C5 x7 Front suspension sags after a few hours

[C5maxita]

Hello everyone
I am the happy owner of a C5 X7 Tourer 2.0hdi 163hp year 2012 350,000km
Sorry for the language but I use the google translator as I know little English.

For many months, after a prolonged stop of 12/24 hours, the car has lowered by about 4/6cm only at the front.
When I open the driver's door the hydraulic pump starts and it goes back to the "park" position. when I insert the key and the ignition the car rises by two cm, therefore everything is in order.

The only problem is this front sag after a few hours of parking.
I noticed that even when driving the front suspension lowers more easily and sometimes the wheel touches the stone guard in the deepest holes.

There are no LDS leaks and the level measurement is always correct.

I replaced the 4 valves of the hydraulic pump but the defect remains.
I've tried disconnecting the return hose from the stiffness adjuster to the lds tank and it's not dripping.

I have no more weapons in my arsenal but I don't want to give up.

Can anyone help me?

Thank you

[Rp0thejester]

This is interesting, I'm sure someone here can help

[GiveMeABreak]

It is normal for the car to sink a little overnight, but as long as it auto corrects when the car is unlocked / door open, then at least it's working ok.

If you suspect it is not at the correct ride heights, has anyone changed the position of the height correctors? The slightest movement of the bracket can make a difference in the ride height - but the front height corrector is not easily accessible so I wouldn't think that likely.

So that leaves the actual suspension heights. To check these, you will need Lexia kit / Diagbox to check the actual heights against the reference values. If these are out of the range, then they may need a slight adjustment and to do that you must undertake the measurement procedure and calculations to get the value to enter into Diagbox which then makes the necessary adjustment.

[Rp0thejester]

Hmm, I was hoping someone would put it in layman's terms but I can't disagree with what he said.

[GiveMeABreak]

See my post here with procedure, calculations and diagrams:

C5 X7 (4 Cylinder Engine only) Hydractive Suspension Height Checking Procedure

[aerodynamica]

Reading the original post, I feel that he says the heights are right after it corrects the height when the door is opened and then secondly, the ignition switched on. That's also what mine does. I think he means is sinks down as though it is leaking internally after it is parked. I recall reading in the C6 owners forum that this can happen due to corrosion in the electro valve of the firmness regulator. I think it lets pressure seep through to the small overflow return pipe. My C5 occasionally sinks down at the front to a much lower (although not completely low) position, as does the rear but is isn't every time.

[GiveMeABreak]

I thought that too, but as he said he's already checked the hydraulic block return and there's no characteristic drip drip, I didn't mention anything. But of course if it's a slow leak then may not be immediately obvious....

[C5maxita]

thank you all for your interest.

I reply en masse to everyone.

The heights with the car running are regular.

I made the diagnosis with Diagbox and there are no errors.
I have tested the actuators (BHI pump valves) with Diagbox and they work fine.

the fact that it subsides after 12/24 hours is not regular at all..
The way it works (as it was until a few months ago) is that the car lowers by two cm when it switches off and stays that way.
When the door is opened or the ignition is switched on, it rises by two cm and this is its running position.

i read the PSA tech note about it and it says to check the LDS feedback from the central controller,
if it drips it's ok if it has a continuous flow it needs to be changed.
It doesn't speak if nothing comes out, as in my case, but I think, in principle, it works.

The technical note certainly refers to a complete lowering of the axle.