407 leaking air conditioning advice please

[Wolds407]

Can anybody advise on the most likely points where air conditioning leaks can develop on a Peugeot 407?

I took a 2011 407 SW 2.0 HDi under my wing last year and have only just got round to trying to sort the air conditioning. A recharge at Kwik Fit was aborted straight away (yesterday) as they suspected a leak and weren't licensed to go further. A specialist that they recommended confirmed a leak but could not find it straight away after an hour and a half on his rig, so he has put in some dye and pressurised it and will look again for me in a few days...

So far I can see no obvious signs of dye seeping out anywhere...

I've just cleared a lot of old leaves out between the cooling fans and the condenser. They'd clearly been there a long time but from what I can see the condenser doesn't look bad.

Last year I spent a lot of time clearing leaves and detritus out beneath the windscreen scuttle, removed the choked cabin filter and thoroughly vacuumed out the filter housing. The car had probably lived under cherry trees or in the woods! The ventilation improved hugely (and the centre screen doesn't reboot so often ) but no cold air

After the specialist put in the dye yesterday, I did, for the first time, hear and then watch the air conditioning compressor cutting in but, as there is no refrigerant, there's no cold air. I've put the climate control to LO and the blowers belt out but to little avail.

What I do notice (or maybe imagine becasuse I'm listening for a leak?) when I switch the engine off is a hissing sound that seems to come from above the centre vents. It fades away quickly but that worries me...

I've looked at my Service Box diagrams and procedures so I understand where the connections are and what nightmares could unfold if I need to get things out from underneath and behind the fascia...

Does anyone have any pointers on where the prime suspects might be? I'd really appreciate your thoughts.

Thanks
Wolds407

[GiveMeABreak]

The dye is a UV dye, so you won't see it without the appropriate equipment to detect ultra violet.

Apart from the condenser, which is very common for a leak due to stone chip damage, there are the valves, the seals, pipes and pipe connections and of course the evaporator box inside the dash as suspects.

A professional should also have a 'sniffer' (like a Geiger counter but for refrigerant gas) to help locate leaks - which has a probe, so they can check inside the car vents for places like the evaporator I mentioned.

My mobile chap had all this kit and spent an hour + checking for a leak on our old C3 - and there were none - so put it down to a bodged refill last year by ATS Only cost me £70 for a full mobile service, test, vacuum, sanitise and refill.

[Wolds407]

Thanks Marc. I think my professional thought the leaks must be big enough to let drips of dye out. It's pretty bright in the bottle but he will be going over it with his UV torch. I don't think a sniffer will work as the refrigerant was long gone and he used something inert to raise some pressure... He seems a great chap and I'm keeping my fingers crossed.

It's annoying that so much of the front end of the 407 has to come off just to get at the condenser. My 406s were so much simpler. If it's anything inside the car I'll need to take some deep breaths before tackling that.

I wonder if anyone is aware of problems with interior component leaks?

[407]

Any final outcome on this one as I have a leak somewhere ?

regards