How long should spheres last

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Pcheaven
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How long should spheres last

Post by Pcheaven »

Sorry.

Newbie question. I tried to find the answer here and couldn’t

I think mine are the original ones, and the car doesn’t handle speed bumps well.
The initial hit to the speed hump is fine. It’s when the front wheels come off the bump the suspension hasn’t recovered and the bumper grounds out.

Suspecting ages spheres / accumulator.
BX Meteor. Sub 20000 miles. Very Original.

ToDo list.

1. ̶G̶e̶t̶ ̶c̶a̶m̶ ̶b̶e̶t̶ ̶e̶t̶c̶ ̶r̶e̶p̶l̶a̶c̶e̶d̶ ̶e̶t̶c̶
Have a GnT
2. G̶e̶t̶ ̶t̶h̶e̶ ̶r̶a̶d̶i̶o̶ ̶t̶o̶ ̶w̶o̶r̶k̶.̶ ̶
Have a GnT
3. Adjust the clutch
Have a GnT
4. Clean LHM tank then a complete flush
Have a GnT
5. Wash, clay bar then ceramic coat paintwork.
Have a GnT
6. Replace rear spheres
Have a GnT
7. Replace bottom hose

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jamescarruthers
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Re: How long should spheres last

Post by jamescarruthers »

I’d be looking for a pressure check and regas after approx 5 years. My favourite for this is Pleiades in Sawtry as they don’t mess about— they just whip them off, test and regas nice and quick. If you are making a day trip, you should make sure they have the correct ones for your car in stock just in case yours can’t be regassed.

They aren’t so close to you but well worth the trip. In my book for a BX, they are THE Citroen hydraulic specialists.

Surprised the bumper is grounding out.

With the engine on, how often do you hear the loading and unloading click of the accumulator sphere coming in/out of the circuit?
1987 Volvo 480 ES
2006 Citroen C6 Exclusive 3.0 petrol/LPG

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A966 XRL -- BX 16 TRS
H767 BEG -- BX 14 TGE
B316 AMP -- BX 14 E

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white exec
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Re: How long should spheres last

Post by white exec »

Not sure how much mechanical work you can/want to do yourself, but you can do your own sphere checking and re-gassing with a Tecnosir C720 tool, which costs c.€150. See Tecnosir's website for a video, and details. Tecnosir also supply the 9mm Valprex re-gassing valves for the spheres.
Chris

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jamescarruthers
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Re: How long should spheres last

Post by jamescarruthers »

Do you have to completely depressurise the hydraulic side to get an accurate reading on the gas side of the spheres to do this Chris or do the spheres still have to come off for checking/recharging? I’ve always wondered about this as I can’t see how you can get the Nitrogen correct otherwise.
1987 Volvo 480 ES
2006 Citroen C6 Exclusive 3.0 petrol/LPG

Previous BX's:
A966 XRL -- BX 16 TRS
H767 BEG -- BX 14 TGE
B316 AMP -- BX 14 E

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white exec
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Re: How long should spheres last

Post by white exec »

You're right, James - there needs to be no hydraulic pressure into the sphere when checking/setting the pressure.
Easy enough to depressurise on the car on the BX, because the system is so simple. A good few firm applications of the brakes will also void any remaining pressure at the back.

Hydractive should be the same, but likely with anti-sink as well, bigger chance of pressure lurking. Having got caught out once on XM, and ended up getting quite the wrong gas pressure, I now tend to check/top up with the sphere removed from the car. Only a once-every-three-years+ job, so not too onerous.

The Tecnosir video does show them being done on the car, and for non-HA, no reason why not.
Chris

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jamescarruthers
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Re: How long should spheres last

Post by jamescarruthers »

That is interesting. I will add it to my BX dream list, along with a BX!
1987 Volvo 480 ES
2006 Citroen C6 Exclusive 3.0 petrol/LPG

Previous BX's:
A966 XRL -- BX 16 TRS
H767 BEG -- BX 14 TGE
B316 AMP -- BX 14 E

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Dave_16v
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Re: How long should spheres last

Post by Dave_16v »

I am not sure if the spheres will cause the problem encountered but if they are the originals or even very old, I would just buy new ones, it won't cost much more if anything. My understanding of refilling spheres is it needs to be done far more regularly than you would replace them in order to keep them healthy. Once they get to the point of needing a refil, the internals may be damaged and unable to hold pressure for long.
I envisage if the car was taken for checking, a conversation would be had along those lines because once they get so far, the chance of failing increases. If I was using my BX regularly, then refilling would possibly be something I would do to keep them in top condition, it seems to be a really good idea so the tool Chris suggested above would almost be a must.

I have seen it said that if left with the pressure released, the membrane doesn't necessarily deteriorate as they would generally. Mine seem OK after all the years so that would seem to support that theory.
Last edited by Dave_16v on Sun Apr 04, 2021 3:10 pm, edited 1 time in total.
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white exec
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Re: How long should spheres last

Post by white exec »

Sphere cross-section.jpg
.
What finishes spheres off (apart from extreme old age) is driving the car with very low gas pressure. This forces the membrane upwards, against the internal pressed-steel dome that holds the diaphragm in place. Some of the aftermarket spheres have less-than-smooth edges on the perforations in this plate, and this can damage the diaphragm. (Genuine Citroen spheres have rolled-back edges to these perforations, and the problem is avoided.)

In normal use, at correct pressures, the diaphragm will never touch this metal dome, and neither will it be asked to flex upwards by that amount. It's usually reckoned that if a sphere's gas pressure has dropped much below 15 bar, it ought to be ditched, rather than re-gassed.

Driving on flat or nearly flat spheres is what countless BX and Xantia owners did out here in Spain (and probably elsewhere too), too mean or too ignorant of the need to maintain this type of suspension. The result was a bumpy ride ("not the ride it used to be...") and - in countless Xantia (and XM) cases - sheared front strut tops and speared bonnets.

Not sure about that recommendation of leaving the pressure (presumably the gas?) released. OK for spheres stored off the car, but not a good idea on the car, if it were to be started and raised. Maybe I misunderstood.

If good quality spheres are used, and kept at proper pressures, their life can be extremely long. Being able to check the gas pressure (as well as top it up) is what makes the re-gas kit so attractive - especially now that the cost of the tool has reduced. For anyone running more than one fluid Citroen, it's a really good investment.
Last edited by white exec on Sun Apr 04, 2021 9:26 pm, edited 2 times in total.
Chris

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Dave_16v
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Re: How long should spheres last

Post by Dave_16v »

white exec wrote:
Sun Apr 04, 2021 3:09 pm
Not sure about that recommendation of leaving the pressure (presumably the gas?) released. OK for spheres stored off the car, but not a good idea on the car, if it were to be started and raised. Maybe I misunderstood.
I think you have misunderstood, I simply mean parked up and bottomed out as they do in any case over a few days or hours depending on the system. That presumably takes pressure off internally and they are effectively, similar to being sat on a shelf where they don't deteriorate as they could left full of lhm and in use. Hence mine seem to have lasted but they weren't worn out when I more or less stopped driving it regularly it at the time.
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white exec
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Re: How long should spheres last

Post by white exec »

Got it. That should prolong overall life, as it reduces the gas pressure to the "book" figure, the same (as you say) as sitting on a shelf. On the other hand, I'm guessing that a 'balancing' hydraulic pressure - supporting the weight of the car - would provide an equal force on the wet side of the membrane, and so resist leakage of gas. Hmm. Difficult one.

Advice has always been to avoid buying new spheres which have sat on the shelf for years.
Genuine Citroen spheres are factory dated (some others are too).
I wouldn't be happy buying any sphere more than around 18 months old, and no bad thing to check the gas pressure (if you can) even on 'new' ones, as there is slow pressure loss even on the shelf. Citroen's own 3-layer (multicouche) membranes - usually for the hot engine-bay locations - are resistant to this, and are patented and exclusive to them.
_____________

There's a really good and well-illustrated post here (on FCF) all about sphere failures:
https://frenchcarforum.co.uk/forum/view ... 13#p649013
Chris

Pcheaven
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Re: How long should spheres last

Post by Pcheaven »

So I guess the consensus is mine being original spheres, whilst still soft should be replaced or recharged.

I think my tick is around 50 seconds.
BX Meteor. Sub 20000 miles. Very Original.

ToDo list.

1. ̶G̶e̶t̶ ̶c̶a̶m̶ ̶b̶e̶t̶ ̶e̶t̶c̶ ̶r̶e̶p̶l̶a̶c̶e̶d̶ ̶e̶t̶c̶
Have a GnT
2. G̶e̶t̶ ̶t̶h̶e̶ ̶r̶a̶d̶i̶o̶ ̶t̶o̶ ̶w̶o̶r̶k̶.̶ ̶
Have a GnT
3. Adjust the clutch
Have a GnT
4. Clean LHM tank then a complete flush
Have a GnT
5. Wash, clay bar then ceramic coat paintwork.
Have a GnT
6. Replace rear spheres
Have a GnT
7. Replace bottom hose

User avatar
white exec
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Joined: Sat Sep 12, 2020 4:04 pm
Location: Sayalonga, Malaga
My Cars: 1992 BX19D Millesime
- LHD, NA, AC, RP_5800
1996 XM 2.5TD Exclusive
x 61

Re: How long should spheres last

Post by white exec »

If they really are the originals, then they've done well, assuming there's any gas left in them at all!
By the sound of it, there might not be - lumpy and crashy ride, coming off humps.

I should replace all five.
Go for IHFS (from AEP Glasgow), or for genuine Citroen ones if you can afford them.
I can post the correct Cit pt nos if needed.
Chris

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Re: How long should spheres last

Post by rutter123 »

If the front bumper is grounding out I suspect your problem may be the front struts sticking, if your spheres were flat (lost their gas) you would not get any suspension travel, it would just bounce, if a sphere breaks internally that will cause that corner to bottom out?
It may be worth checking that your height lever and correctors are operating correctly and don't rule out the hyd pump as a knackered one will struggle to keep up.
I also recommend Pleaides Martin is a wealth of Citroen hydro
Your very lucky if you don't have any leaks and all your major suspension components are working as they should after 30 odd years, otherwise it can become quite costly.
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white exec
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Re: How long should spheres last

Post by white exec »

Forgot - 1 click every 50secs (while driving) is quite acceptable. A click every few seconds usually means a pooped Acc sphere.

As said, check the vehicle height when set on Normal.

Also do a bounce test:
- engine running, car stationary
- press down on the front, and it should go down fairly easily by about 10+ cm, then come back up
- do same at the back (or sit on the boot ledge), should go down 15cm or so, and return
You should feel real softness.

If the height lever is set to Highest, and you do the bounce test, you will feel what it's like to have spheres without gas - solid.
Chris

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Tim Leech
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Re: How long should spheres last

Post by Tim Leech »

The fronts on the GT are at least 14 years old and are as soft as always, yet the rears which were fitted at the same time lasted 10 years before needing to be changed, its down to use etc

I ALWAYS depressurise the hydraulics when I park up unless im just going to the shop etc
Lots of Motors, mostly semi broken....