W124 Aircon leak

[GP801]

Ok so I am now out in Italy. Its quite warm and the Aircon has packed up. It was recharged last summer and I was told no leaks at that time. Just been to the local mechanic and there is absolutely no gas remaining. He is the one that charged it up last year and remembers doing the job. So its certainly leaking somewhere. Going back tomorrow for more investigation. He seems a decent sort but I would like some information as to any common sources of leaks on 124 systems prior to going back. My Italian is adequate but I could easily be baffled by technical Italian.

 

[bolide]

Condensor and evaporator are the usual suspects. You can source either for around £90 online. Fitting for the former is about 1.5 hours, for the latter about 1.5 days

Nick Froome

 

[jaymanek]

The system isnt too complicated. If the Condensor and Drier are original, they will need doing.
Parts are readily available.

On my car I had to replace the pipework in the engine bay too as it was leaking. That was £600 for the part alone

 

[GP801]

I expect they are original. Quick update. The automatic machine did not detect anything amiss and so it has been recharged and is now working fine. There must however be a small leak somewhere. He seems optimistic that it will last until I bring it back to the UK later in the year. If it empties over the summer months he says he will top it up free of charge just to tide it over.
Thanks for your help folks

 

[jaymanek]

If its a slow leak and the machine hasnt detected a leak on its cycle, then id siggest it could be as simple as leaking from one of the many joins/connections.
Ive even seen them with the valves in the charging ports loose.

 

[JC220]

It would be very useful to have added UV die into the A/C system- do you know if that was done this time? (Since there is a leak suspected)

IF the system leaks empty again it should be possible to pin point the exact leak source (s)with a UV Lamp.

Lots of folks also have success with A/C leak seal additives - in particular for a very small leak like yours appears to be.

 

[vijilants]

Even if there is a leak in the condenser, they do always work for a while until there is no gas left.

As said, you need to have the system injected with dye and then look for the leak.

More often than not, it tends to be a leaking condenser due to age or debris build up rotting out the bottom of it, but the surefire way of finding it is UV dye.

 

[GP801]

We did talk about doing a dye test. The main problem being that I am flying back to the UK on Sunday and not returning until early July. If it is empty then I shall get them to check it properly with a view to curing it. It lasted 8 months on the last recharge so I might get away with it. That way Olly and Jack at PCS can sort it out as usual. Inevitably with this car its always the most expensive option that fails so I expect this will be the same.
Having said that its running perfectly. Just been up to northern Italy to take part in a cycle event and it ran faultlessly and gets lots of compliments from strangers.

 

[GP801]

Quick update. Back in Italy and car was booked in to be fixed. The gas has all gone after 8 weeks unused. They cannot find a leak! Done the dye, used special light etc - nothing. Apparently they are getting a specialist to test it tomorrow under high pressure.Does this sound right? Presumably looking for a very small leak. Also are there any gas carrying pipes or components behind the firewall or behind the dash?

 

[WDB124066]

May be try an Ultrasonic leak detection specialist. YouTube it for the details of the method...

 

[Denis O]

My Smart had a minor leak and all gas would go over a 8 month period. I decided to try a sealant like this https://www.google.gr/search?q=airc...=T79jWafCEofdgAb9uY_QDw#imgrc=ZuTx5YjqM1stsM:

3 years later it's working perfectly so it's a really cheap and effective fix.

 

[roadhog]

Also are there any gas carrying pipes or components behind the firewall or behind the dash?

There's a heat exchanger under the dash and pipework leading to it from the compressor via an expansion valve between the firewalls.

 

[GP801]

There's a heat exchanger under the dash and pipework leading to it from the compressor via an expansion valve between the firewalls.

Thanks for that. Thats what I was afraid of. The dash has been out so many times for other reasons. Oh well we will have to see what tomorrow brings. In the mean time running around in a Smart For 4 automatic. Not quite a 124!

 

[GP801]

Well some good news, some not so good. Used some sort of electronic sniffer device. Condenser, evaporator and compressor are all fine. Two leaks. One from the filling valves and another from behind the dashboard. They have replaced the valves. Not surprisingly they are reluctant to take the dashboard out. So we will I've with it and see how long it lasts. If it sees the summer out then thats fine and I can get PCS to sort the rest when its back in the UK for the winter

 

[GP801]

Just a quick update and request for more advice. Just brought the car back to the UK. Just over 1,000 miles in 24hrs with no problems. The gas seems to have lasted until now although I suspect its not quite as good as it was. The leak is clearly pretty minimal then. What are the expert views on these leak stop solutions for AC systems. Given the leak is so tiny are they likely to work? Are they likely to damage any other components. If it saves removing the dash I am inclined to give one a try. All thought gratefully received.

 

[cheddar]

It’s just like putting rad-weld in your cooling system, not really a good idea, more like a bodge to get shot of a car.
If you are keeping it, it’s far better to have it fixed properly.
If it does need an evaporator, it’s best left to whoever has had the dash out before, it helps having experience of a job like that.

 

[alabbasi]

What year is your W124? If it's older than 1993, then it's a converted R12 system. R12 has larger molecules and did not require barrier hoses. If you're still running R12 hoses, you'll have a very slow leak when running R134a. You should also run a/c regularly to avoid drying out the o-rings. Find a local shop to pull a vac & charge it, then enjoy your holiday.

 

[GP801]

Thanks folks. Its a 1995 with R134 system from the factory. Certainly plan to keep another couple of years so probably best to do it properly.