Suspension Query

Hi everyone ,
some advice please,
I have recently fitted 4 new spheres to my suspension because the ride was becoming uncomfortable .
Now on certain road conditions with just the driver in the car i am getting some jolting , but just when you expect to get jolted it seems fine.
On saturday i had three passengers in the car and drove about 80 miles on A roads and the ride was wonderful any ideas please .
Best regards Bob

yeah change the center spheres or drive in sport mode both should cure your problem.

A'bientot

How old your center spheres are?

Yes, as mentioned on previous posts, the centre spheres are the ones mainly responsible for the 'soft' ride, in fact just changing the centres will have more effect on the ride than the 'corner' ones. Fit new ones and you will be amazed!

Peter.N.

Hi everyone ,thanks for the answers,i have been reading the posts about the hydraulics but seemed to get conflicting information.
So the centre spheres do affect ride comfort /hardness ,i got the impression that they only affected the roll effect when cornering?
But i bow to your experience and will endeavor to get them changed soon,the back one dosent look to bad to do ,what about the front one anyone had an experience of this ?
Thanks again Bob.

Hi Bob,

If all is Ok, the ride should feel excellent in all cases and conditions. It should simply not make you think of the suspension. Getting "jolted" etc. means by 99% that some of the spheres there are low/shot. All spheres together make up for the suspension's comfort. What I found in my case (I had all spheres in bad condition and one front was even shot) is that when spheres are very low on pressure the car's body develops greater width and speed of up/down motion. This makes the body motion sensor on the front antiroll bar energise the hard mode more often than it would normally, so at those moments comfort gets even worse. The thing is that with worn spheres comfort is ok in other circumstances, and awful in others. Having no experience of hydraulic hydractive Citroens before, I was just confused, but the day I fitted new spheres all round the difference in the way the car took each and every bump and hump on the road was amazing. So, best bet is to have new middle spheres as well, and then see.

George

Hi george thanks for the reply,
there is so much info in here its sometimes hard to make any sense of it .
Do you know if noz has a hangover todayafter the shiraz?
Best regards Bob

The centre spheres give most of the suspension movement. When cornering or braking the centre spheres are cut off thus putting the suspension in sport mod, if the centre ones are u/s you will permantly be in sport mode. The corner spheres have very small orifices giving hard damping, the centre ones have a very large orifice, like an accumulator sphere, which is how you get the 'floaty' feeling.

Peter.N.

Hi peter thanks for the info thats cleared up some doubts in my mind ,thanks again.
Best regards Bob

Hi everyone ,purchased my front and rear center spheres on thursday from G.S.F. at 19.50 each . They are different in size ,front one is bigger than rear?
Any comments on this diference F that was the missing F please .
Is the front one a sod to change?
Any advice please on method ,ihave had no problems so far (why did i just say that) i have now changed 5 spheres and all went well .
Thanks in anticipation Bob.

Hi Bob,

Just to clear a few things up. Your problem can be one of two things:
1) Your centre sphere (front or back or both) may be flat and hence no bounce.
2) The electrovalve on the centre sphere may not be opening.
Both would lead to a harsh ride.

More analysis would be required to determine which one it is. Since you've already bought your spheres then you will be able to determine the fault by a process of elimination.

If it turns out to be the spheres then you've replaced them and that will be the end of the matter. However, as I suspect, it is the latter problem especially if it seems that it is intermittent. Search on electrovalves and suspension ecus in this forum to find posts explaining the problem. The freewheel diodes in the electrovalve coils burn out causing the 'transistors' (dont shoot me for the vocabulary) inthe ecu to overheat and fail. It starts intermitently at first gradually getting worse until theres no soft mode at all.

Not sure on your size question. I'm not at home at the moment so can't look up the manual until Sunday at the earliest. Can anyone else look up the suspension section and find the sphere volumes for Bob?

When you look at the neck of your new spheres you won't see any orifices (dampers) at all. Thats because they are built in to the electrovalve unlike wheel spheres. Although the orifice sizes are larger in the middle sphere compared to the wheel spheres its not by much in relative terms.

As to your question on comfort/stiffness/roll they are all controlled by the same mechanism. They are not really differentiated. Any of the measured parameters will trigger the hard mode if the parameter exceeds the set limit. The response is the same no matter what caused it.

The front sphere is no more difficult to replace than the rear. A Pleiades tool is best because the sphere is very close to the chassis and only the thin band of the Pleiades tool can slip through the gap.

Hope that solves some of your confusion at least. Please let us know how you get on.

Cheers

noz

This post has been edited by noz on April 07, 2006 11:08 pm

Hi,

Assuming I'm reading the manual correctly, the front sphere is 450cc at a pressure of either 70 or 75 bars (according to model), the rear sphere is 400cc at 50 bars for the saloon and 500cc at 40 bars for the estate.

Derek

Hi guys thanks to you all for the info.
I am going underneath today ,let you know what happens .
Best regards Bob

Hi sorry to disturb you but I have a little problem.
I have been out and got 6 sphere's for my car in hope of doing the job myself. The problem is my car has 2 front centreal sphere's, ones located behind the rad and the other next to the steering rack. Which one does what? and was I right in buying Accumulator spheres fo the centre suspension?

sorry I know this might sound all daft to you lot but many thanks for any help

Stan

One of the front accumulators is for the suspension (the reaarmost) and the one behind the radiator is the main accumulator. You must have no preessure in the system to be able to change either. The suspension one will be depressurised if you let the engine tick over for about a minute, with no movements of pedals , steering wheel or doors(which will close its open valve). The main accumulator pressure relief is the 11 or 12 mm bolt head on the side of the unit attached to the main accumulator. (One or two turns only) Accumulator spheres are 400cm2 capacity and vary in pressure and internal bore diameter.