Xantia hydractive suspension

ActivaV6uk · Post by **ActivaV6uk** » 18 Apr 2005, 16:21

Ok I’ve gone through the TD project cars history and it has had all the spheres changed except the front pair.
Now the car is an Activa and its sphere combination is very high pressure so does give a slightly firmer ride on some roads however the rear feels like tis on flat spheres, and the plastic clip also broke shortly after we started using it.
So what could be causing the hard ride, I will be putting different spheres on it soon any way but I don’t think that’s the answer. Citroen don’t know I’ve got a receipt for £300 for a full suspension check!
Do the struts cause this sort of problem or could it be stiff arms?
Andy

alan s · Post by **alan s** » 18 Apr 2005, 16:37

Is it an Activa or a hydractive 2?
I have a Hydractive 2 and mine was as hard as a rock when I got it. I found the spheres were blown all over the show. If however the anti sink or hydractive at the rear blows, it will make it ride like a dray.
In case you haven't done one of these previously it's a work of art ridding the system of pressure as it's done with the engine running and the suspension set at low and the door open and the anti sink is unusual in that it has a peipe with fitting screwed into the back of it.
Shane does a good pictorial description on his site
http://www.aussiefrogs.com/shane/
Alan S

ActivaV6uk · Post by **ActivaV6uk** » 18 Apr 2005, 17:40

Activa is a HA 2 + sc.car (people keep kidding them selves that Activa is so much different when all it is is an extra system) and they work with out any information from each other. So HA info is applicable to this as the Activa system is working properly.
One of the spheres I have in a box that hasn’t been fitted to the car is the accumulator, so I will start with that first. Thanks Alan
When it comes to fixing Activa’s there is a really easy way to work out ware the problem is. firstly if it goes round corners flat with no noticeable correcting action (read bounce) then the Activa system is fine and you need to start looking at the HA system and the HA system has lots of people who have it.

the other thing to remember is about the cars ride quality I’m about to try and experiment that we sort of already know what the answerer will be, the Activa spheres are incredibly firm (for a Citroen) I'm going to be fitting 2.1 TD standard HA spheres to the car too see what happens, I expect that the car will act just like the 2.1 VSX until you reach a corner, what I’m really interested in is how the difference form smooth strait to smooth flat cornering will be I have a fear this may be the down fall of this idea, if that is the case then I will be trying very soft HA centre spheres and see if the car is better like that, all the HA cars cut the centre spheres out when cornering so it may be that’s the answerer.
Andy

bernie · Post by **bernie** » 18 Apr 2005, 18:21

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by alans

If however the anti sink or hydractive at the rear blows, it will make it ride like a dray.
Alan S
<hr height="1" noshade id="quote"></blockquote id="quote">
Alan would you please describe fully these symtoms?
Thanks
Bernie

alan s · Post by **alan s** » 18 Apr 2005, 18:39

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by bernie

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by alans

If however the anti sink or hydractive at the rear blows, it will make it ride like a dray.
Alan S
<hr height="1" noshade id="quote"></blockquote id="quote">
Alan would you please describe fully these symtoms?
Thanks
Bernie
<hr height="1" noshade id="quote"></blockquote id="quote">
Very simple; the rear end is rock hard and when you push down on the back it will not move just as though the rear arms are seized.
There is also no difference between sport and comfort mode.
When the car is started, it rises instantaneously regardless of how long it has been left sitting mainly because (I suspect) the sphere is packed solid with LHM.
When removed, it will definitely give you a bath in lime fizzy.
Alan S[}:)]

bernie · Post by **bernie** » 18 Apr 2005, 20:54

Thanks Alan
Mine seems to be the exact opposite.
Very little springing and bottoms out too easy
Last couple of days I fitted a pair of spheres from the front of my BX estate 55 bar 1.4 holes to the rear of my Xantia.
A lovely floaty ride was produced but under damped.

Mandrake · Post by **Mandrake** » 30 Apr 2005, 06:53

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by bernie

Thanks Alan
Mine seems to be the exact opposite.
Very little springing and bottoms out too easy
Last couple of days I fitted a pair of spheres from the front of my BX estate 55 bar 1.4 holes to the rear of my Xantia.
A lovely floaty ride was produced but under damped.
<hr height="1" noshade id="quote"></blockquote id="quote">
Holy cow batman!
Don't do that [:D]
The front spheres from any model won't be suitable for the back because the pressure will be too high, and the damper hole will be too large.
The high pressure will make the springing extremely soft beyond the point of diminising returns, (loss of handling with no real gain in ride from the optimal) and it may even damage the sphere, as the diaphram may bottom in the sphere during the extension stroke with no load in the boot.
The 1.4mm damper hole will be much too large for the back, which normally has about 1mm.
Just recently we changed the rear Spheres on my Dad's Xantia (2.0i) and the wrong spheres were supplied, they were 40 bars instead of 30, and the back was far too soft.
It would duck under acceleration, and rise under breaking, the height corrector was forever correcting up and down during dynamic changes in driving. At high speeds the back felt lively and underdamped.
When they were replaced with the correct 30 bar spheres (after quite an argument with the local Citroen suppliers who were adamant that 40 bars was correct, but later admited we were right and it should be 30) it was like a different car.
(See: http://www.gsfcarparts.com/downloads/sphere_table.pdf)
The ride didnt seem any worse, but the handling and rebound control was spot on. You can push down on the back and release it, and it rises moderately fast with no overshoot whatsoever.
I can't even begin to imagine how bouncy and uncontrolled your 55 bar 1.4mm spheres would have been [:)]
On the other hand, those same spheres on the Front may have been a slight improvement - the standard 2.0i front spheres are 55 bars and 1.5mm, if you put your 55 bar 1.4mm spheres on the front the springing would be the same, but the damping would be noticably firmer, and may improve the handling slightly...
Regards,
Simon

Richard Gallagher · Post by **Richard Gallagher** » 30 Apr 2005, 12:32

Andy, a good way to check if the Hydractive sphere is working and or flat is to push down on the suspension with out the engine running and note the 'softness'.
Then open a door/boot lid and listen for the slight buzzing as the 'Anti-jolt' system is activated. Push down on the suspension again and compare this softness to when pushing down with out the door open.
The suspension should be noticeably softer when a door is open.