rear ride height changes whilst driving, any ideas?

[BrokenH4L0]

Hi Guys,

I have a 2000 reg HDi Exclusive Estate (Hydractive II) which I purchased recently. I have changed all eight spheres and I'm currently running Total LHM Flush. I have also recently bleed all the breaks to sort out the typical rear rising dramatically during braking, glad that's sorted now!

The problem I'm having is with the rear suspension ride height changes noticeably whilst driving. I Have done plenty of Citrobics (with no issues) which doesn't seem to have made any difference. Does any one have any ideas what could be causing it? I'm thinking possibly dirty ride height valve?

[MikeT]

I'm thinking possibly dirty ride height valve?

That's a very good starting point and exactly where I would be looking. Without regular maintenance, they will begin to stick so the general advice is to **once the car is safely supported** give them a good clean and lube, followed by a good physical workout of the spring loaded mechanism.

There's plenty of threads already covering this so I won't try and replicate them here (notwithstanding I can't remember all the hints and tips) but also check the plastic link, commonly named the dogbone, due to it's colour and shape. Being plastic it wears quicker than the other components and has a tendency to pop off if the corrector is sticking.

[BrokenH4L0]

Thanks Mike

I promise I have searched quite a lot on here but trying to find the exact same issue has proved difficult, I think CitroJim may have a similar issue.

The only thought I had was that it manually adjusts fine(using the lever) its only when actually driving that I notice it. I may strip down the ride height adjuster and give it a good clean out as per CitroJim's website.

The only other thing that crossed my mind was possibly a sticky electrovalve? I took the ones off my old car before it was scrapped and have stripped, cleaned and stretched the springs aswell as bench testing them both so may try swapping one over.

[MikeT]

It's the hydractive (and Activa) systems I'm unfamiliar with so can't offer any more support I'm afraid.

Jim's posts will almost certainly contain the answers you seek (there's not a lot Jim hasn't tackled yet ) though that will take a lot of reading so hopefully others with more knowledge will chime in and save you some time.

[BrokenH4L0]

Thanks again Mike,

Hopefully one of the Hydractive experts will be able to give their opinions soon?

[RichardW]

Does it change height suddenly - ie sinking or rising a significant amount quickly, then correcting to the right height?

[BrokenH4L0]

It certainly seems that way Richard, drops under acceleration and rises during breaking then will go back to normal, I would say it's air in the brake lines, but I bled them the other day (ran a good half a litre on each wheel)