Aircon leaking. Where to start?

[Grazinho]

Hi guys

My girlfriends air con has quite a large leak and isnt holding any refrigerant at all. I want to fix it but dont want to spend a fortune as the car isnt worth a great deal.

I have a refrigerant handling license from my work however the systems I work on are different to a car system so I'm wondering what would be the best way to check for the leak. Could I use nitrogren (or even compressed air) and some fairy liquid? Also what are the most common areas for large leaks?

Also I could smell refrigerant from the blower before. Is that an indication the leak is inside the car and not the engine bay?

[finlo]

The condenser will be corroded or stone damaged.

[E-bmw]

Surely, if you hold a refrigerant licence you are familiar with pressure testing as a means of identifying leaks?

[227bhp]

It's unlikely to be inside the car, it's the last place i'd look.
The systems have tracer dye in them, usually yellow/green and you can buy leak detectors, they're a bit like Geiger counters in that you wave them around the system and it beeps when it detects a gas leak. A visual with soapy water is fine too.

[Grazinho]

E-bmw said:

Surely, if you hold a refrigerant licence you are familiar with pressure testing as a means of identifying leaks?

I have the refrigerant handling license. I can handle the refrigerant safely. Ive done a quick pressure test so I know its not holding pressure but Im not sure how to detect exactly where the leak is located?

The systems I work on are different to cars. We use a complex rig with helium to detect leaks. Its not like I can buy that of the shelf (if I could it would be worth more than the car).

Like I said I can handle the refrigerant safely however im not sure how exactly the systems work on a car. Plus the systems I work on tend to be smaller more enclosed units whereas a car will have the components and pipes running through from the front of the engine to behind the dash.

[Grazinho]

227bhp said:

It's unlikely to be inside the car, it's the last place i'd look.
The systems have tracer dye in them, usually yellow/green and you can buy leak detectors, they're a bit like Geiger counters in that you wave them around the system and it beeps when it detects a gas leak. A visual with soapy water is fine too.

Cheers. Ive seen them being used. I dont know exactly how good they are (ie do they just read flow or do they detect the refrigerant) and I dont particularly want to spend a fortune on expensive tools I'll probably never use again.

I might just try the soapy water thing to start. Do the systems usually come with dye in? Ive seen the dye kits on amazon which would probably be my next step after the soapy water?

[E-bmw]

Grazinho said:

E-bmw said:

Surely, if you hold a refrigerant licence you are familiar with pressure testing as a means of identifying leaks?

I have the refrigerant handling license. I can handle the refrigerant safely. Ive done a quick pressure test so I know its not holding pressure but Im not sure how to detect exactly where the leak is located?

You use your senses just the same, a BIG one you will hear, a smaller one can be detected by injecting dye when doing the pressure test, however if you haven't got the kit to do it why not just take it somewhere that has & pay them the usual £30 & they do it all for you.

[Grazinho]

E-bmw said:

You use your senses just the same, a BIG one you will hear, a smaller one can be detected by injecting dye when doing the pressure test, however if you haven't got the kit to do it why not just take it somewhere that has & pay them the usual £30 & they do it all for you.

Most places are £30 just for a regas. I wouldve thought theyd charge a lot more for diagnostics? If not thats a good shout.

Im half tempted to invest in the kit for a bit of cash on the side. I dont know how long it would take to pay for itself and how many cars I could do from one bottle though?

[guards red]

I'd be looking at the condensor in front of the radiator for damage/leaks. Most likely area.

Then the pipies to/from the compressor.

Also check the schrader high and low pressure valves. Not always picked up by pressure trsting as the air con machine connects to these. Fairy liquid here is telling.

Finally, the evaparator inside the car. These can rot depending on the car and it's location. You need some dye/gas in the system to test here, or a professional a/s machine.

[E-bmw]

Grazinho said:

E-bmw said:

You use your senses just the same, a BIG one you will hear, a smaller one can be detected by injecting dye when doing the pressure test, however if you haven't got the kit to do it why not just take it somewhere that has & pay them the usual £30 & they do it all for you.

Most places are £30 just for a regas. I wouldve thought theyd charge a lot more for diagnostics?

I thought you knew about handling refrigerant?

If you did you would know that it is illegal to charge without first doing a pressure test to make sure it doesn't just go straight out into the atmosphere.

Your £30 gets a vac out/test of contents/check for leaks/recharge & system health check.