C5 MkII aircon failure

[Superaquarama]

Recently bought a s/hand '08 C5 whose aircon didn't work. Under warranty, so took it back & they regassed it and it worked fine - for a few days ! Then in S France realised it wasn't working again, so took to a Citroen garage who checked it over, left a pressure test on it for an hour, declared no leaks, regassed it (and added dye, none visible) and it again worked for a couple of days before dying.

So what can this fault be, that allows the gas to escape, presumably all more or less at once, and yet shows no leaks detected ?

And what's the best way to proceed ? I don't want to keep taking the car back every week (dealer's 30 miles away), so am inclined to ask them to keep it a few days and see what's happening for themselves and only give it back when the aircon's working properly. I'd have thought that, with dye in the system, the leak would be bound to show up somewhere.

Any advice gratefully received !

Otherwise, though, I think it would be very hard to find a better car for a long journey - hums along in near silence at 130kph and in supreme comfort with high 40's economy, 3 up & fully loaded. It's the 2.0HDi Exclusive, by the way, with hydractive suspension.

Anthony

[Lighty]

Thevlow pressure pipe (fat one) out of the compressor is a common failure on these.
There is a Citroen "info rapid" bulletin on it. New pipe £45 + vat, bought one yesterday.
The rubber section disguises a leak well.
Obviously it could be elsewhere, but worth checking.

[Superaquarama]

Many thanks for that, Lighty, will investigate the pipe - do you perchance have a link to that 'info rapide' bulletin ?

I actually spoke to a Citroen UK tech adviser who said there were no out of the ordinary faults on the current C5's aircon !!

[Superaquarama]

When I say MkII, this may not be correct ? I'm talking about the current model.

[wheeler]

The current model is the mk 3.
I think it would be best to get some UV dye in the system, that should show up in no time where the gas is going.
The vaccum test done my the AC machines is not a good indicator that the system is sealed as the system operates under pressure not vaccum, vaccuming can actually seal leaks aswell, giving a false sense that it is ok

[Superaquarama]

Yes, thanks, Wheeler - have spoken to an aircon specialist who said exactly that. Although we do have dye in the system & no sign of it ! Anyway, the dealer has agreed that I can take it to the aircon guys as they've been unable to find the leak, so will get it sorted next week.

[markflip]

I have a 2008 C5 and the pipe from the compressor to the heat exchanger next to the radiator has gone - waiting for that to be fixed this week and hoping that's it cured. Previous owner/dealer must have had it re-gassed and dyed as my air con man (who only uses dye as a last resort) wasn't impressed they'd used it when you could clearly hear/see where it was leaking from as soon as you fired up the pump. Even with such an obvious leak it evacuated perfectly as talked about above. The worst leaks with aircon are where the pipes disappear across/behind the bulkhead, often behind sound baffles etc. My bloke has an electronic 'sniffer' device that can pinpoint even tiny leaks (apparently) and can probe the difficult to get at areas to give a hint if it might be worth 'digging' further.

{edit} the pipe has sprung a leak in the rubber section of hose and it's the thinner of the two pipes attached to the rear of the compressor in my case - I'll update when this is replaced this week, weather forecast doesn't look like the lack of A/C will be a serious concern for a few days at least!

{edit} part is on back order from factory, suggesting these are in demand! But my dealer states the replacement is a modified design so hopefully will last a bit longer. It was 40ish quid plus VAT - it doesn't come with new sealing rings/washers but they were only ~60p each, so as aircon repairs go it's not too bad IMO.

[markflip]

New pipe arrived and cost ~35 quid - it is modified in that the metal section that connects to the compressor is longer and has three bends in it, presumably to cause less flexing/twisting of the rubber section during engine torque reaction? It did come with the 4 x sealing rings in the end and was a doddle to fit - 10 minute job max. Regassed it and A/C now works perfectly

[now just need some decent weather to use it in!!!]

[Animal Mother]

Where is a good place to get the pipe (or get it repaired if it's cheap enough)?

[GiveMeABreak]

This is an old thread (7 years old) Pop your VIN up and identify the pipe you want and I'll get the part number for you