in when I fit the condenser or when I have it re-gassed? If it goes in with the condenser, where do I add it?
Title: Re: Airconditioning Servicing - Do you do it?
Post by: rusty0273 on May 9, 2021, 16:26
I got the same little tin when I changed my condenser. When I went to get it regassed the aircon guys (ATS on Groupon voucher) asked about oil and upon checking the tin, said its exactly the same stuff they use routinely. Pretty sure its to be added when you get it re-gassed. Its for the compressor rather than the condenser.
I assume its supplied in case you are re-gassing yourself using tins. Not sure if that's even legal these days.
Unfortunately, although my system is now sealed with no leaks, mine has an issue with the compressor to be addressed now.
Title: Re: Airconditioning Servicing - Do you do it?
Post by: Frank Rabbets on May 9, 2021, 17:21
Whenever a part of the AC system is replaced some oil is lost as there is no sump to collect it. It's all over the system. There should be a guide in the Factory WSM to tell you how much to add for replacement of each component. A myth is that these new machines add the "right" amount of oil to top up the system but they can't and don't. They weigh the oil that comes out (say 10%) and add that back in. This all assumes the correct amount is in there in the first place. If one has a leak somewhere it's best to add the recommended amount of oil for the replacement part then some more to compensate for the leak. It's only possible to remove all the oil by stripping all components down and washing through.
The compressor spindle seal can leak if you can't find a leak with a UV light in amore obvious place. Difficult to get in there. Can one use a mirror with UV light?
My 06 reg AC is still going strong but there is little resistance in turning the spindle so probo needs regassing.
Title: Re: Airconditioning Servicing - Do you do it?
Post by: barchetta_ms on May 9, 2021, 17:28
Thanks both
Title: Re: Airconditioning Servicing - Do you do it?
Post by: rusty0273 on May 10, 2021, 10:51
Quote from: Frank Rabbets on May  9, 2021, 17:21Whenever a part of the AC system is replaced some oil is lost as there is no sump to collect it. It's all over the system. There should be a guide in the Factory WSM to tell you how much to add for replacement of each component. A myth is that these new machines add the "right" amount of oil to top up the system but they can't and don't. They weigh the oil that comes out (say 10%) and add that back in. This all assumes the correct amount is in there in the first place. If one has a leak somewhere it's best to add the recommended amount of oil for the replacement part then some more to compensate for the leak. It's only possible to remove all the oil by stripping all components down and washing through.
The compressor spindle seal can leak if you can't find a leak with a UV light in amore obvious place. Difficult to get in there. Can one use a mirror with UV light?
My 06 reg AC is still going strong but there is little resistance in turning the spindle so probo needs regassing.
That's interesting. I'll be sure to ask for the additional oil to be included when I finally get my system sorted out. Thanks.
Title: Re: Airconditioning Servicing - Do you do it?
Post by: Frank Rabbets on May 10, 2021, 21:41
Incidentally there might well be a safety switch to cut the electrical power to the compressor clutch in the event of pressure falling too low. The gas circulates the oil around the system. If the compressor runs with no oil it seizes. I've seen several seized compressors caused by not replacing oil when several components have been changed over the years.
Title: Re: Airconditioning Servicing - Do you do it?
Post by: Gaz mr-s on May 10, 2021, 21:58
My old pfl has a/c, & it will give 'cool' but not really cold air....it's not something I use, but I should maintain it, & I have this saved in my ebay stuff.  https://www.ebay.co.uk/itm/353097782283?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

No mention of oil.  Worth buying or not?