C5 X7 centre sphere

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C5 X7 centre sphere

Post by AtleG »

I don’t feel that the ride of my C5 X7 (2009, 2.0HDI/140/H3+/200kkm) is as smooth as I would expect. I’m of course influenced by a long life with other Citroen’s (CX, GS, GSA, older C5), but still. It’s bumpy over speed humps, especially the front axle. And it doesn’t quite have the “flow” on normal roads, it feels like the car doesn’t settle after a vertical movement, but keeps on moving up and down a bit too long, like being at sea. I think it helps with “Sport Mode”.
I’ve measured the pressure in the two front suspension spheres and one of the aft regulator speres, and they are OK. Should I suspect the front regulator sphere?

Two more questions:
-What is the best way to access the front regulator/centre (Hydroactive) sphere? From underneath, or from behind the left wheel? Do I need special tools? I normally use a huge pipe wrench. It looks inaccessible, and I would expect to use great force. Do I loosen it with hydraulic pressure on, and then depressurize and unscrew?
-On the LHM-spheres, it is possible to install a “valve”, in order to check the pressure and possibly refill nitrogen. Is this also an option on the LDS-spheres?

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Re: C5 X7 centre sphere

Post by GiveMeABreak »

If sport mode is making an obvious difference then that would indicate the centre spheres are doing their job. The front and rear centre spheres cut out in sport mode so you ride on the 4 corner spheres providing the firmer ride. In normal or comfort mode the centre spheres are also active allowing all 7 spheres to come into play, providing the more floaty ride. If the centre spheres were not working or low on gas, you would be getting more of a firmer ride all the time, not a floaty ride.

The spheres on these are ultra long life due to their multilayer membrane construction unlike the earlier ones and are not designed to be regassed. As for the front firmness regulator sphere, this is generally removed with the subframe off to get proper access, but this doesn't sound like your issue as the ride you describe is softer and not firmer.....

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Re: C5 X7 centre sphere

Post by xantia_v6 »

I would advise checking the part number on the corner spheres currently fitted to the vehicle, it could be that someone has accidentally (or deliberately) fitted the wrong specification of spheres (or perhaps "comfort" spheres), which give the symptoms that you describe.