C5 - removing some suspension fluid

[pentoman]

Afternoon all,

I have a C5 X7 on hydractive III+.

For various reasons, known only to me, I decided that I wanted to top up the fluid just a little. With hindsight I wish I hadn't.

I purchased LDS from Total on Amazon. I carefully added 250ml, ensuring no dirt entered the system, and did a couple of up/down cycles.

However after a few miles of driving the suspension became noticeably stiffer. Suddenly I regret adding fluid and now I'm not sure if I can undo it easily.

Can anyone provide input? Can I remove a little fluid easily? Is the "basket" removeable from the resevoir?

Can anyone give an explanation for why the suspension became firmer with more fluid? Does more fluid equal firmer suspension? Have I confused the computers? Is there a level sensor, is the car actually aware of the fluid level? Could the fluid already in the car have absorbed water due to age?

The new ride quality is actually okay, comparable with any modern car... but it was even softer before, and I preferred it that way.

Russell

[bobins]

Whilst I can't shed any light on why your suspension has gone hard, this is the Citroen procedure for checking the LDS level:

Remove the cap from the LDS fluid reservoir.
Connect the diagnostic equipment to the vehicle’s diagnostic socket.
LEXIA diagnostic tool
Carry out a global test.
Start communication with the suspension ECU .
Select the menu : Depressurizing the system.
Follow the instructions displayed on the screen.
Diagnostic tool Diagbox
Successively select the following menus, on the diagnostic tool :

Customer delivery
Check of the suspension fluid level

Follow the instructions displayed on the screen.

N.B. : The depressurisation operation takes around 3 minutes.
Wait for the end of the depressurisation procedure.

Fill to the top of the fill level mark.


.........life was so much simpler with a Xantia

[myglaren]

Unlikely to be the additional fluid causing the increased hard ride. Was anything else done at the same time?
Mine is overfilled, like that when I bought it and haven't got around to sddressing that problem yet but it has been over two years now so not urgent, seemingly.

Do you ever perform Citroebics?
With the engine running select max height, allow the car to rise and settle for around 20" then select the lowest position and repeat a few times.

While this doesn't have the same benifits as earlier systems it does 'exercise' the struts etc.*

Also try running the car with a LOT of weight in it. I delivered far too much MDF to a workmate one afternoon and the suspension was greatly improved, the effect lasting several days.

*I had new tyres fitted last weekend and as I came away from the tyre fitters the car was groaning a bit, despite the tyres being fitted with the car at the recommended maximum height. A few iterations of Citroebics soon put that right.

My previous C5 was looking a little low on LDS. I purchased 1L Total LDS at the Northern rally that year and tossed it in. Made no difference whatsoever.

[pentoman]

Thanks hugely for those responses.
I do have access to an autologic diagnostic device which does give the 'depressurize suspension' option though I have been afraid to use it without further guidance.

RE: Citroëbics (I had to copy and paste your 'ë' there!). Yes I am aware of this. In fact it is one of the things that made me wonder whether my car needed more fluid. When doing Citroëbics I noticed that the car never reaches the top suspension position. It gets high but not quite high enough to settle and for the display to confirm reaching the position. The pump just keeps trying. This doesn't actually matter I suppose, but you know, I wanted things to be perfect. Hence topping up fluid, hence my current predicament.

I have only done one up/down cycle since topping up the fluid so I will try some more. It may just smooth itself out. I just wish I hand't done anything and had that super-soft ride. Now it's just regularly soft. Silly really, when I first had the car I thought the ride was too soft!

We're certain that extra fluid can't give a hard ride though? Is that for absolute sure so I can put that idea to bed?

This seems like a pleasant forum to hang out and discuss Citroëns. Particularly appropriate having returned from La Vie en Bleu French car day at Prescott Hill Climb yesterday.

[myglaren]

Unless the fluid gets air in it then it will not affect the ride, it is the spheres that control that aspect.
If the level was low enough there could be air in it. Unfortunately the C5 won't self bleed like previous models would.
As it is Hydractive 3+ then there could be an issue with the centre sphere, which is responsible for the softer ride. Perhaps it isn't being switched in when called to.

[pentoman]

Perhaps there was air in it before, and that was giving the softer ride. I think if there was air bubbles in the fluid then it means the fluid could compress and make the ride softer.

The 'sport' button certainly makes the car firmer and which makes me think the centre sphere is working.

I'll report back in a few hundred miles as I've only done 40-50 since top up.

[osx]

Try removing the LDS cap when the car is at the lowest height.