Citroen C5 X7 mk3 hydractive suspension (updated after fitting new spheres)

[white exec]

You need a larger version of the d.i.y. tool for C5's saucer spheres, which are larger girth than the classic round sphere.
Xantia hydractive (centre) spheres can be saucer-type too.

[Peter.N.]

The C5 spheres have a larger diameter than the Xantia/ XM ones so the purpose made tool has to be the right one.

Peter

[Y Cymro]

A quick post to explain that the dealership had the official Citroen tool to remove spheres but that failed to get it off in situ. I spoke with the workshop manager who knows what he’s doing and told me that a mechanic tried hard to get it off. He explained that the problem is because the solenoid block mount is pressed steel and won’t allow the torque necessary to unscrew the sphere without tearing off. The official Citroen solution is to lower the rear of the front subframe to make space and allow a better attack angle - though if the flimsy mount is the problem I should imagine the block would need to be removed so the sphere can be removed at the bench. The specified time for this is 4 hours, but he explained it could take as little as 2 or perhaps as much as 6, and I’m not prepared to gamble £500 or more without knowing for definite that it will cure the issue.

[white exec]

Did not realise the mounting for the suspension block had been reduced in strength.

They sound as if the know what they're doing.
Might an air chisel dug into the sphere loosen it, without putting continuous strain on the bracket?
A heavy weight (eg a length of steel pipe, end-on) placed against the block could further take the load off the support.

I guess the sphere has been seriously over-tightened at some point, and maybe a non-lubed O-ring too.
Done up hand-tight, they always tighten in service - hence the need for a biff with the removal tool.

Paul (citroenxm) - in Anglesey - might have some advice for you.

[Y Cymro]

They sound as if the know what they're doing.
Might an air chisel dug into the sphere loosen it, without putting continuous strain on the bracket?
A heavy weight (eg a length of steel pipe, end-on) placed against the block could further take the load off the support.

I’m told that due to the position of the sphere it’s possible to get the Citroen removal tool onto the sphere, but not get a chisel on it - and importantly, with no space to swing a hammer. Similarly, there no space to be able to support the pressed steel bracket to allow more torque to be applied to release the sphere. That said, it’s now been flooded with release fluid so perhaps it’ll fall off in a weeks time

[Hell Razor5543]

Flood it daily for the week, to give it the best possible chance of loosening off.

[Y Cymro]

Ok, how does this sound for a plan as I don’t want to keep throwing money at this without one.
The workshop manager in my local dealer has been very helpful and can run diagnostics on my suspension for a fixed £60. My theory is that if it’s the comfort/sport/rigidity solenoids not activating then an error code will be displayed and that can be addressed. Similarly, if there’s a fault elsewhere in the electro-mechanical system then an error should be displayed and that can be the focus for repair (I doubt this would be the case because the suspension seems to work correctly, and the only problem I note is that the front suspension is firm). I believe that faulty spheres don’t trigger error messages, so if no error codes are displayed then the front rigidity/sport/comfort sphere (apologies, don’t know the correct name for it) is faulty and will be replaced.
Sound like a reasonable plan?

[white exec]

Having re-read the complete thread, I think the best (budget) way forward would be to renew the front centre (Hydractive) sphere, and see whether that will provide softness at that end.

Important to get exactly the right sphere (they have no damping - the damping is built into the EV/regulator valve body).

On removing tight spheres, one thing that wasn't mentioned was the importance of relieving all the hydraulic pressure behind a sphere, before attempting to unscrew it. (The spheres are designed to tighten and be leak-free when the system is pressured.) Your Citroen workshop should know the correct de-pressurisation procedure for the system, but in addition to that, and to be sure pressure is gone, the suspension could also be put on lowest, and the hydraulic pipe union from the BSI (see Marc's diagrams) slackened off, to relieve any pressure. I'm not sure what the bleed screw on the valve might do, in the way of relieving pressure behind the sphere.

I do know that a sphere with hydraulic pressure behind it can be seriously hard work to unscrew.

If (and hopefully not) the front sphere remains immovable, then next tactic could be to renew the pair of centre spheres at the back, and see whether that restores Soft there.

After any sphere removal, a good idea to have the system bled of air, by the proper procedure. Air in the suspension can create crashiness all on its own, because it's compressible, and will not operate hydraulic valves correctly.

[Y Cymro]

Excellent, thanks Chris

[GiveMeABreak]

Proper bleeding procedure is here in my other post:
viewtopic.php?p=648493#p648493

[Y Cymro]

Great stuff, thanks Marc
I’ve already followed your bleeding process (!) but unfortunately it wasn’t the fault.

[GiveMeABreak]

[tomassk8]

Great stuff, thanks Marc
I’ve already followed your bleeding process (!) but unfortunately it wasn’t the fault.

Hi. I am dealing with the same problem. I decided to replace the rear comfort spheres because it was easy and I could do it myself, but it didn't make any difference. I want to ask if you solved your problem?

[Y Cymro]

Great stuff, thanks Marc
I’ve already followed your bleeding process (!) but unfortunately it wasn’t the fault.

Hi. I am dealing with the same problem. I decided to replace the rear comfort spheres because it was easy and I could do it myself, but it didn't make any difference. I want to ask if you solved your problem?

My rear spheres were stuck to their support bracket due to galvanic corrosion between the dissimilar metals. Finding a repair was getting expensive so I sold the C5 nearly thee years ago. I’m surprised that changes the spheres didn’t cure your problem though.

[GiveMeABreak]

In some cases it can be the rear hydraulic block that the rear centre spheres are connected to. This controls the operation of the centre spheres and if the electro valves are sticking then it can cause problems, so changing out the rear centres spheres won't make any difference if this is the problem.