Bouncy front suspension

[BrendanM]

I have been putting up with a bouncy front suspension for at least a year.
I have never changed the front spheres on this 1996 XM estate.
Last year I cleaned out the LHM tank and filled it with Hydraurincage flushing fluid.
I am still using it.

I can get the bounce to calm down by moving the height setting lever down to minimum and then up to maximum height for 5 seconds and then back to normal height.
However that trick is not working as well as it used to. On a long journey it seems OK after 30 minutes but plays up if the car is restarted.

This leads me to suspect that the Front height corrector valve is 'sticky'.
I have sprayed oil onto the pivots of the height corrector valve linkages and greased the longitudinal bar that moves them.

Another symptom is that when I turn of the ignition off at the end of a journey, sometimes one side of the front of the car drops suddenly. Could that be a sticking strut?

I have another XM estate which I have kept for spares.

Is it time to remove and service the front height correcting valve?

Many thanks,
Brendan

[Peter.N.]

Sounds like you need new spheres, see if you can bounce the suspension up and down by 4-5" with the engine running, then try it again without, it will not move as much as the centre sphere is not operational but you should still have 2-3", if not the spheres need replacing. To get the original soft ride back change the centre ones as well.

Peter

This post has been edited by Peter.N. on October 12, 2014 03:03 pm

[BrendanM]

The front axle spheres seem to be dated 2006 and the pump accumulator sphere seems to be 2007.

If I am going to buy new spheres I would like them to be the grey painted ones with the long life diaphragm.

Where can I get them from?

I get the impression that some spheres are re-manufactured. Furthermore I am not 100% confident in the description and part numbers listed by the various suppliers.

Hopefully I will identify the Citroen part numbers first and then use these to identify any equivalents offered by the motor factors.

[xmexclusive]

Hi Brendan

The grey colour is industry standard for Nitrogen pressure vessels.
It tells you nothing about the sphere construction.

If you list your XM type I will post the sphere descriptions.
Genuine Citroen green spheres with 3 dimples have the new type membrane.

John

This post has been edited by xmexclusive on October 15, 2014 10:22 pm

[BrendanM]

Thanks John.

It is a 2 litre petrol injection turbo estate with hydractive 2 suspension.

Orga number is 6612 which makes it a December 1994 manufacture. Registered in 1996 I believe.

The parts list I am using says the front axle spheres are 527144 (50Bar 450cm3).

Central 'rigidity regulator' sphere is 95 669 124 (75Bar 450cm3).

AEP use the codes SSXM50FN for the axles and SSXM75FQ for the central sphere.

AEP quote £23.40 and £24.11 (inc VAT) respectively.

[xmexclusive]

Hi Brendan

Have looked them up in the 1995 private cars guide to mechanics.
Size and pressure is the same.
Different Citroen part numbers (probably earlier) are given.
Both types of sphere membrane is shown as M (multilayer) ex factory.
Seems it was in use a lot longer than most of us were aware.
The wheel spheres are shown as having 0.8mm damper.
Codes in book are Wheel sphere 96 222 867, Centre rigidity 96 181 131.

The codes listed by AEP look to be made by IHFS.
A well known reliable sphere supplier that has been around a long time.
Will see if I can check out their website.

John

[xmexclusive]

Looking through some searches to check out this query I noticed an extra feature on matching wheel spheres.
Different makes use different damper design and this can alter the way the sphere behaves in service.
It is therefore best to fit matched spheres of the same make to the wheel cylinders on any one axle.

John

[BrendanM]

I've ordered 3 spheres from AEP.

I will let you know how it works out.

Many thanks for your help.

[BrendanM]

The new spheres should arrive next week but the bouncing was getting worse.

The existing spheres on the front struts are N54328 which might be 'Comfort' spheres for my estate car. They are also marked 08-06--06 which I assume is the date.

The front spheres on my scrap car are older than that and I did not intend to use them.
However I took them off the scrap car and found that they are stamped with the Citroen logo and have 3 dimples. The part numbers are 96 222 867. They also have ink markings FE and 7-163.
They are stamped 50, D1 and M43. I assume the 50 refers to the pressure in Bars.

I replaced the right hand side sphere with the older Citroen sphere and took it for a drive.

The bouncing has gone. The right hand seems a little firmer than the left.

When I turned off the ignition the car did not drop on one side at the front.

It is possible that I have replaced a faulty sphere with a better one.

Another theoretical possibility is that the de-pressurisation procedure has 'fixed' a fault.

Has anyone fixed a fault by simply de-pressurising and then re-pressurising the hydraulic system?

[kenhall1202]

Not really a fault but air in the suspension hydraulics after repair work is commonly removed by performing 'Citroebics'.
This simply consists of raising and lowering the suspension to its maximum extents for several cycles.

I'm not surprised that a dimpled Citroen sphere improved matters - these spheres with the multilayer diaphragms are very long lived due to the much lower nitrogen leak rate.

Ken

This post has been edited by kenhall1202 on October 18, 2014 06:42 pm

[xmexclusive]

I am with Ken on this, dimpled spheres last well with low leakage.
I now pressure test any sphere that I intend to use before I fit it.
It has led to a lot of reuse rather than buying new.

John