How soft, or hard should suspension be ?

HDI · Unread post by **HDI** » 27 Aug 2011, 13:40

Have just replaced the front and rear suspension accumulator and rear anti-sink, or whatever it's called, sphere's. The main accumulator and all four wheel spheres were done last November.

I was expecting the ride to be properly soft and compliant after this as it was still a little harsh after just doing the wheel and main accumulator spheres. It isn't ! Apart from the brakes being a bit sharper and being a bit faster to rise and fall when the height control is operated, there is no difference to ride quality

It's fine over slow and even large undulations but sharp bumps like transverse ridges cause quite nasty jolts.

It feels soft and compliant when the back or front is pushed down and the electrovalves can be heard to operate.

Any comments, idea's please ?

DickieG · Unread post by **DickieG** » 27 Aug 2011, 15:16

As you can appreciate its rather difficult to descibe "how soft is soft". A good test would be to drive another normally sprung car along the same route to compare as its all too easy to be over critical of the ride of a Xantia once you become familiar with the car. As yours is Hydractive can you hear the Hydractive valves buzzing and clicking when a door is opened? If you want to test them when driving tune the radio to 171 or 174 LW and listen for a variation in the level of interferance whilst depressing the accelerator as that causes the valves to operate. If you're going to CXM it'll be a good opportunity to compare your car against others and get a Lexia session done.

Unread post by **Peter.N.** » 27 Aug 2011, 15:41

If its hydractive did you change the centre spheres, they are the ones responsible for the soft ride.

Peter

HDI · Unread post by **HDI** » 27 Aug 2011, 16:01

Thanks guys.

The hydractive valves can be heard.

All the spheres have now been replaced.
I did the 4 corner and main accumulator ones last November and all the others during the week.

The harsh jolting over sharp bumps and transverse ridges cannot be normal or typical for a hydractive Xantia surely ?
The only thing I didn't mention was that the suspension mode change switch does also work, the ride becomes firmer when depressed.

DickieG · Unread post by **DickieG** » 27 Aug 2011, 16:03

I think that's been done Peter as he mentions "Have just replaced the front and rear suspension accumulator".

DickieG · Unread post by **DickieG** » 27 Aug 2011, 16:12

HDI wrote:The harsh jolting over sharp bumps and transverse ridges cannot be normal or typical for a hydractive Xantia surely

If you are talking of speed humps such as the triangular rubber strips found in car parks then the suspension does get caught out over those and when going over hump bridges in particular they really do catch it out especially when landing.

HDI · Unread post by **HDI** » 27 Aug 2011, 16:22

Just normal road bumps but particularly those that are across the width of the road, like an expansion joint or ripples.
It's sharper bumps that are worst, large, undulating bumps are nice and wafty smooth !

Clogzz · Unread post by **Clogzz** » 27 Aug 2011, 16:28

I’ve had low LHM cause a rough ride, it’s something like very small bubbles returning to the pump instead of rising to the top.

HDI · Unread post by **HDI** » 27 Aug 2011, 16:35

That can be ruled out, I corrected the fluid level after the spheres were replaced.
Is ther any sort of bleeding procedure required when replacing any of the spheres ?

Clogzz · Unread post by **Clogzz** » 27 Aug 2011, 16:46

There’s a lot of benefit from Citaerobics, with pauses at low and highest level.

Unread post by **CitroJim** » 27 Aug 2011, 18:25

Have you carried out the normal hydractive functionality checks?

Breiefly, start up, allow pressure to stabilise on normal height setting. The system will be in soft mode so go and bounce each end to ghet a feeling for it when soft.

Now switch off, close all doors (tailgate included) and bounce again. The car will still be in soft mode. Keep bouncing each end until you hear the hydractrive electrovalves click off after 30s. The suspension will now switch hard and you should feel a very definite hardening of both ends.

Open a door to invoke soft mode again and both ends should go soft again.

If this test fails, or only one end behaves properly, then the hydractive system is not working properly and more investigation is needed...

Also, on resting idle (i.e. no bouncing of the suspension) what is the regulator tick interval?

Unread post by **xantia_v6** » 27 Aug 2011, 19:23

A couple of things not mentioned yet...

Incorrect ride height, especially front, can cause the suspension to be a bit harsh.

If everything else is OK, try pulling down the front strut gaiters and lubricate the struts with a bit of spray grease or LHM. This reduces the stiction for a while.

Unread post by **Peter.N.** » 27 Aug 2011, 20:21

Try bouncing each corner with the engine running, you should have 4" - 6" of movement possibly more on the back which will be softer.

Peter

HDI · Unread post by **HDI** » 27 Aug 2011, 20:21

Ride height looks ok, certainly not noticably out. Will have a look under the gaitors but that wouldn't explain the rear. Both ends certainly rise and fall smoothly when the height control is operated.

Jim, thanks for that, I'll go through that procedure and report back.

XantiaDaveEire · Unread post by **XantiaDaveEire** » 29 Aug 2011, 22:12

I have the same problem with mine although mine is non-hydractive,6 new spheres last month..the back takes a little longer than it should to come down from the high position,i think maybe the rear height corrector is a little sticky,the actual mechanisim itself that the dog bone is attached to is slow to release.

Possibly some light greasing might be the solution to both our problems

Dave