Xantia sphere change... bleed screw needed?

eskimoigloo · Post by **eskimoigloo** » 16 Dec 2005, 20:28

Hi,
Thinking of doing all of the 4 main spheres on my 2001 Xantia over the christmas break. There seems to be 1 method stated more than any for the rear spheres, but some say to loosen the bleed screw on the accumulator before removing, and some say not... which is correct? Also, can't seem to find front spheres mentioned anywhere, are they the same as the rear method? Crack off at full height, then remove once car lowered? Also i assume once the car is at full height the engine needs to remain off until the new spheres are fitted? Will it drop to the floor with engine off?

All advice appreciated.

Chris.

406 V6 · Post by **406 V6** » 16 Dec 2005, 20:43

The car only needs to be on its highest position for the rear spheres, since the ram/sphere rotates if not secured.
After the seal is "cracked", the lever is adjusted to the lowest setting then the bleed screw turned no more than half a turn.
Then you can remove the rear shperes and the front ones too, as the strut/sphere mount is tightened at the top and doesn't move.
Of course this method is for a standard HP system, having anti-sink it's another matter wich i don't master... but it has been covered several times, and recently too.

Cheers!

Post by **Peter.N.** » 16 Dec 2005, 21:50

I would concur with the above, except that I have not found it necessary to slacken the bleed screw, if you put it on the lowest suspension setting the pressure will drop to near enough zero.

Mandrake · Post by **Mandrake** » 16 Dec 2005, 22:13

Personally I have never found need to use the full pressure "cracking" method for the rear spheres, as long as you have a good tool and are careful. It should be pointed out too that many of the commonly used tools simply CANNOT budge a rear sphere when there is full pressure on them, as they are not strong enough.

So whether you use the full pressure cracking method is a matter of personal choice, what tools you have available, and whether the spheres have been overtightened by the previous person. If they were tightened correctly to just hand tight you wont have any problems getting them off.

Before unscrewing them the suspension needs to be FULLY depressurized, even a small amount of pressure left will give you a stream of oil.

On an anti-sink model do the following - regulator bleed screw *tightened*, set the manual height lever down, and run the engine for about 3 minutes. Yes it can take that long to fully depressurize for sphere removal, especially on a Hydractive 2 model.

Try wiggling the corner spheres on the the rear suspension - when there is no pressure the entire cylinder and sphere assembly should be free to wobble from side to side a bit. If its still solid, there is still some pressure.

Once the suspension is depressurized, turn off the engine and as a safety precaution, open the bleed screw half a turn. The reason for this is if the manual height override linkage should for some reason fail, it would be possible for some pressure from the accumulator to be transfered to the suspension, enough to potentially cause you harm. (Or at the very least cause a big mess) With the bleed screw opened this cannot happen as there is now no pressure anywhere in the system.

Now you can remove the spheres.

Regards,
Simon

andmcit · Post by **andmcit** » 16 Dec 2005, 22:15

eskimoigloo wrote:Also i assume once the car is at full height the engine needs to remain off until the new spheres are fitted? Will it drop to the floor with engine off?

Simon beat me to the draw here!

It HAS to be on the floor!! Maybe it's the way I'm reading this, but you're not talking about removing the front spheres whilst the car is raised onto it's high setting!?

You'll send an 'interesting' green cannonball flying through all in it's path or at the very least have an 'interesting' green shower!!

Andrew

Homer · Post by **Homer** » 16 Dec 2005, 22:24

Mandrake wrote:Personally I have never found need to use the full pressure "cracking" method for the rear spheres, as long as you have a good tool and are careful. It should be pointed out too that many of the commonly used tools simply CANNOT budge a rear sphere when there is full pressure on them, as they are not strong enough.

The reason for cracking the rears under pressure is that otherwise the whole strut can rotate and snap the pipe.

Mandrake · Post by **Mandrake** » 16 Dec 2005, 22:27

Homer wrote:
Mandrake wrote:Personally I have never found need to use the full pressure "cracking" method for the rear spheres, as long as you have a good tool and are careful. It should be pointed out too that many of the commonly used tools simply CANNOT budge a rear sphere when there is full pressure on them, as they are not strong enough.
The reason for cracking the rears under pressure is that otherwise the whole strut can rotate and snap the pipe.

Hi Homer,

Yes this is the reason usually given, however all the ones I have ever worked on have a guide bracket around the pipe entry flange which is plenty strong enough to prevent the cylinder from rotating during normal undoing.

Only in cases where they are extremely tight would the cracking method be needed IMHO, and once you have removed/refitted those spheres once and retightened them the correct amount by hand (and greased the faces slightly) you'll never need to "crack" them again in future.

Regards,
Simon

Post by **Peter.N.** » 16 Dec 2005, 22:37

In those 'impossible, cases, you will have to resort to a large hammer and chisel on the welded seam round the equator.

john alexander · Post by **john alexander** » 16 Dec 2005, 23:09

Hi mandrake. When I snapped the rear ram bursting the piston in the process the substancial bracket was as much use as an ashtray on a motorbike at holding the strut in place,just as well I took the pipe off first.Regards john.

eskimoigloo · Post by **eskimoigloo** » 16 Dec 2005, 23:13

Thanks guys, didn't find that bit about running engine whilst car on floor to depressurise anti sink valves! That could have been fun! I was intending to remove front spheres whilst it was on floor and not send a green rocket into orbit! Mine is Hydractive III, so I hope there aren't any other litle quirks I need to know, as everyone talks about I and II only on here usually. Basically as long as I can move the rear struts a bit once it's been sat on the floor for a while, and I crack open the beed screw half a turn on the accumulator under the bonnet, they should come off ok yes? Fronts are just nice & simple take off and put on job as I am reading it here...... a simple yes response if i have understood this correctly will surfice!

Thanks again for advice

andmcit · Post by **andmcit** » 16 Dec 2005, 23:19

eskimoigloo wrote: a simple yes response if i have understood this correctly will surfice!

There's no such thing as a simple job with a citroen mind, but you've got the general idea, yes!

I knew you weren't going to remove a sphere when under pressure - mind I've seen someone undoing the nipple on a sphere without realising it doesn't turn the whole sphere off!!

Nearly blew everyone's eardrums!!

Andrew

Mandrake · Post by **Mandrake** » 17 Dec 2005, 06:02

john alexander wrote:Hi mandrake. When I snapped the rear ram bursting the piston in the process the substancial bracket was as much use as an ashtray on a motorbike at holding the strut in place,just as well I took the pipe off first.Regards john.

All I can say to that is that sphere must have been DAMN tight and you must have attacked it with a great deal of gusto

On really stubbon spheres I find its usually better to work away at them and use shocks rather than using brute force. Usually a combination of one person holding strain on the strap wrench while a second person patiently taps the side of the sphere with a block hammer will free it after a while without excessive force.

Another trick is to spray a little bit of rust penetrant such as LPS1 into the sphere/cylinder junction a few minutes before trying to undo it to help the rust bond break when you try to remove it. (The rust bond is often the main thing stopping it coming undone easily)

Took nearly 15 minutes of doing this to get the rear centre hydractive sphere undone the first time on my car as it had been EXTREMELY overtightened by someone, but I was able to get it off without any brute force or damage...

Regards,
Simon

Mandrake · Post by **Mandrake** » 17 Dec 2005, 06:10

eskimoigloo wrote:Thanks guys, didn't find that bit about running engine whilst car on floor to depressurise anti sink valves! That could have been fun! I was intending to remove front spheres whilst it was on floor and not send a green rocket into orbit! Mine is Hydractive III, so I hope there aren't any other litle quirks I need to know, as everyone talks about I and II only on here usually.

I hate to break it to you, but there is no such thing as Hydractive III on a Xantia, Hydractive 3 is something some models of C5 have, and Hydractive 1 only existed on the XM.

The Xantia only came with three varients - ordinary Hydropneumatic, (much like the BX and all earlier models except with the addition of anti-sink valves) Hydractive 2, and the Activa system technically called SC-CAR which is Hydractive 2 plus the addition of the rollbar rams and related systems.

Yours isn't an Activa is it ? Because there are additional steps to follow to depressurize before replacing the Activa spheres.

Basically as long as I can move the rear struts a bit once it's been sat on the floor for a while, and I crack open the beed screw half a turn on the accumulator under the bonnet, they should come off ok yes? Fronts are just nice & simple take off and put on job as I am reading it here...... a simple yes response if i have understood this correctly will surfice!

In principle sphere changing is simple, in practice it depends on whether the person before you did a decent job and didn't overtighten the spheres. Overtightening seems to be the number one mistake a lot of people who dont know better make.

Citroen recommends they are only tightened as tight as you can do them with two bare hands, but a lot of people ignore this advice and tighten them with the untightening tool....if it leaks when they are hand tight something is wrong with the seal - remove it again and find what the problem is rather than tightening it more or trying to use some kind of gasket sealant. (Another big no no)

The only other thing to watch is to make sure you oil the seal slightly and put it into the recess in the cylinder, never slip it over the neck of the sphere or it will get pinched. A little wipe of grease on the flat faces where the sphere and cylinder come together will usually prevent it forming a rust bond later and together with not overtightening makes it MUCH easier to remove again a few years down the road...

Regards,
Simon

eskimoigloo · Post by **eskimoigloo** » 17 Dec 2005, 08:43

The guy that fitted them before me was the guy in the Citroen factory... they are still original ones... hence need for change after 4 years! It's not Activa no, it must be Hydractive II then, a mate said it was III (never mind). What other spheres are there on mine then? Just the accumulator/s? Is there one front & rear? Or are there just the 5 spheres? Don't think the accumulators have gone though as it only ticks about 3 times getting from flat on the floor to wheel change mode!

Cheers, Chris.

Richard Gallagher · Post by **Richard Gallagher** » 17 Dec 2005, 09:55

On Hydractive Xantias you will have a sphere on each strut as per usual, then another 'Hydractive' one on each axle (front one is behind the radiator, rear in the centre just behind the fuel tank with large metal pipe into it). You will also have the accumulator sphere attached to the gearbox and on models built from around 95 onwards another antisink sphere located near the rear Hydractive sphere (Antisink sphere has a small pipe into it).

Personally I would change the Hydractive spheres as well as the strut sphere's as they do make a substantial difference to the ride comfort.

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Xantia sphere change... bleed screw needed?

Xantia sphere change... bleed screw needed?

Re: Xantia sphere change... bleed screw needed?