Grey / Multilayer Spheres ???

mezuk04 · Post by **mezuk04** » 20 Jul 2006, 09:29

In reference to the above, what are these 'grey' spheres that I have heard of and can 'multilayer' spheres be used instead of the normal green ones which for example we use on the Xantia's?

AndersDK · Post by **AndersDK** » 20 Jul 2006, 12:32

Donno if multilayer spheres are coloured grey for identification.
The multilayer designation tells you that the membrane is more than a single rubber composite membrane - presumely lasting a lot longer and with less diffusion allowance.
Note that diffusion always takes place. There is no finite measure against that.

If the sphere otherwise fits the requirements : inflation pressure, filling volume and damping rate - its a direct swap. There are no "new inventions" to the gas constant and damping rate of the damper valve. These must do their job as always since the first sphere constructed by Citroen.

406 V6 · Post by **406 V6** » 20 Jul 2006, 12:53

MEzuk, C5/C6 use the grey spheres. This coloration is different to separate LDS from LHM spheres, as they are not compatible. Mind you, i've heard (or read on this forum) once that later Xantiae had similar spheres, but it's a supposition.

Clogzz · Post by **Clogzz** » 20 Jul 2006, 13:15

The multilayered spheres last about 10 years and have 3 dimples as an attempt to defeat the regassers.
The Xantia has them at the front, while the rubbery ones, called 'Urepan' are at the back.

mezuk04 · Post by **mezuk04** » 20 Jul 2006, 14:59

So for example a grey sphere (multilayered sphere) be fitted to a MK 1 Xantia?

If not, why not?

If yes, why?

Just thought I would get all your cells working

Kowalski · Post by **Kowalski** » 20 Jul 2006, 15:10

I'm just paraphrasing what has been posted above...

A GREEN multilayered sphere can be fitted to the front of a Xantia, the green colour indicates that they are LHM compatible

A GREY multilayered sphere can be fitted to a C5/C6, the grey colour indicates that they are non-LHM compatible and must be used in an LDS system rather than LHM.

The green multilayered spheres appeared on newer Xantias, I'm not sure when they first appeared but they are functionally identical to the non-multilayered spheres they just last longer. If you've got single layered membrane spheres on your Xantia you can replace them with GREEN mutli layered membrane spheres.

Clogzz · Post by **Clogzz** » 20 Jul 2006, 15:14

Think that the grey spheres have an ovoid shape, wider and flatter, and won’t fit for lack of room.
Also, as per Francisco, they are not meant for LHM.
As it is, the front of the Xantia has the green, round multilayered spheres.

Edit: Oops !

Sorry, Kowalski, I sent my story before I saw your post.
The 1995 Xantia already has the multilayered spheres as original fitment at the front.

mezuk04 · Post by **mezuk04** » 20 Jul 2006, 15:23

Ah, I see (its the heat you know, hmm what about winter, ah its the cold you know

)

One un-intelligent wonder, I wonder why they opted for grey, they could have gone for a nice blue.

Thanks guys!

406 V6 · Post by **406 V6** » 20 Jul 2006, 16:46

They could have chosen orange. Green LHM ->green spheres, Orange LDS-> orange spheres. But then again, it would be a "kinky" colour for a sphere

Kowalski · Post by **Kowalski** » 20 Jul 2006, 17:06

There is probably a valid technical reason why the spheres are grey and not orange, something like the chief engineer's wife didn't like the colour

Perhaps they're making them grey so they don't stand out so much and the next step will be that they disappear completely.

rossnunn · Post by **rossnunn** » 20 Jul 2006, 18:35

but if they didn't want them to stand out why not make them black?

I wondered if it was a anti-rusting paint as I noticed a couple of green spheres having surface rust on them.

Thinking about it maybe they're not black due to possible heat soak??

Mandrake · Post by **Mandrake** » 20 Jul 2006, 20:45

The GREEN multilayered spheres with 3 dimples were available for the front on Xantia's right from the beginning in 1993, but they weren't used in all regions or on all cars.

The data books I have show both multilayer and non-multilayer spheres (for the front) were available right through the production run of the Xantia and the part codes for them.

Presumably various economic and environmental conditions dictated whether they were supplied with a given car in a given region...(one thing I've heard is that the multilayer spheres don't like really COLD sub-zero conditions due to the diaphram becoming more brittle at those temperatures so perhaps weren't available in very cold climates)

To get around that problem in the C5 spheres they made them short and fat to minimize the amount of flexing/rolling in the diaphram that might damage them in cold conditions..

Regards,
Simon

slim123 · Post by **slim123** » 20 Jul 2006, 23:23

The green multilayer sphere was used on the Xantia and some XM models, poss as a test bench for the material.

This test was not 100% succesfull as they did fail (lots of em) If you cut open a failed one you will find a black diaphragm, this is made up of 2 x layers of "rubber" with a clear plastic sandwiched between them.

The constant flexing during use made the plastic work harden and crack, causing complete sudden failure,

Of course only fitting these to the front end would mean a quick and easy warranty job, keeping the customer happy, but telling Citroen a lot about the material used.

The same diaphragm make up is used in the grey C5 sphere, but with the sphere being flatter, the flexing is no where near as bad so the sphere works fime.

Diffusion will still take place but it will be a much slower proccess as the molecular structure of the plastic is finer than that of rubber.

BUT....... Cut open a knackered C5 sphere and you will find 3 sharp tangs, hanging down from the top..... the purpose of these?? to puncture the diaphragm and make sure that the sphere is not recharged.

Regards
Slim

jgra1 · Post by **jgra1** » 21 Jul 2006, 00:28

its late and i am tired but...

Slim, you know your stuff I think

mezuk04 · Post by **mezuk04** » 21 Jul 2006, 09:02

slim123 wrote: BUT....... Cut open a knackered C5 sphere and you will find 3 sharp tangs, hanging down from the top..... the purpose of these?? to puncture the diaphragm and make sure that the sphere is not recharged.

Cheeky buggers