Hard Rear

Mark8 · Post by **Mark8** » 03 Dec 2004, 03:51

Hi
Newbie here,who has just purchased a 1998 xantia 1.9td.
I'm here to pick the brains of you wise people,my xantia's rear suspension is solid in all height positions,so i asked my mechanic to change the rear suspension sphere's,which he did but unfortunately it is no better......he thinks it could be the anti-sink sphere that is causing the problem.
My question is if this could be a possible cause....i take it the anti-sink is just a one way valve of some sort,apart from being solid at the rear it does everything it's supposed to....ie.rises,lowers,settles at normal and stays up if left.
Regards
Mark

DoubleChevron · Post by **DoubleChevron** » 03 Dec 2004, 10:03

You Xantia should NOT be hard with new rear sphere's under it. By hard I mean, as hard as the car is with it on 'high'. If it still rides reasonably but isn't as good as you know it should be (ie: as hard as the car would be if in hard mode) then yes your center sphere is the problem.
The center sphere is what gets cut out of the circuit when the car is in hard mode. If it's flat that is the equivilant of your car being permanantly in 'hard'. When I replaced the rear H/A sphere on my car the difference in ride quality was immediate and dramatic. I can't say the reason for this is only the H/A sphere as I also had the rear suspension sphere's regassed at the same time.
good luck
Shane L.

alan s · Post by **alan s** » 03 Dec 2004, 13:09

Sounds like mine was but possibly not as bad.
http://www.andyspares.com/discussionfor ... IC_ID=9740
Alan S

windy · Post by **windy** » 03 Dec 2004, 17:38

Since the question has come up, should the rear of a non-HydraActive Xantia be as soft as the front? When given the bounce test by leaning on the wings, the front of mine is much softer/bouncier than the rear. On my past BXs and GS, I seem to remember front and rear being equally bouncy.

dnsey · Post by **dnsey** » 03 Dec 2004, 20:09

I've replaced all four spheres on my Xantia, and the rear is still stiffer than the front, so I guess that's how it should be.

Mark8 · Post by **Mark8** » 03 Dec 2004, 20:44

So,from your your replys...i get the feeling the anti-sink sphere can have an effect on the suspension other than just keeping it up when left.
I'll get it changed and see what happens.
Cheers for the help guys [:)]

alan s · Post by **alan s** » 04 Dec 2004, 05:47

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by dnsey</i>

I've replaced all four spheres on my Xantia, and the rear is still stiffer than the front, so I guess that's how it should be.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Quite the opposite; the rear is as soft as hot butter.
Change the anti sink but be careful as it has a line screwed into the back of it that takes around a 9mm spanner and is not just a simple screw out like the others.
Once the line is out, then it just screws out like the rest.
Mine is a bit hard at the front but I have been told two stories; one is that being a hydractive that's rthe way it is whilst other reckon it's due to having non hydractive spheres fitted.
Almost ever time a Xantia stiffens up though, the anti sink seems to be in there as part of the problem.
Alan S
Alan S

alexx · Post by **alexx** » 05 Dec 2004, 04:51

Mark, anti-sink sphere is only a pressure accumulator for rear brake circuit. Anti-sink system will work without it as well. Also, it has only a marginal influence to the ride. Older Xantias (up to '94) didn't have it, and they didn't have solid rear suspension either.
Rear should be about twice as soft as the front - it should dive two times more under the same weight. But on '98 Xantia this difference is smaller, because rear bump stops are quite close to the rear suspension arms.
If your car has hydractive (VSX and higher level of trim), check rear H/A sphere first - the one mounted on the rear stiffness regulator, and electrical connection to the regulator also.