MORE SUSPENSION QUESTIONS :) xantia turbo diesel saloon

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citronut
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Post by citronut »

it can also be refered to as the regulater sphere
regards malcolm
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Post by slim123 »

Or the green ball thing at the front !!!!!

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vsx

Post by MATTT »

mine is a vsx so what are the extra 2 spheres for then?
theres one right on the rad at the front

also ive just picked up the new main accumulator one and checked but theres no new seal in the box
i guess its ok to reuse the old one?

also one post says set car low and the other on high b4 replacing it ?


Matt
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Post by AndersDK »

The most basic setup - ever since the D series - have 5 spheres total on the car.

The suspension sphere for each wheel is obvious - and attached to the suspension strut itself.
That makes 4 spheres.

Then there is the system accumulator sphere - which accumulates system pressure to avoid rapid minor fluctuations in the system pressure - while the hydraulic pump is running - and some pressure is consumed.
This sphere is always attached to the pressure regulatro - which in turn is always attached to the engine/gearbox assembly.
It looks then like the accumulator sphere is attached to the engine/gearbox - always - no matter hydraulic Citroen model.
The accumulator sphere is also referred to as - main sphere, main accumulator sphere, main system sphere, system sphere etc. - as it provides the basic source of a ready pressure.
That makes 5 spheres - and is the basic setup since the hydropnumatic Citroen was born.

Models with antisink system then have an extra sphere fitted under the rear of the car. This is designated the anti-sink sphere. As it is there in necessity to provide the rear brakes with an accumulated pressure should - the engine (and therefore pump) stall - it is also referred to as the rear accumulator or the brakes accumulator sphere.
That makes 6 spheres.

VSX models are fitted with hydractive suspension. This suspension type has an extra rigidity sphere for each axle. The system is best identified by the drivers switch to select suspension mode - and the large dia (10mm) rigid piping from the axle sphere - running to the wheel spheres.

On front the hydractive sphere appears to be attached to the radiator - or somewhere else on a chassis memebr - just NEVER on the engine :!:
There is a good reason for this : the engine is allowed to "float" a bit by its rubber mountings to provide for a smooth drive. This would really fast break the 10mm dia rigid pipings from the hydractive sphere.
That makes 7 spheres.

On rear the the hydractive sphere is fitted to the rear crossmember - again identified by its 10mm large dia piping running to the wheel spheres.
That makes 8 spheres.

Now only remains the ACTIVA special version of the Xantia. Not to be confused with the common hydractive version.
The ACTIVA has (hence its name) active anti rool bars - by introdung a ram cylinder in the arb. This needs a separate ready accumulated pressure to act rather fast when entering a turn. If this pressure was to be taken from the main accumulator - this would very fast be exhausted from accumulated pressure making the pump working overtime - and the active ARB appearing to collapse.
The activa spheres are fitted un the subframe close to the arb. One at front and one at rear.
That makes 10 spheres in total on the Xantia Activa model.
Anders (DK) - '90 BX16Image
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Post by andmcit »

Just to confirm for you before you end up being sprayed in high pressure LHM whilst you change your accumulator sphere!! To depressurise the car all the fluid needs to be returned to the reservoir by using the height adjustment lever to the minimum height.

As yours is the VSX with the extra centre sphere at either end the pressure will released from these by running the car in the low setting for about two minutes.

The VSX spheres effectively allow a variation in the damping effect of the suspension movement by increasing/decreasing their volume by valves electronically cutting in and out. The ride of a well sorted VSX is simply amazing - You'll know if the car needs new centre spheres as the car wont be a floaty merely relying on the outer corner spheres.

YEP USE THE OLD PROPER SQUARE SECTION SEAL - smear loose fluid on as Malcolm says!

Have fun and whilst youre getting messed up, check your strut tops... :)

Andrew
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Post by slim123 »

If you are only changing the main accumulator, there is no need to depressurise the suspension, this will stay up fine as it is locked off by the height correctors, you only need to slacken the regulator bleed screw.

But as a safety measure it is allways a good idea to shove a couple of stands under a car before venturing under it's belly.

You can completely remove the main accumulator and the regulator if you desire and the car will not fall from it's heigh position, well after a few days with internal seepage it may !!!!

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Slim
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Post by Mandrake »

AndersDK wrote:Now only remains the ACTIVA special version of the Xantia. Not to be confused with the common hydractive version.
The ACTIVA has (hence its name) active anti rool bars - by introdung a ram cylinder in the arb. This needs a separate ready accumulated pressure to act rather fast when entering a turn. If this pressure was to be taken from the main accumulator - this would very fast be exhausted from accumulated pressure making the pump working overtime - and the active ARB appearing to collapse.
The activa spheres are fitted un the subframe close to the arb. One at front and one at rear.
That makes 10 spheres in total on the Xantia Activa model.
That doesn't quite tell the full story of the Activa - there are indeed two extra spheres, one at the front and one at the back, but they serve very different purposes. (They are not simply for front and rear anti-roll rams)

The one at the front is in fact mounted on its own on the gearbox and has a built in pipe union like an anti-sink sphere, and is as you say an additional accumulator sphere to provide intantaneous pressure supply to the anti-roll system alone, and is thus not consumed by brakes or normal height correction.

If this sphere is faulty the response of the anti-roll system will be slowed down preventing the anti-roll system responding quickly enough.

The Activa sphere at the rear on the other hand is mounted on the Activa regulator which is very similar to a normal Hydractive regulator block but with some internal differences. (Like no anti-roll blocking ball valve)

The outputs from either side of this unit are piped to one side respectively of the front and rear anti-roll rams, and together with the input pressure on the other side of each ram the rams are therefore connected in a loop sharing the same Activa sphere at the rear.

When the rear Activa sphere is switched out during cornering the front and rear anti-roll rams resist roll because they are connected such that they push against each other during roll leaving the (stiff) rollbar stiffness as the only flexibility.

Furthermore the roll corrector can inject or remove oil volume from the coupling between the two anti-roll rams, causing both anti-roll rams to expand or contract by an equal amount in such a direction to counteract the body roll.

With the Activa sphere enabled the springing provided by the sphere makes BOTH the front and rear rollbars effectively softer than they really are allowing easier independant wheel movement and better ride. If this sphere is faulty the rollbars will be in "stiff mode" all the time causing a lot more fidgety ride.

The important points are the front Activa sphere is an accumulator sphere for the entire anti-roll system, while the rear Activa sphere is the rollbar stiffness regulator shared by both front and rear rams.

Regards,
Simon
Simon

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SORTED

Post by MATTT »

well
theres a lot of bits but ive learnt a lot as to how it all works

fitted the main acc sphere yesterday and no more clicking :)

just put it on high and unscrewed the 12mm pressure screw,although i didnt actually hear a thing as in escapings pressure hiss.It leaked a small amount but nothing to worry about,the red indicator is still inbetween the 2 lines on the guage,the fluid was clear and green
i reused the old seal as you dont get a new one from euro when you order the sphere.
lubricated the back height linkage and it all seems to be working fine

now for the cruchy syncromesh on 3rd......

thanks for all the helpful and detailed replies
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Re: SORTED

Post by AndersDK »

MATTT wrote:now for the cruchy syncromesh on 3rd......
Set the suspension to highest.
Stop engine, block wheels, jack up and support the weight of car.
Drain gearoil.
Clean the outside of the gearbox housing.
Working from LHS wheelarch - unscrew end cover.
Withdraw main shaft and layshaft.
Replace 3.rd gear syncromesh units.
Reassembly is the rev.....

Now thats easy aint it :lol:
Anders (DK) - '90 BX16Image
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scary

Post by MATTT »

sounds prety scary to me
think i might just put up with it!
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Post by jgra1 »

my GSF sphere had a seal in a hidden comartment in the box... bit late now but worth checking?

John
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