How much for an XM/Xantia Accumulator?

[Clogzz]

Is it just the front suspension spheres that get the triple membranes?

From what my mechanic told me, yes.
The reason is that these spheres are much more resistant to heat, as there is at the top of the engine compartment.
He also said that they had used these spheres in Africa for 20 years, because it gets so hot there that the black rubbery membranes, 'urepan' ?, were turning to goo in the heat.
The rear spheres are living in the shade and breeze under the car, where it's a lot cooler.

He showed me a black rubbery membrane that had turned to goo when new from the box, never used.
Since he still had it, it meant that the supplier didn't question it, and didn't need it back.
From my dealings in spare parts, that's a sure sign that the occurrence is quite common.

As for why your XM UK S2 doesn't have the dimpled spheres, possibly that some vintages sold in temperate countries came like that, or that they got replaced since.

 

[Mandrake]

From what my mechanic told me, yes.

Yes, according to my sphere list, only the front strut spheres ever came as multilayer diaphrams - not rear spheres and not hydractive centres either.

The reason is that these spheres are much more resistant to heat, as there is at the top of the engine compartment.
He also said that they had used these spheres in Africa for 20 years, because it gets so hot there that the black rubbery membranes, 'urepan' ?, were turning to goo in the heat.
The rear spheres are living in the shade and breeze under the car, where it's a lot cooler.

He showed me a black rubbery membrane that had turned to goo when new from the box, never used.
Since he still had it, it meant that the supplier didn't question it, and didn't need it back.
From my dealings in spare parts, that's a sure sign that the occurrence is quite common.

Thats very interesting.... As well as Urepan there was also Desmopan. Both are trademarked synthetic materials I've managed to find on the net but can't find much info about their properties.

It looks like they use the different diaphrams in different climates, then. The multilayer spheres according to shanes information don't like cold climates, and the Urepan ones don't like heat.

As for why your XM UK S2 doesn't have the dimpled spheres, possibly that some vintages sold in temperate countries came like that, or that they got replaced since.

Yes, or just the fact that its an option. My Citroen sphere tables (genuine Citroen manual) show three alternative spheres for the front spheres of Xantia's - Urepan diaphrams, Desmopan diaphrams, and multilayer diaphrams.

It doesn't make any comments as to which might be sold in which regions and why however, but the climate seems to be as good a reason as any.

Here in New Zealand I've seen both multilayer diaphrams and single layer diaphrams on the front of Xantia's....(without checking the part numbers I don't know if the single layer ones were Urepan or Desmopan though)

Some cars are New Zealand new and many, such as mine, are Japaneese imports, but I havn't noticed a correlation between sphere type and whether they're from NZ or Japan though. I'm also not sure what the climate of Japan is like compared to New Zealand...

Regards,
Simon

 

[sdabel]

Thanks to all for their contributions on this subject- I am certainly learning from it. Checked on PR-net and my car is listed as having:

rear sphere: IMPROVED RR SPHERE
front sphere: UPPER "NOK"
main accumulator sphere: UREPAN ACCUMULATOR SHPERE

Well I now know what the last ones means :wink2:

Looking at my car the rears and main accumulator spheres are dated 2000 so I guess they were replaced at least once in the cars life. The rear ones are comfort spheres. I am guessing that the fronts were replaced at some later time, most likely with what ever was cheapest.

regards
sean

 

[Clogzz]

Hi Simon,

It does look like spheres are marked by temperature range.
I went to the mechanic because the rear of the car had become more bumpy than the front on the rough roads.
There was still springiness in the rear, but with fairly short travel.
The rear spheres were replaced in March 1998, and regassed at least twice since that I can remember.
The pressure in the spheres was so low that he could compress them by pushing with both hands, '25 pounds' he said, say less than 2 bars.
The new spheres are Urepans, out of Citroën boxes saying: très froid, très chaud, meaning 'very cold, very hot', climates.
That is, of course, for within the limits of the 30 bar Urepan rear spheres living in the shade under the car.

Regards,
Terry.

And here for something that I don't know how credible it is, an avatar copied from Planète Citroën forum:

 

[Mandrake]

Hi Simon,

It does look like spheres are marked by temperature range.
I went to the mechanic because the rear of the car had become more bumpy than the front on the rough roads.
There was still springiness in the rear, but with fairly short travel.
The rear spheres were replaced in March 1998, and regassed at least twice since that I can remember.
The pressure in the spheres was so low that he could compress them by pushing with both hands, '25 pounds' he said, say less than 2 bars.
The new spheres are Urepans, out of Citroën boxes saying: très froid, très chaud, meaning 'very cold, very hot', climates.

Interesting, next time I get hold of a sphere box I'll have to try translating it with google

And here for something that I don't know how credible it is, an avatar copied from Planète Citroën forum:

Not sure what you mean by how credible it is ? Thats a diagram of a sphere and suspension cylinder of a DS - you can tell because the sphere is one that can unscrew half way up the sphere, and also the DS used those funny shaped boots - as concertina boots hadn't been invented back then. :joker:

Regards,
Simon

 

[Clogzz]

Not sure what you mean by how credible it is ?

Sorry to cause you that, I should have written properly.
I meant that it’s different and out of scale to anything I had seen of recently, like XM fronts and BX rears.
I couldn’t recognise the DS arrangement because I hadn’t seen it for a long time.

As for translating Citroën boxes from French, if Google arrives with a translation that looks like a language from outer space, you can always enlist me for the translation.
I'm a native of Belgium, and my first language is French.

Haven’t found much about Urepan and its mates either, but here is the little bit that I did find:

http://www.rheinchemie.com/rc.nsf/id/B7B4154E8A9CDDF1C1256E830062D55C

 

[Mandrake]

Sorry to cause you that, I should have written properly.
I meant that it’s different and out of scale to anything I had seen of recently, like XM fronts and BX rears.

Ahh, I see. Yes, it looks fairly close to scale considering its one of those little diagramatic type images that often aren't. Perhaps the cylinder should be a bit longer by proportion but apart from that it looks right.

I couldn’t recognise the DS arrangement because I hadn’t seen it for a long time.

As for translating Citroën boxes from French, if Google arrives with a translation that looks like a language from outer space, you can always enlist me for the translation.
I'm a native of Belgium, and my first language is French.

Thanks, will do. Machine translation is usually only good for a laugh, not getting real information :joker:

Haven’t found much about Urepan and its mates either, but here is the little bit that I did find:

http://www.rheinchemie.com/rc.nsf/id/B7B4154E8A9CDDF1C1256E830062D55C

Yeah, thats about the same kind of information that I've seen... I guess "urepan" is a trademarked material name of a polyeurethane based material.

Interestingly enough I seem to remember dad telling me once that the DS spheres originally used nylon for the diaphram (??) not sure I remember correctly or not, but its a reasonable guess that urepan was not around in 1956 (along with a lot of other synthetic plastics and rubbers)

If thats so, I wonder how it compares in terms of porosity, flexibility and temperature range...

Can anyone remember how long genuine original DS spheres lasted between regassing ?

Regards,
Simon

 

[chris]

Early Ds had naughty hydroscopic LHS inside their hydraulic systems, remember. Lots of potential diaphragm materials probably wouldn't like that...

Chris

 

[Mandrake]

Early Ds had naughty hydroscopic LHS inside their hydraulic systems, remember. Lots of potential diaphragm materials probably wouldn't like that...

Chris

Ah yes I forgot about LHS on the early models... I was thinking of the later DS's which had LHM.

At one point Dad had some green (LHM) DS spheres on the front of his GS which worked very well with the gas pressure and damper valve adjusted to suit. They still had the removable damper valve and the split housing like the earlier ones. It's these ones I'm wondering about the diaphram material, as they were used with LHM...

Regards,
Simon

 

[DoubleChevron]

Ah yes I forgot about LHS on the early models... I was thinking of the later DS's which had LHM.

At one point Dad had some green (LHM) DS spheres on the front of his GS which worked very well with the gas pressure and damper valve adjusted to suit. They still had the removable damper valve and the split housing like the earlier ones. It's these ones I'm wondering about the diaphram material, as they were used with LHM...

Regards,
Simon

That was a remarkable feat .... You see they will not fit the DS spheres being much bigger

seeya,
Shane L.

 

[Mandrake]

That was a remarkable feat .... You see they will not fit the DS spheres being much bigger

seeya,
Shane L.

Huh ?

Have you tried it Shane ? I can assure you they fit perfectly. There is plenty of room around the top of the front suspension cylinders in a GS for wider or taller spheres.


The rear spheres though are another matter entirely. :wink2:

Regards,
Simon