Will Buy A Xm

Sphere recharging links:
http://www.mars.dti.ne.jp/~ynar/bxorg_archives/t03/t03e.html
http://www.tecnosir.com/english/index_eng.html

Helps to explain a bit more!

Andrew

Thanks for your answers!
I have a sphere from a friend's Xantia, about 10 years old, I cuted it in half in a lathe, and discovered a very good (looks at least) rubber inside, how long does a diaphragm rests?

Cheers from a warm Brazil

Caique

Apologies for a minor topic swerve, but could the gassing process described above be applied to an S3 C5? I'm kind of excited that I could improve the ride quality still further - softer is better in my book!

Hi ThwartedEfforts,

Unfortunately no, you can't add pressure to your C5. All C5s (from S1 to S3) & C6s have sealed spheres, they last around 5 years (during which time the suspension slowly gets a bit harder and harder) and then you throw them away and buy new replacements.

This is also the way with normal/older citroens, which you can regass, People live with them for say 5 years without doing anything to the spheres. They think the suspension is fine as they have not noticed the gradual loss in psi to their spheres. Once regassed its amasing the difference - my XM is very very soft indeed, but still corners very nicely thanks to the sports setting and the fact its mainly the soft spheres that we have added pressure to.

However, on older citroens, such as your Xm, xantias, bxs etc etc, you can regass the spheres. So in theory if the spheres are kept on top of they will last the life of the car - providing they have been regassed at the right time.

So ... a Citroen specialist will be able to regass your spheres on your XM. You could ask them to add a little more PSI to them, which is what we did. You really need to know what your doing though, so some specialists might not want to do this. Its not unsafe or anything, purely gives a better ride.

As i said above, my dad used to be a citroen specialist, so we still have all the gear to do them, which comes in handy for our two hydraulic citroens.

The diaphragm in a sphere is ok unless the pressure has been too low.

Low pressure can cause the diaphragm to contact the inside of the sphere damaging it. THen it can no longer be regassed, so there must be a minimum (i forget the actual figures) ammount of gas left in the sphere for it to be rechargeable.

We have a display kit in the garage somewhere, which imcludes cut open spheres and info on how they work and also diaphragms which have been damaged be too little pressure.

My local Citroen dealer has a long history with the manufacturer and sold my neighbours their CXs and XMs (yes, it's all their fault!) long before I even had a driving licence

I'm hoping the service manager there who is an older chap and very helpful will be able to help me shove some extra pressure in the spheres. Is there a guide amount, such as you might find when inflating tyres? Presumably they also vary front to rear.

EDIT: Having checked with the dealer, they have spheres still on the shelf but no longer have the equipment to alter their pressures. Looks like I'll get in touch with one of the specialists recommended to me in another thread.

This post has been edited by ThwartedEfforts on October 28, 2008 01:06 pm

Ah interesting, Citroen dont regas anymore!

Hmm, i would think there is a guide on here as to sphere pressures. Each one is different - you have 7 spheres on the XM. I think the front wheel spheres are about 35, the front soft about 60.

Ill check and let you know what mine are at now!

Its a fairly inexpensive thing to have them regassed, all are quite easily accessible apart from the rear soft sphere which is behind the exhaust heat shield at the back of the car.

There are a fair few citroen specialists which you can use, the ones already mentioned are good. We have used Pleiades, they are good.

Will report back with the results of whatever I end up doing

Unless I'm missing something fundamental about the engineering involved, I'd have thought it would be a good business to sell modified later spheres (ie from C5s, C6s) to give a softer ride. I understand they're sealed units, but someone must fill them with gas!

This post has been edited by ThwartedEfforts on October 28, 2008 08:02 pm

There may be some 'back street' way of doing it. However the problem is the older spheres have a nipple fixing on the opposite end to the fixing which it screws onto the car. Newer spheres from the C5/6 dont have that, so im not sure there is even a dodgy way

IF you Order spheres from GSF VIA their Ebay, their ID "gsfparts" I think, their spheres work out at about 24 quid EACH delivered... thats 38.00 for the pair and about 6 quid delivery!!

I ordered a pair last week from them for a customers 2.oi Xantia rears, and recived a pair that were 3 weeks old... The date was that new!!

http://cgi.ebay.co.uk/CITROEN-XANTIA-BX-CX...id=p3286.c0.m14

DO NOT BUY THEM FROM THEIR WEB SITE THEY COST SO MUCH MORE..

So in theroy the days of regassing is not worth it


Rgds
Paul

It is if you want to add pressure!

Although most citroen specialists charge between £15-£20 each for regassing, so not far off your new price.

Wow, cheap. Thanks for the heads up.

Am still waiting to hear back from my Citroen dealer but I doubt he'll be able to beat that kind of price, especially as he was quoting around £60-something a sphere last week. Maybe that was fitted - all will be confirmed soon I hope.

Question: are the eBay ones above The Real McCoy? Are there such things as 'non-genuine' spheres? I'm just worried that these are somehow of an inferior quality or workmanship, or there'll be slightly the wrong size or what have you. Is my ignorance showing

There are non genuine spheres yes, and id not recommend them.

We have had a few problems with customers cars, who brought their own spheres to be fitted and they went bang as soon as the car pressurised. Others have lasted a while and then failed. So my dad would only ever supply and fit genuine citroen spheres.

So be careful!

Hi

I want to understand more about the hidraulic "clicking", the pump works all the time and the regulator clicks to send more pressure or the pump is released until the click? My XM was doing every 14 seconds, now its around 8, is that wearing so much the pump? what is exact doing when it clicks, a valve?
Replancing the accumulator sphere will solve this?
sorry asking so many questions in a role.

cheers and thanks

Caique

Hi Caique

The Citroen hydraulic system (steering, brakes, suspension) is designed to be supplied by a pressure that is regulated continuously from 145 +/-5 bars to 170+/-5 bars. This is the role of the pressure regulator. It does so by allowing the LHM pressed by the pump to pass and compress the system, or to return to the LHM tank (unpressurised). The click u can hear is when the regulator "cuts in", i.e. diverts the pump to pressureise the system (the accumulator sphere, to be precise). So when the regulator feels the accumulator to drop below the minimum, it cus in and raises it to the high. During this (that should last about 1-2 secs) the pump is heard "rattling". Then the accumulator, inflated to 170 bar, is giving the pressure to the system till it drops again to 140bar and so on...This process takes 8 seconds on ur XM, i.e. ur XM consumes the pressure differential between high-low in 8 secs.

This is low but not dangerous for ur pump. It is bad for the pump when there's no click anymore (i.e. accumulator sphere is emtpy of gas and/or there's such a huge leak somewhere that the pressure cannot even reach the high level -170bar-), then the pump is supplying the system direct and receives the pressure shocks backwards from the system. A DIRAVI XM like urs and mine is very good if it achieves intervals of about 30-40secs. I guess u know that the DIRAVIs also have 1 additional accumulator dedicated to the brake circuit -this seats next to the radiator's bottom, and it is the same type of sphere as the main accumulator (62bar, no damper)-. This sphere is isolated with a 1-way valve from the rest of the circuit. So, on our DIRAVI cars, the main accumulator supplies: suspension and steering, and brakes but only if those are lower in pressure than the main accumulator.

One common problem is that the regulator, which uses 2 springs to "feel" the low and the high pressures, gets worn (precisely, it is these 2 springs that get tired) and the result is that the regulation interval is dropping from the optimal 145-170 bar. In my 222.000km 3lt I found it to be giving 137-157 bar.

While in any other Cit this will cause gradually slower rising, stiffer/intermittent steering assistance, etc, Hydractive cars are hit even more because they need about 150 bar minimum to open up the hydractive pistons (1 per axis) that give the "soft" setting. My car was hard without other reason and as soon as I re-tuned the regulator to 145-170 bar it became soft instantly -this was the first time I saw it soft-.

The way to re-tune the regulator is to add specific washers between the springs in it. For each 1mm added the pressure rises 1 bar. I had to buy 3 other old regulators to find the amount of washers to fix mine. But of course one cold use any washer.

How to measure the regulator's pressure output? I was lucky to have the specific Citroen kit from my garage.

cheers
George

This post has been edited by jorgy9 on October 29, 2008 04:44 am