Air Con Slow Leak Detection

[Toms306]

I'm out of ideas for leak detection now...

I've cured one medium leak on the system by replacing the condenser (also comes with new drier) and a lower pipe.

It was held on vac test for an hour and showed no drop in pressure at all. 3 weeks later the system has just dropped enough pressure to stop the compressor coming on.

Obviously this is a very small leak, and I can't see any dye anywhere around the system with a UV light.

Is there any other way to find a very slow leak apart from leak dye? Wondered if there was some sort of 'sniff' test similar to an emissions probe?

Also, has anyone tried the DIY leak sealer in a can? Or is there a professional type at AC specialists? I'm not a fan of sealers as they can just block pipes but as it's such a small leak I'm not sure how else I'll find it.

[Magenta Sunset]

the condenser's the one next the rad? yes?
possible pin hole in the heater unit?

[Toms306]

Condenser is the air con radiator yeah, changed that for a brand new Nissens one.

I'm dreading it being a problem with the evaporator (cooling matrix) as I doubt the dash out is an easy job on these. However I would think I'd smell it in the cabin if it was leaking there...though that may be clutching at straws lol.

[Magenta Sunset]

I gather it's a real sod.
other than a failed hose or joint it could be tricky.
was the lower pipe you changed the ones under the bumper? I had both of those changed due to corrosion.

[Toms306]

I gather it's a real sod.
other than a failed hose or joint it could be tricky.
was the lower pipe you changed the ones under the bumper? I had both of those changed due to corrosion.

This is for a Focus, not a 306, but yeah it was the lower pipe under the bumper, seemed to have a manufacturing flaw where the connector was originally pressed on so may never have worked from the factory lol! The pipe itself was fine, it hangs loose so doesn't get the dissimilar metal corrosion that the 306 ones do.

[Magenta Sunset]

Focus - - - my bad

[C2K]

Uv dye is the only way, call an air con man tbh.

Any unions to tighten, any perished seals?

Any mild steel bolts holding pipes together or clamped?

[Toms306]

Can't afford to pay an AC man unfortunately. Garage that originally gassed it can't see any UV dye either, also filled it with Nitrogen and couldn't find a leak. Obviously they can only look outside though, so looking more like it's behind the dash. They just advised that I ask the dealer for any common faults...of course Ford say there are no common faults...they also say the mk3s don't suffer with water leaks yet every one has a pond in the boot.

I don't know how long the system has been out of action for so could be a small split in a dried-out O-ring somewhere yeah, not on the condenser though as they were new. No mild steel bolts on these.

[DeeTurbo]

Can you get access to the compressor pump?

Just thinking it could be that what's leaking?

Is there no information on the Ford forums?

[Toms306]

Can you get access to the compressor pump?

Just thinking it could be that what's leaking?

Is there no information on the Ford forums?

Yeah good access to the compressor, no dye around there either.

No info on the Ford forums as people don't bother fixing AC out of warranty, most of the Mk3 Focus' have broken AC (bear in mind they are only 3-6 years old!) but people give up after the first regas leaks rather than diagnosing it due to costs. I wish I'd done the same now tbh, naively thought it couldn't be anything more than a stone through the condenser at that age/mileage.

[Magenta Sunset]

any of these images any use Tom?

https://www.google.co.uk/search?ei=p3znW...j1b7vXmu-8

[Toms306]

any of these images any use Tom?

https://www.google.co.uk/search?ei=p3znW...j1b7vXmu-8

Not unless they can pinpoint my leak...

I've already traced the system, pipes are all easily visible around the engine bay with the front bumper and undertray off...easiest bumper removal ever btw, no jacking up needed and only 5 mins to remove now I've done it 4 times lol. It's just the pipes behind the dash I can't see.

Am giving up anyway and selling the car, not just because of the AC though lol.

[Magenta Sunset]

nothing beats 'passing the buck'!