Why do new spheres go hard very quickly?

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white exec
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Re: Why do new spheres go hard very quickly?

Post by white exec »

Just to add to the discussion...

Spheres have three (not two) characteristics:
eg 400/50/1.5
The first figure is sphere volume, in cc
The second is gas pressure, in bar (and the higher the pressure, the softer the ride - not harder)
The third is the diameter of the tiny damping apeture in the sphere neck, in mm

So, it is important that a sphere has the correct damping figure.
eg a 400/50/1.1 will present much more resistance to sudden movement/roll than a 400/50/1.7.

Much more serious is failing to distinguish between 400/62/1.5 and 400/62/--.
The latter (one of our Accumulator spheres) contains no damping whatsoever (-- signifies a large open hole), and if fitted to a car's corner would produce a wallowing boat-like ride.

Many of the aftermarket sphere suppliers totally fail to list this final figure in their catalogues. This is just lazy, and makes shopping a bit of a gamble, hoping that their listing is accurate. If spheres go similarly unmarked, checking out a purchase also gets difficult.

For a proper check on the complete (3-way spec) of our suspension spheres, go to the Mechanic's Handbooks which we have posted, where you can see Citroen's three figures for each position on the car.

Genuine Citroen spheres, although more expensive, do at least carry verifyable part numbers, and also benefit from using the extra-durable "triple layer" membranes (for hot areas, such as the engine bay). If you are not replacing spheres very often (or are re-gassing conventional round ones) then buying Citroen originals could be a good investment.
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Re: Why do new spheres go hard very quickly?

Post by GiveMeABreak »

GiveMeABreak wrote:
30 Aug 2019, 15:22
Confirmed this is the correct VIN David. Citroen parts confirm the volumes and pressure for the corner spheres for your C5.

You have an Estate and the DW12ATED4 engine with H3+.
Your Front corner spheres should be 385cc and 52 Bar.
Your rear corner spheres should be 385cc Volume and 31 Bar.
It is the Front Regulator Accumulator sphere that is 385 cc and 62 Bar.
The Rear Regulator Accumulator sphere is 385cc and 45 Bar.

So it is possible that 62 Bar rigidity spheres have been wrongly fitted to the front corners.....Boing said Zeberdee!
@Chris: The damper holes are not specified on the C5 MK I in the mechs handbooks for this year Chris.

So to complete my report above here are the damper hole specs for each:

Front Corners: 0,9 / 0,48
Rear Corners: 1,4 / 0,94
Front / Rear Rigidity Accumulator Spheres: Not specified.
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Re: Why do new spheres go hard very quickly?

Post by white exec »

Marc, can you remind me what the twin damper figures mean?
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Re: Why do new spheres go hard very quickly?

Post by GiveMeABreak »

If you recall we never really got to the bottom of it and of course they no longer specify such settings from the C5 on as it was not really relevant. The soft / firm status is handled by the rigidity / firmness regulators front and rear on H3+ and by the volume of Nitrogen in the spheres generally which vary model by model. There are no damper orifice settings listed now from the MK II on.

I only managed to pull off the data above as it was for a MK I C5 - but no longer listed.
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Re: Why do new spheres go hard very quickly?

Post by white exec »

GiveMeABreak wrote:
30 Aug 2019, 15:22
Confirmed this is the correct VIN David. Citroen parts confirm the volumes and pressure for the corner spheres for your C5.

You have an Estate and the DW12ATED4 engine with H3+.
Your Front corner spheres should be 385cc and 52 Bar.
Your rear corner spheres should be 385cc Volume and 31 Bar.
It is the Front Regulator Accumulator sphere that is 385 cc and 62 Bar.
The Rear Regulator Accumulator sphere is 385cc and 45 Bar.
Done a quick check on David's VIN, and for the Estate rear sphere (Cit Parts, and Handbook) listing is 385/44bar.
31bar is shown for non-Hydractive models, and 25bar for the Saloon.

Will try to get some insight into those twin damper figures.
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Re: Why do new spheres go hard very quickly?

Post by GiveMeABreak »

Chris - David has H3+ - I think my figures are correct :wink: But - there is a discrepancy in the technical documentation and the parts info (not the first time). I'm sure I emailed PSa about this before - let me check....
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Re: Why do new spheres go hard very quickly?

Post by GiveMeABreak »

Yes - I did send off an email previously concerning the Citroen XM V6 24 V ES9J4, which is another example where the data conflicts with several sources and the parts information - I have sent it off again awaiting a response - but in David's case, the fronts are correct in either case.
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Re: Why do new spheres go hard very quickly?

Post by white exec »

Estate rear suspension specs usually do differ from those for saloon.
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Re: Why do new spheres go hard very quickly?

Post by detheridge »

And still the mystery deepens!
The front suspension on my C5 is now solid. On holiday in Anglesey last week I booked it into a Citroen garage for a full diagnostic, and they came up with the idea that all three front spheres plus the middle back sphere needed replacing. This to me is absurd, as I don't think all three of the front spheres can have gone so soon after being new six months ago - or can they?
When I got back home I rang aepdirect (aepdirect.com), who supplied the spheres and checked with them: Yes, they are the correct 52 bar ones for my C5. I asked the very helpful guy there what might be the problem, and he suggests that the suspension units on Mk.1 C5s are notable for seizing. In addition, or optionally, I've read here that the linkage to the antiroll bar can seize up and can be cured by judicious squirts of WD40 in the right place. Mind you, the flood water I had to wade through a couple of months ago on the Welsh Borders won't have helped!
So - does anyone have experience of freeing up stuck bits in the front suspension?
Best wishes,
David.
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Re: Why do new spheres go hard very quickly?

Post by GiveMeABreak »

The BHI (the hydraulic block) raises and lowers the suspension through various inlet and exhaust electrovalves. If you can raise and lower the car when commanded through all the settings and it does as it is told, then it won't be the height correctors. If it were, then the car would be riding too high or too low. And therefore if the height is raising and lowering, then fluid is going to and from the struts / spheres.

That would mean that the BHI is functioning properly.

So that leaves either air locks in the system - (did you bleed the system after replacing the spheres last time?) or possibly the spheres are shot - burst, punctured - but in either case without nitrogen. I have to ask - but is it possible you over filled the LDS tank - or didn't have it on the lowest setting when checking levels last time?

The saucer spheres on the C5s have a spike(s) on the inside of the sphere above the membrane. The sphere has a safety pre-form in its upper part. In the event of bursting through overpressure, the pre-form prevents projections of metal pieces.

to avoid the possibility of the sphere bursting. When that happens - there is no gas so no springing apart from the air in your tyres! So as you had it diagnosed at the dealer - Diagbox would of told them if the height correctors were functioning or not - so their advice on your spheres may be correct.
Sphere.PNG
ReferenceDesignation
17Suspension sphere (slimline type)
18Suspension damper
19Diaphragm
20Safety break point
I've had no experience of aftermarket spheres - and would only fit originals. The saucer spheres are not supposed to be re-gassed officially either - so if these spheres are reconditioned ones - I would avoid.
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Re: Why do new spheres go hard very quickly?

Post by detheridge »

Hi Marc = many thanks as always.
Yes, my C5 raises and lowers exactly as expected. I've followed your instructions regarding bleeding on the lowest setting and turning the steering wheel several times. This solved the heavy steering but the spheres are still hard. Does this mean that all three spheres were knackered from the start?

Their website states the following: 'AEP Direct are the Number one French specialist in the UK. Having a equivalent p/n application corresponding to the manufacturer, we stock I.F.H.S OEM standard spheres. Our service centre, (Citroen Services) fit IFHS and highly recommend you that for incomparable maximum life expectancy and comfort of a regulator sphere; you should buy I.F.H.S spheres.
We stock IFHS regulator spheres as they are the Original Equipment Manufacturer parts on Renault, Peugeot & Citroen and many other car manufacturers'.

Antone know more about this?

David.
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Re: Why do new spheres go hard very quickly?

Post by xantia_v6 »

IFHS spheres do not use the multilayer diaphragms that genuine Citroen spheres have, so the life on an IFHS sphere is around 3 years, wheras the genuine spheres seem to last about 15 years.

If the suspension rises and falls smoothly without binding, I would say that your issue is either hydraulic or spheres.

If you lean hard on a corner of the car and watch the tyre, do you see the bottom of the tyre deform without any movement of the suspension? If there is a little movement in the suspension before the tyre deforms, then the corner sphere is probably OK, and your problem is with the centre sphere or the control block.
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Re: Why do new spheres go hard very quickly?

Post by detheridge »

If there's a problem with the control block, does that mean replacement or could it simply be a stuck valve in there? Speaking from ignorance, may the block be leaving the centre sphere out so the ride is in sport mode all the time, if you see what I mean?
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Re: Why do new spheres go hard very quickly?

Post by GiveMeABreak »

The front and rear control stiffness regulators just regulate the soft or sport modes on H3 (MK I) by isolating or including the centre spheres. If the vehicle is raising and lowering through all heights, then hydraulic fluid is being supplied to and from the struts - so I can't see how it can be a supply problem. If it was an electrovalve issue, then the vehicle would either be in soft mode or sport mode permanently. But even in sport mode it would not make for 'solid' or hard suspension, it would just reduce the roll and pitch and firm up a little, but not to the point of making your teeth chatter.

I suppose this is down to what your interpretation of the spheres being 'Hard' is. I.E. if there is no springing on moving - it would be almost like driving on max. height setting - that sort of hard bouncing - is that what you are experiencing?
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Re: Why do new spheres go hard very quickly?

Post by white exec »

Could incorrect ride height result in 'solid' suspension on C5? It does on XM, even when set to just intermediate high.