C4 grand AC

[Althesandie]

Hi. I have had this Picasso exclusive for years now and since getting it the AC has been a problem Have had it put on the machines at three different garages over the years and despite telling them there is definitely a leak after two to three weeks it does't cool again. Last garage said the vacuum was Ok and no leaks. Just wondering if anybody knows a proper AC specialist in the Newcastle upon Tyne area where I can get this sorted out once and for all. Any help appreciated.

[RichardW]

Quite likely it needs new valves, these obviously don't leak when the machine is connected!

[xantia_v6]

Also bear in mind that a vacuum test is applying 1 bar of pressure, but in normal operation, parts of the system run at 15 to 25 bar, so a vacuum test can miss small leaks.

[Althesandie]

The schraeder valves was my exact thought. Last visit they rang me and said that the vacuum was ok and did I want it gassing up. I said no and the valves were the only thing that made sense to me. He said I will let the mechanic know. Came back and said "Uh, he's already gassed it up but I won't charge you for the gas" Three weeks later hot again.
I never knew that the system ran as high as 15 to 25 bar. I suppose the only way to find it then would be with one of those "Sniffers" or with the dye detector. Wouldn't mind but they also said that the system had some gas left in so it all makes sense.
Just need to find someone who can find it. All the AC specialists just seem to be normal garages with the machine.
Thanks for the replies. It is appreciated.

[xantia_v6]

Try to find someone with a sniffer. Dye can work well, but only if the leak is in a visible location.

If a Schrader valve is leaking, there should be a pressure build up under the dust cap and you will hear a little gas escape if you loosen the gas cap. You can also put a detergent film across the valve opening and see if it forms a bubble.

[Althesandie]

Had it back in for testing and they found everything OK again. They recharged the system for free so I didn't complain. Got it home and took the two caps off. On one of the valves there was residue of what looked like oil they had put in while gassing it up and on watching it for a while there would be a tiny bubble come through. Had bought a cheap sniffer and that registered as well. Have PTFE taped the spigots and put the caps on as tight as I can get them.Six weeks up now and it is still working. Will buy new valves later in the year and get the system topped up
Thanks for the help!

[GiveMeABreak]

Thanks for the update - looks like you found the issue.

[Jcdem+1959]

AC only works for back seat passengers. Suggestions?

[GiveMeABreak]

@Jcdem+1959: Please don't duplicate posts - previous post has been deleted. It causes duplication of answers...

It may be that the Heater Blower Motor has failed at the front.
The Rear system has a separate motor on vehicles with secondary units for rear passengers.