The air conditioning on my latest acquistion doesn't work at all - mind you, I didn't expect it to, really!
As a guess, I'd say a holed condenser, but would any leak detection require re-filling with refrigerant? If it is a leak, then that would seem a bit wasteful! I believe that UV-visible dyes can be used to locate where the problem is.
One thing I'm not sure of - should there be any residual pressure in the system if the compressor is not running?
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im sure i read that meganes of this errer have major problems on the inside of the car and its a fortune to fix as its a dash out
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>>> As a guess I'd say a holed condenser but would any leak detection require re-filling
>> with refrigerant? If it is a leak then that would seem a bit wasteful!
If you take it along to your local Kwikfit, they'll test for leaks before attempting to refill. If any leaks are detected, they won't charge you for the work nor fill the AC system.
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Didn't know KF did aircon re-gassing Dave. Might take the Mondy along for a check up if it's a "while you wait" affair. AC seems to work fine but it's eight years old plus a very miley car and I'm sure it has never been done. Any idea of costs ?
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>> If you take it along to your local Kwikfit they'll test for leaks before attempting
>> to refill. If any leaks are detected they won't charge you for the work nor
>> fill the AC system.
Thanks for that, VxF, but do you know what they fill with? Maybe just air and check that the pressure holds up (though I guess you couldn't pinpoint the leak)?
If the a/c can be made to work reasonably cheaply then that'd be a bonus - but I can always do without. BBQ summer, here we come!
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It's illegal to put refrigerant in a leaking AC system. As part of their routine they go through they test for leaks before refilling.
It's £20 during the winter and £40 during the summer.
It's all done by a machine, all they need to do is choose the right model of car on screen, then follow the pictures on screen to connect to the hi and low service ports for the AC system, then the machine does the rest -- recovering the existing refrigerant, weighing what's been recovered, refilling the right amount of oil and refridgerant according to the database on the machine etc.
It's a steal.
Edit: I think if it recovers less than what should have been retrieved according to the machine's DB, it doesn't refill to what's specified in the DB, it refills to what was recovered +10% -- don't know the logic / reasoning.
Last edited by: CraigP on Mon 19 Apr 10 at 20:01
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>> Thanks for that VxF but do you know what they fill with?
From what I understand they either place the system under vacuum or pressurise it.
Unless they've changed the equipment, this is the sort of thing they use (I'm not responsible for the translation):-
i12.photobucket.com/albums/a246/stargazerplus/robinair.jpg
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>> (I'm not responsible for the translation)
Superb! "Automatic rifles" ... "money laundering"
Maybe a Sicilian manufacturer? :-)
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I installed, serviced, repaired, and trained the users of these machines in Kwik Fits in the south of england a couple of years ago.
It runs through an automatic cycle, advancing to the next when certain criteria have been met.
It checks for positive pressure in the system, if it sees any it will zero it's internal gas bottle scale, and zero the recovered oil bottle scale. Recovery starts, and when it sees a pressure of minus 0.2 bar it stops the recovery and waits for a couple of minutes. If it see pressure rise above zero, it restarts the process. When it sees no pressure rise, it opens it's internal oil seperator into the waste oil bottle for 30 seconds. After that it records the weight increase in its gas tank and oil bottle.
Then it starts the vacuum process for the preset time, usually 30 minutes. After this it monitors the pressure again for a couple of minutes. If it sees a pressure rise of more than 200mbar, it fails the leak test. But.... measuring pressure increase from a vacuum is a poor method of leak testing, as you've only got outside air pressure trying to get in. So this test is generally meaningless unless you have a large leak.
If it passes the 'leak test', it will open up it's 'new oil' bottle to the system and the vacuum in the system will draw in oil until the bottle weigh scale has changed by the correct amount (ie, the amount that it weighed out in the previous oil bottle). After this it refills the system with liquid refrigerant from it's internal tank as set by the vehicle database in the machine. It automatically adds a small amount extra to account for what stays in the charging hoses. When disconnected from the car, it will then recover the charging hoses so they are empty for next time. Then you get a little printout showing - gas recovered, oil recovered, pass/fail leak test, oil charged, gas charged.
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Thanks, Dave, for your excellent description.
One drawback with fully automatic units like this is what happens if the process fails any of the stages. "Dunno, mate" from the spotty apprentice isn't very helpful in this situation :-)
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I had Kwik Fit regas the Scenic's air con which had become completely ineffective (about all that told you it was on was the light on the button).
Paid £40 and got the car back with ice cold air-con. It stayed that way until we sold the car on a year or so later.
As Dave says, the machine generates a nice little report as well telling you before and after parameters relating to various system pressures and temperatures, and the cold air output temperature at the vents. It also tells you the weight of refrigerant recovered and added.
I was well pleased.
Last edited by: DP on Sun 25 Apr 10 at 01:53
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Be careful if getting it done at Kwik Fit, they did my air con but it wasn't working again after a month. I got my money back and went elsewhere.
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>> Be careful if getting it done at Kwik Fit, they did my air con but it wasn't working again after a month.
If the problem with your AC is that you have a slow leak, then a leak detector will not find a leak that takes a month to lose the refrigerant. Can't blame kwikfit for that. At least they honoured their guarantee of a money back refund. Some other places wouldn't.
Put it another way, it's like a slow puncture in a tyre. It might take a week to go flat, it might take a month to go flat, but in the meantime it's still useable.
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>> Put it another way, it's like a slow puncture in a tyre. It might take
>> a week to go flat, it might take a month to go flat, but in
>> the meantime it's still useable.
In that case, it's worth the extra to introduce UV dye into the system. This will show up a slow leak. On my car, you could see an oily residue around the offending area.
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KF were resisting the introduction of dye, as they are only supposed to be recharging fully functioning system. If it's empty when it gets there, they should refuse the work straight away. Some don't though. They didn't want to get into the whole diagnostic and repair business.
Unfortunately, most systems work very well until the break (or leak) completely. It's very very rare that they have a residual loss over a long period of time, such that the system is empty. I know everyone talks about the 'normal' 10% (or whatever) loss each year, but in practice is never happens. If you have no (or very little) gas left, then it's 99.9% certain there's a leak, and any replacement gas willsimply go the same way, and usually fairly quickly. No fancy machines with print outs change this.
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My Nissan lost 40% over eight years. I had it serviced because it wasn't quite as 'sharp' as it had been.
Are you suggesting that rather than a gradual loss over the eight years, I could soon be looking at a total failure as the 40% disappeared relatively recently?
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Any rotating pump with seals will always leak a little gas...
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>> My Nissan lost 40% over eight years. I had it serviced because it wasn't quite
>> as 'sharp' as it had been.
>>
>> Are you suggesting that rather than a gradual loss over the eight years, I could
>> soon be looking at a total failure as the 40% disappeared relatively recently?
>>
I think (though I didn't write his words) that you are misinterpreting Dave's post:
It's very very rare that they have a residual loss over a long period of time, such that the system is empty.
Last edited by: Mapmaker on Wed 25 May 11 at 17:17
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Renault Megane - 01 1.8 Aircon leak detection - Dog
