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Discussion Starter · #1 ·
Well, after my recalls were done, I had a look at the Adblue tank cap to see if it had been changed.
Yes, it was different with a white button in the middle of the blue cap. Is it vented via the white cap I asked myself? ..and blew really hard into the cap both ways to no avail. It was well sealed!
Removed the white button to reveal a tapered seat on the blue cap and a brown o ring under the white button.
As neat as this was, it was a really tight seal meaning that the Adblue tank would really need a very high pressure to blow past the brown o ring to vent, so I've removed the o ring and refitted the white button meaning the tank will never pressurise.
If anyone knows a reason why the tank needs a pressure inside it, let me know as I'm told the pressure build up is bad for the tanks pump but right now I can't think of one as a pump would generate it's own pressure.. 馃
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Interesting that it's grey, I thought the replacements were all blue like the originals but with the vented white centre, maybe they changed the design.
 

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Discussion Starter · #4 ·
Update..
I dismantled the white button assembly and discovered a poorly made unit.
Its supposed to allow air into the tank as the pump pumps Adblue out into the injector but is so badly made, it doesn't actually work.
Reason being, is that under the white cap is a wee white diaphragm that, on mine, wasn't properly placed to work as it should.
Remedy? I removed the diaphragm and reassembled the unit including its brown rubber o ring and tested it by creating vacuum from inside the cap with the result that the Adblue cap cap now correctly entrains air into the tank.
Hopefully, this will prevent any issue with the tanks pump.
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Discussion Starter · #5 ·
In summary, just because you have an upgraded tank cap, dont just assume the problem has gone away because if it's anything like mine which was done yesterday under a recall, it's still not fixed and the Adblue tank pump is still at risk..
 

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Nothin wrong with these caps. Citroen reckoned that having a badly working adiglu system was bad enough. A ghost story was circulated ' non operating adiglu systems ' replace the cap, not the tank/pump. It saved them a fortune on recalls/repairs. That's why you cannot get a diesel Cactus (or any) diesel non commercial Citroen passenger car. Strange that inn'it.

I got the software removed, that makes the pump work (don't care if it don't) passed a couple of Mot tests. As the only go by lights saying 'Cactus says nooooooo' to fail it (and the dpf fumes if non operative).

Still puts out the same diesel emissions, adiglu or not. And I believe the cap on top of the goat piss tank was changed before they sold it to me. Still I have some (about 陆 a lire) of watered down adiglu in the tank sloshing about. But it no longer pumps the shi7e in my exhaust.

Ha ha, only filled it with a 陆 litre, in case the adiglu police stop me.:p:p
 

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Interesting. I just removed my updated cap to see how it was. It was air tight. The white diaphragm appeas to once have been able to let air through. But when I inspected it it was air tight. The AdBlue had mad it sticky.
I too removed the white diaphragm and can now confirm that air can pass through the vented cap. Thanks for the post!
 

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Interesting. I just removed my updated cap to see how it was. It was air tight. The white diaphragm appeas to once have been able to let air through. But when I inspected it it was air tight. The AdBlue had mad it sticky.
I too removed the white diaphragm and can now confirm that air can pass through the vented cap. Thanks for the post!
Glad to help.. I hope others have read this and sorted out their own "upgraded" cap.
If yours had crystals, maybe it needs regular checking to keep it clear. Mine was only hours old when I examined it.
I may end up just removing the white button entirely! 馃
 
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