Very Bouncy Ride, Air in the system?

My 1999 V6 Exclusive is apparently sucking air into the suspension, whihc makes the ride very bouncy. A dealer suggested that the hydraulic pump was at fault, but I cannot find any trace of a leak. Has anyone else seen a similar problem?

Its possible the the fluid intake pipe to the pump is cracked, thats about the only way you would get air into the system, but in 20 years and about 10 hydropnumatic cars, I have never experienced that problem. The usual cause of a 'bouncy' ride is duff spheres, when were they last replaced?

Peter.N.

Ther have never been replaced, but the system was bled when I last had the car serviced and that made a tremendous difference, so I assume that their diagnosis is correct. I posted here to get alternative opinions on where the air might be coming from. They suggested replacing the pump (£300!!), but it owuld appear that air is being sucked in elsewhere and the intake does seem the most likely place. Perhaps that means a simple replacement of the intake pipe - I hope.

Hi,
I don't think air in the suspension system can even make it bouncier. Think about it this way, the oil is a sort of transport medium to pressurise your 'springs' which are in fact the nitrogen gas reservoirs enclosed by an elastic membrane (the spheres, add more spheres and thus more gas volume, ie: hydractive, and you can vary the stiffness quite easily ). The reason to use oil as a medium for this is because it is not compressible (don't know if that's a word in english??). If the complete system would be full of air (imaginary, you wouldn't be able to do it with a setup like on the xm) this would only add to the softness of the suspension (more air to compress). So having air in the system doesn't make it bouncier in my opinion. Besides this, the system is self-bleeding. The oil used for the suspension is recycled through the reservoir, allowing any air out and catching debris picked up on the way through means of the filters in the reservoir.
The membranes of the spheres are slightly porous, allowing a little of the nitrogen gas out over time, reducing the pressure. (this gas is let out through the reservoir) when the pressure goes down so does the volume in your 'springs', making the suspension harder.
The only things you can bleed in the system are the brakes, and you certainly don't want air in that.
Get them to replace the spheres (only front if that is bouncy, only rear if that is bouncy or both front and rear. You have three front and three back which are related to the suspension.) I certainly wouldn't replace the pump!

Cheers,
Niek

This post has been edited by Niek on November 06, 2005 09:16 pm

I agree with what Niek says. The spheres only have a life of 60-80k miles, the front ones maybe even less so if your car has done this or more you are well due for a new set. They are not expensive, about £20.00 each form GSF and they will transform the ride.

Peter.N.

Hi

Replace the spheres, it's almost certain they are kackered on a 6 year old car, but the spheres on your 1999 V6 exclusive are particular to that model and you'll have to get them from Citroen, andyspares don't list them.

Cheers

Tony

Oh dear!

Peter.N.

Since it citroen, very dear

£60 each.

Tony

Plaiedes (hope that's spelt correctly) will supply them for a lot less than that.

Derek

This post has been edited by DerekW on November 13, 2005 09:54 pm