Sloppy Xantia Rear End

[ChrisXantia]

Good Afternoon,

A new xantia X2 (non hydractive with anti-sink) onwer here (unfortunately the ownership is new, not the Xantia!).

I have replaced all 5 spheres with new Febi ones, except the Accumulator, which is an I.F.H.S (no idea when it was changed, but i dont hear any frequent clicking).

The car in general feels good, with very good body control.
The rear end height is very sloppy with height changes, as well as when the car stops.
Also, when i turn the car off and lock it, the rear end drops a couple of inches.

I have tried to find a cause though reading all the archive (every single post here is of unlimited value, thank you very much), but I am not sure if the anti-sink sphere is wrong (i cannot find any Febi catalogues in order to ensure the correct one is installed), or if the Accumulator sphere is just in its last legs.

Even if the Febi spheres are the correct ones, are they of decent quality, or i have to look to import I.F.H.S. ones?

Tank you in advance

[xantia_v6]

Height adjustment problems are never caused by bad spheres, the spheres look after the dynamics, the height correctors do the static correction.

It is likely that your suspension is behaving normally, when you stop the car and get out the suspension rises due to your weight exiting the car, and after a few seconds the height correctors lower the suspension to its normal position.

Sloppy height correction is usually caused by stickiness of the height corrector cradles, but air in the hydraulics can cause the rear end to move around more than usual.

[ChrisXantia]

Height adjustment problems are never caused by bad spheres, the spheres look after the dynamics, the height correctors do the static correction.

It is likely that your suspension is behaving normally, when you stop the car and get out the suspension rises due to your weight exiting the car, and after a few seconds the height correctors lower the suspension to its normal position.

Sloppy height correction is usually caused by stickiness of the height corrector cradles, but air in the hydraulics can cause the rear end to move around more than usual.

Hello,
Thank you for the reply.

I did try to remove air from the brake circuit, as I the brakes have some delay to give full pressure. But as others have said, maybe I will have to give each corner much more time, in order to remove all the air from the system.
Does the presence of air in the system also cause the rear to sometimes drop completely when stopped?

Also, my thought to a faulty accumulator sphere was made because the rear stays low on uphill, and high on downhills... but the presence of air in the system sounds very plausible.

[Stickyfinger]

Hi

Have you owned a hydraulic Citroen before >> ?? ...I ask because we need to understand how much "base" knowledge you have.
(for example, you do not bleed brakes in the same way as a "normal" car)

Accumulator spheres are VERY important, esp so with Steering/brakes

IMO, I would look at checking the height correct first

NEVER go under a XANTIA without it being on stands or ramps, esp when working on the suspension...they can kill you if they decide to drop.

[xantia_v6]

You also need to understand the interactions between the suspension and brakes.

If the suspension was neutral, the rear of the car would rise and the front of the car would dive under braking, but the suspension geometry is designed to (more or less) keep the car level under braking.

This does have some side effects. If the front brakes are working more efficiently than the rear, the rear will rise under braking and vice versa.

Also the wheelbase of the car changes slightly as the rear suspension goes up and down, so if the car is stationary and the brakes are applied with the suspension not in its neutral position, the brakes hold the car in that stance, which the height correctors will fight, causing the rear suspension to jolt upward or downward when the brakes are released.

This is all normal, but is exaggerated if there is any air in the suspension or braking circuits.

[ChrisXantia]

Hello Again.

I am pretty convinced that the system needs a thourough bleeding. From the information I found the sequence is: FL->FR->RL->RR. My confusion is regarding the quantity. Do I have to bleed around 2-3 lts in total, or per corner (so I have to get the proper amount of new lhm).

Also I am considering to change the Acc Sphere anyway. The slightly concerning thing is, when i brake on a downhill, the rear lifts quite a lot, which makes the corners quite an adventure... This is my first hydro citroen, and thank god I can get info from this forum, and my mechanic uncle (though not a citroen specialist)

[xantia_v6]

I would say that bleeding 100 ml of clean fluid per caliper should be adequate. If air is still in the system after that then you have an air leak in the suction pipe to the pump or a ruptured sphere.

If the rear is rising under braking, then there is an issue with rear brake efficiency, this could be air in the brake lines or sticking calipers or anything else that reduces the grip of the rear brakes. I have had mild lifting of the rear caused by mismatched pad material.

[ChrisXantia]

Hello again wise people!

As I was away from my Xantia (due to work on another car), i decided to also order a new accumulator sphere 62 Bar, in order to complete the set of new spheres before i do another bleed.

Today it just arrrived from the UK (i am in Greece), and its not the one i ordered!

The sphere I received is a Rolls Royce 75 Bar I.F.H.S sphere (53391 30 010 888)

I read in another topic (viewtopic.php?t=20233&start=15), that the 75 bar pressure was mainly for a higher service life of the sphere to the Roller's.
Is it going to create any issues if install it to my xantia? "xantia X2 (non hydractive with anti-sink)"

Thank you in advance
Chris

[xantia_v6]

I don't think that the extra pressure in the accumulator sphere will cause a problem, when running the hydraulic pressure is significantly higher than that. The useful volume of the sphere will be reduced a little.