Xantia Sphere Change (Mk II)

littleredrooster · Post by **littleredrooster** » 17 Apr 2005, 23:17

Got the Xantia a couple of weeks back ('01 HDi, 96k miles) and am delighted with it. Got the headlights adjusted properly with the help of you guys, now am thinking about replacing the front spheres.
Quick question first: Is it possible to determine how much pressure is in the spheres before I change 'em?
I only ask because the Xantia doesn't have that 'magic carpet' ride that I remember from my old BX some years ago. The front seems quite 'firm', for want of a better description. The rear, in contrast, seems to soak up everything in the road without passing it to the cabin.
So, have I got this right (if I decide to change the front spheres)?
I loosen the spheres a touch with the suspension in the highest poition, then lower the car and de-pressurise via the bolt on the accumulator (behind the radiator?). Unscrew the spheres and replace with new, start engine and pressurise back to normal ride height, bleeding if necessary (the car, not me!)
Any mileage in replacing the accumulator sphere at the same time? Will this stop my brakes from doing a slow 'pulse' when braking from high speed?
Thanks, chaps!

Post by **user_3150** » 17 Apr 2005, 23:52

Spot on with the removal I would do the accumulator as well as It's not very expensive £18 from GSF. Also do some Citerobics when completed to get rid of all the air, also have some kitchen roll ready for leaking lhm from the sphere's. As for the pulsing it's more likley to be the front disk's being warped which is common on Xantias so I would change them as well at some point

AndersDK · Post by **AndersDK** » 18 Apr 2005, 00:01

You cannot determine a pressure figure in the spheres - unless tested on test-jig with a special high pressure gauge.
But you can of course apply common sense.
The hydropneumatic Citroens are no different from other cars in terms of suspension softness when a load is applied on the car.
With engine running and height set to normal drive position - press down each corner.
It should feel soft like any other car.
If rock solid - or a feeling of only rubber (tyres) are tried to be compressed - that corner sphere is (near) flat.
When replacing the suspension spheres :
Have engine running.
Set height to max position.
"Crack" the sphere.
Set height to minimum.
Stop engine and remove sphere.
Only when replacing the accumulator sphere you need to discharge the pressure.
It's wellknown that a flat acc sphere is the cause of all kinds of hydraulic Gremlins.
NOTE : Some descriptions tells to loosen the sphere 1/4 turn with max pressure on suspension. From personal experience this could well make you win the lotteri - LHM spraying at frightening pressure all over [:D]

Kowalski · Post by **Kowalski** » 18 Apr 2005, 04:17

As Anders says, some people will tell you that you have to loosen spheres by 1/4 turn with the suspension fully up.
This ONLY applies to the rear corner spheres and even then only if the suspension cylinders have been turning when you've tried to unscrew the spheres. In this situation I wouldn't recommend as much as 1/4 of a turn, all I'd recommend is to get it to move a tiny amount i.e. break it, then lower and depressurise.

littleredrooster · Post by **littleredrooster** » 18 Apr 2005, 05:14

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Alec

As for the pulsing it's more likley to be the front disk's being warped which is common on Xantias so I would change them as well at some point
<hr height="1" noshade id="quote"></blockquote id="quote">
The 'pulsing' isn't at road-wheel speed - it manifests itself from a stop at high speed where, with constant pressure on the pedal, the brakes initially bite hard then partially release then bite again. This sequence is repeated. Cycle time is about 1 - 1.5 seconds.
According to the service history, the discs were replace about 8000 miles back.
Thanks for the other replies, guys.

alexx · Post by **alexx** » 18 Apr 2005, 14:40

There's no need to set suspension to max height before undoing front and rear corner spheres on Xantia (at least on mkII). They will go easier with depressurised suspension

Post by **Peter.N.** » 18 Apr 2005, 15:09

Does your car have ABS? I had an XM which exhibited the "pulsing when breaking at speed" syndrome, it was due to the fact that somone (me actually) had replaced one of the drive shafts with one of the incorrect type, wrong castelations.

Kowalski · Post by **Kowalski** » 18 Apr 2005, 15:26

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by alexx

There's no need to set suspension to max height before undoing front and rear corner spheres on Xantia (at least on mkII). They will go easier with depressurised suspension
<hr height="1" noshade id="quote"></blockquote id="quote">
The rear suspension cylinders can rotate when you try to remove the spheres and if this happens you can shear off the hydraulic pipe going in to them quite easilly. It depends who put them on, whether they tightened them by hand or used a tool (which is NOT recommended or required) and how rusted up they are. Sometimes you just can't remove the rear spheres without having the cars weight on the suspension cylinders, sometimes you'll need to balast the rear of the car to get them to shift. It DOES happen.

alexx · Post by **alexx** » 18 Apr 2005, 15:49

They won't rotate, becasue they are fixed in place with a piece of metal - there is only a several mm free play in each direction

Kowalski · Post by **Kowalski** » 18 Apr 2005, 15:56

They are held by a piece of metal, but when they are really stuck, that piece of metal bends even though it is quite thick. I have managed to bend this piece of metal on my older Xantia, I decided that since it was bending a new approach was needed before something got badly damaged.
The piece of the cylinder that the hydraulic pipe fits into goes through that same piece of metal, once bent enough it shears the pipe off.

alexx · Post by **alexx** » 18 Apr 2005, 16:41

I agree

mattpc · Post by **mattpc** » 18 Apr 2005, 19:57

might be an idea to do a hydraflush. I had the pulsing you described in mine. When I hydaflushed for 1000 miles and and then put lhm back in the system the problem basically went away.

peter finch · Post by **peter finch** » 08 Oct 2005, 16:04

littleredrooster wrote:Got the Xantia a couple of weeks back ('01 HDi, 96k miles) and am delighted with it. Got the headlights adjusted properly with the help of you guys, now am thinking about replacing the front spheres.
Quick question first: Is it possible to determine how much pressure is in the spheres before I change 'em?
I only ask because the Xantia doesn't have that 'magic carpet' ride that I remember from my old BX some years ago. The front seems quite 'firm', for want of a better description. The rear, in contrast, seems to soak up everything in the road without passing it to the cabin.
So, have I got this right (if I decide to change the front spheres)?
I loosen the spheres a touch with the suspension in the highest poition, then lower the car and de-pressurise via the bolt on the accumulator (behind the radiator?). Unscrew the spheres and replace with new, start engine and pressurise back to normal ride height, bleeding if necessary (the car, not me!)
Any mileage in replacing the accumulator sphere at the same time? Will this stop my brakes from doing a slow 'pulse' when braking from high speed?
Thanks, chaps!

First time I've written anything here, but thank you all for the advice as I was completely stuck- that is the brackets were turning. Then I realised that the brackets tighten up when the engine was restarted, so I checked on this sight that for the rear spheres, the system needs to still be prssurised whilst you slacken them off a little. I also purchased the correct sphere remopval tool which costs around £35=00 and is worth it. The spheres on my current 99 HDi were much tighter than the front ones on my previous 94 model, which I still have as I haven't sorted the pulsing brakes prior to selling it. I will try the system flush, as I have already changed both accumulators, with little benefit.

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Xantia Sphere Change (Mk II)

Xantia Sphere Change (Mk II)

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