Old LHM.. better ride?

hubrad · Post by **hubrad** » 04 Aug 2007, 23:49

Hi chaps! I've been really enjoying and benefitting from reading in here; time for my first question.
I've had this Xantia 1.9 TD Estate about 2 months now, and have already decided the centre rear sphere probably needs replacing, as the rear end is really slow to rise even after many 'robics sessions.
Anyway, I decided first of all to change the LHM as the old stuff was a lovely (if you're into mucky caramel rather than LHM) mucky caramel colour rather than any shade of green. 73k seems an ideal point to do this in any case.
Suddenly the ride suggests that I probably need to replace all the corner spheres too. It wasn't brilliant before, but is noticeably worse for the new fluid. Most folks seem to say that new fluid improves the ride. Has the change merely brought the poverous state of my spheres to the fore?
Any pearls of wisdom?
Thanks in anticipation, HUGH

Mandrake · Post by **Mandrake** » 05 Aug 2007, 01:58

I think your experience rides against the tide of everyone else.... I've never heard of new LHM making the ride worse before.

Most likely there is an unrelated problem, or you're just noticing it more now that you're looking...

Regards,
Simon

jeremy · Post by **jeremy** » 05 Aug 2007, 07:32

Don't worry - give it a few days and the car will feel just like it used to as the molecules in the LHM get mashed up a bit or something.

I've had this a few times on my BX - personally I rather liked the soft bouncy ride the new LHM have me even if the thing did roll a bit.

Enjoy it while it lasts.

Post by **Peter.N.** » 05 Aug 2007, 15:45

Its the centre spheres that give you the soft ride and are often overlooked, so I would try changing those first.

hubrad · Post by **hubrad** » 05 Aug 2007, 17:12

jeremy wrote:Don't worry - give it a few days and the car will feel just like it used to as the molecules in the LHM get mashed up a bit or something.

I've had this a few times on my BX - personally I rather liked the soft bouncy ride the new LHM have me even if the thing did roll a bit.

Enjoy it while it lasts.

I forgot to be specific.. by 'worse' I mean solid as a rock kind of bouncy!

It wasn't brilliant when I first got it, esp. compared to the last couple of BX, but living at the end of a rough track it's crawling pace only just now!
Rear centre sphere is my first intended port of call, followed by axle pairs, then accumulator to make the full set!

Post by **xantia_v6** » 05 Aug 2007, 22:00

I have the impression that your car is not Hydroactive 2, in which case the centre sphere is the so-called anti-sink sphere, and has no effect on ride quality, so don't expect any improvement on changing it.

On a non-HA Xantia, flat outer spheres or severe hieght error seem to be the only causes of a hard bouncy ride.

AndersDK · Post by **AndersDK** » 05 Aug 2007, 22:21

xantia_v6 wrote:I have the impression that your car is not Hydroactive 2, in which case the centre sphere is the so-called anti-sink sphere, and has no effect on ride quality, so don't expect any improvement on changing it.

On a non-HA Xantia, flat outer spheres or severe hieght error seem to be the only causes of a hard bouncy ride.

if it is a hydractive model - then you will have 4 spheres in total - in the engine compartment alone :
2 wheel spheres - 1 system main accumulator - 1 front axle center sphere.

- and of course 3 spheres under the rear.

deian · Post by **deian** » 05 Aug 2007, 22:36

Anders... Confused, i'm not questioning you knowledge, but you've thrown a spanner in my thinking here...

I know what HA2 is (cos i'm on my second one)... 8 spheres = 4 struts + 2 centre (front and back) + 1 anti sink + 1 accumulator

So you are saying the HA has a centre sphere too (as in not HA2), but the 3rd rear sphere is a what.... anti-sink, or centre?

So am I right in thinking the Xantia came with non-HA, HA only, HA with anti-sink and finally HA2 with antisink?

Grrr. I'll stick to my HA2.

AndersDK · Post by **AndersDK** » 05 Aug 2007, 22:54

Right Deian -

To clarify :

1) Xantia - in any model fitted with hydractive system - has the HA2 (hydractive generation II) system.
There never was a Xantia with HA (or HA1). That system was only found on XM, being the first model fitted with the hydractive system.

2) Not all Hydractive Xantia models have the antisink system

To summarise, there are the following Xantia suspension versions :

a) basic hydropneumatic suspension as found in low spec models. The same system asd known from GS, CX, BX etc.

b) basic system with added antisink system, incorporating a special antisink valve front & rear, and the rear antisink sphere recognised by its single small dia (3.5mm) connection pipe.

c) the hydractive 2 system with rigidness control incorporating a separate softness sphere added to each axle. The axle spheres are located on the HA valveblocks, recognised by their 2 large dia (10mm) pipes connecting to the wheel suspension units.

d) the high spec versions incorporating both HA and antisink systems.

e) the ultimate Xantia - the Activa model. Fitted with active antirollbar cylinders - and hydractive susension - and antisink.

Your V6 would have the d) option.

deian · Post by **deian** » 05 Aug 2007, 22:59

So what the HA found on the XM then?

AndersDK · Post by **AndersDK** » 05 Aug 2007, 23:10

deian wrote:So what the HA found on the XM then?

Thats the original hydractive system developed first off - hence the HA generation 1 - HA1 - or just HA.
As the XM came out late '89, and there never was a xantia before '93, then Citroen decided to correct known issues with the generation 1 hydractive system from the XM, and developed the hydractive system generation 2 - HA2 - which was fitted to Xantia on its introduction.
Also subsequent XM's produced were fitted with HA2 systems.

Main differences were refinements and reprogramming of the control computer - and the introduction of a separate valve block to each axle.

hubrad · Post by **hubrad** » 05 Aug 2007, 23:39

xantia_v6 wrote:I have the impression that your car is not Hydroactive 2, in which case the centre sphere is the so-called anti-sink sphere, and has no effect on ride quality, so don't expect any improvement on changing it.

On a non-HA Xantia, flat outer spheres or severe hieght error seem to be the only causes of a hard bouncy ride.

Thanks; I'm non-Hydractive, 5 spheres in total. The rear is very slow to rise anyway, so I was already thinking to replace the rear centre. Heights are good at least. Sounds like refreshing the LHM has just clarified the dodgy outer spheres. Best get working!

davek-uk · Post by **davek-uk** » 06 Aug 2007, 08:45

It could well be that your spheres are due for replacement; you'll have to gauge the ride quality, etc. But the spheres may not solve the problem of slow rear rising.

You have anti sink on your model, so the suspension never gets totally depressurised. If the spheres were shot, I'd expect the back to drop a little on start-up as the system relies on the pump to regain the pressure lost while standing. However, once working pressure is achieved, the back should raise at normal speed with good or bad spheres.

More often than not, slow height adjustment is the result of sticking linkages; and this is more prevalent on the rear as they are generally more open to the environment. The solution here is to clean and lubricate until everything moves freely.

You can actually get to the rear height linkage – just – without getting under the car by reaching in front of the rear wheel. You’ll see the end of the height adjustment lever rod and on high this will be pulling the first of the linkages forward. If you assist this with a screwdriver you should get the rear to rise quicker. To clean the linkages properly you’ll need ramps so that you can clean, lubricate and test while you are under the car.

Please maintain health & safety: the car can lower at an alarming rate when you assist the linkages, so make sure you have plenty of room…

hubrad · Post by **hubrad** » 10 Aug 2007, 19:46

Thanks for that Dave. I changed the front spheres with immediate excellent effect. Due to lack of time rather than enthusiasm (I do have ramps so access is not too bad.. I had BXs a couple of years back) I've booked into Citraulix in Bradford, who did much good work on the BXs in the past.
I think the car's sudden move to a really bumpy road must have been the last straw for at least the front spheres.. replacing the LHM just showed up the problem; replacing the fronts no whighlight the back as being relatively hard, so all in all I'm looking forward to a return to Magic Carpet Ride Land!
Much cheer HUGH