C5 X7 Hydractive 3+ Strange Behavior

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Lekto
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Joined: 12 Jan 2021, 11:48

C5 X7 Hydractive 3+ Strange Behavior

Post by Lekto »

Hello guys,

I'm glad to see a French forum specially about my car because I have a problem who no body can explain. I'm so interresting and I kno so mich about this suspension but since my problem borned, I didn't find an issu or solve the problem. Maybe you can...

First, I'm sorry my engish and if another topic is already wrote but I'm new here and I didn't see yet topic like mine.

So, my problem is about comfort. My 7 spheres were already changed, LDS changed too. Just after this intervention about changing 7 spheres, the comfort was perfect. Few days after, the comfort has disappeared. I decided so the LDS because my car was borned 12 years ago. Just atfer changing LDS, the comfort was perfect again. Few days after, I decided to change the height of the car but just after this, the suspension was very stiff. I didn't use my car for 5 days so. When I used my car after 5 days of rest, the comfort was here again.
Actually, the comfort is not perfect but not stiff, like medium but I know it can be better. I'm afraid to change again the height.

Normal mode height is perfect, like 72 cm from floor to the top of the side car in the wheel area.

Please, I hope you have an idea about my problem.

Best regards,

Maxime

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GiveMeABreak
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Re: C5 X7 Hydractive 3+ Strange Behavior

Post by GiveMeABreak »

Hi Maxime

When you changed the spheres and the LDS fluid, did you bleed the system properly? Read my post here for the procedure:

viewtopic.php?p=648493#p648493

Lekto
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Re: C5 X7 Hydractive 3+ Strange Behavior

Post by Lekto »

Hello Marc,

Thank you for your reply.

Not exactly, I've just moved between four positions 5 times. But... Wait... I did it without remove the cap from the LDS tank... I thought air would automatically escape. I will do it next time...
Air inside the system can do this problem ?

Maxime

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Re: C5 X7 Hydractive 3+ Strange Behavior

Post by GiveMeABreak »

Just moving the suspension up and down will not bleed the system. The fluid as you probably know also operates the power steering, so when the LDS is emptied air will enter the system. Even the smallest amount can cause some issues, so better to bleed the system properly as recommended by Citroen.

Also read this post with a link to a label template you can print off for mechanics as a reminder to loosen the LDS cap when lifting the car off the ground when the wheels will be unsupported (hanging freely).

viewtopic.php?t=62058

The LDS cap is vented to allow some pressure release as the fluid is entering and leaving the system - you just need to get any air out of the hydraulic circuit that may have gotten in there.

Lekto
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Re: C5 X7 Hydractive 3+ Strange Behavior

Post by Lekto »

Many thanks Marc,

So you mean air in the system is normal ? You suppose to do this procedure quite often ?

Oui, I already know about the LDS cap during lifting. Great PDF but I'm afraid that the mechanics don't understand English ahahah.

The suspension comfort was present just after an intervention on the hydraulic system but it disappeared after... This would mean that the air was not purged and that at the beginning it was not serious but now it is?

I will do your procedure and keep you informed soon, thanks for your helping. I just hope it will solve my problem.

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Re: C5 X7 Hydractive 3+ Strange Behavior

Post by Hell Razor5543 »

I think that what Marc means is that, as the suspension height changes, air can be drawn into/expelled from the reservoir (as the LDS level changes), so that the reservoir is not put under undue strain. If the LDS is at the correct level there should be no air in the 'working' parts of the system, just in the reservoir.

Next time you know the car is going to have its' wheels hanging you might want to loosen off the cap yourself. That way you will KNOW it has been done, so damage should not occur.

Lekto
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Re: C5 X7 Hydractive 3+ Strange Behavior

Post by Lekto »

Perfect ! I understand !

I will do the procedure of Marc soon, I'll keep you informed.

BR,
Maxime

Lekto
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Re: C5 X7 Hydractive 3+ Strange Behavior

Post by Lekto »

Hello guys,

I've just finished the procedure and took the road for test. This is what I did :
- Level ground
- Release the cap from the LDS tank
- Setting suspension FULL UP
- Setting suspension FULL DOWN
- Move to lock (full but never stop) the steering wheel right and left 10 times (needed 5 min)
- Setting suspension NORMAL
- Cap on the LDS tank

I went on the road : nothing has changed

I didn't see any air bubbles because I couldn't see the level. Normal because I did not depressurize the system.

Any more idea ?

I want next time depressurize the system...

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Re: C5 X7 Hydractive 3+ Strange Behavior

Post by GiveMeABreak »

Ok, so at least you have properly bled the system Maxime and can rule that out.

Also, remember that the car 'remembers' and records the type of road surface you are on which you can see in live parameters - most people I know see this as 'Rough Road' or similar. You'll also find that ride quality improves with weight in the back on these. There's no variable damping on the X7 unlike the C6, so won't be that. I would just stick at it and see if it sorts itself out.

The only other thing I can think of is the fine tuning of the height correction - but I would not change anything there as it may lead to worse problems and takes a lot measuring and calculation to do this before entering the values in Diagbox. If it has been fine on and off, it won't likely be the height settings. It may be the height correctors - I had both of mine replaced after directional lights reported a problem and the height could not be changed intermittently.

Lekto
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Re: C5 X7 Hydractive 3+ Strange Behavior

Post by Lekto »

In a Facebook groupe, somebody depressurized the system and he noticed a very smooth suspension. This is my next plan.

About the height correctors, I think they are fine, I mean correctly programmed. I did it some weeks ago and I checked many times with good tools.

I have already checked what decided the computer BHI with my personal computer and it's recently in "Rough Road" but the state of Hydractive stay in comfort mode. An idea is actually in mind : Can the solenoid valves of front and rear remain blocked in sport mode ? I mean, Hydractive decided to put sport mode but at the moment to return in comfort mode, for BHI it's in comfort mode but in reality, the solenoid valves still in sport mode or between sport and comfort mode... I hope you see what I'm meaning.

I remember too, one day, suspension has become very smooth as it should be. Why ? I never find why...

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Re: C5 X7 Hydractive 3+ Strange Behavior

Post by GiveMeABreak »

Sport mode on the X7 (when using manual switch to select Sports Suspension) only keeps the 'Sport' parameters for longer than it would on Normal mode - so it would still swap back to comfort less often.

I think it is going to be one of those 'niggles' that will come and go randomly unfortunately.

Lekto
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Re: C5 X7 Hydractive 3+ Strange Behavior

Post by Lekto »

Yes I know but I meant like a mechanical bug. When I checked this, I was on comfort mode.

Doesn't matter, I will depressurize the system and of course keep you informed.

Yes I think too. At first I was coming here to hope have good advice and more information but yes... those 'niggles' that will come and go randomly unfortunately like you said

Lekto
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Re: C5 X7 Hydractive 3+ Strange Behavior

Post by Lekto »

Hello,

Some news about my problem.

I depressurized the system, the LDS level has been perfectly carried out and I didn't see some air bubbles during processing
I took the road for test and it's a little bit more smooth but not as I hoped.

I don't have any idea right now, so I think I will drive with this "problem"...

Hell Razor5543
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Re: C5 X7 Hydractive 3+ Strange Behavior

Post by Hell Razor5543 »

I wonder if a Citrobics session could help. This is like aerobics for Citroens, and can help to free up any sticking hydraulics. This is done with the engine running. First, take the steering slowly from full lock to full lock. Do NOT pause at any point (doing so could cause issues). About ten full lock to lock cycles should do; finish with the steering set to normal in line. Next take the suspension to its' fullest height and then down to its' lowest setting. Repeat this for another ten cycles.

This may not help directly, but if there is any air in the hydraulic system this should help move it towards the reservoir, and thence out of the system.

Lekto
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Re: C5 X7 Hydractive 3+ Strange Behavior

Post by Lekto »

I forgot to say that before reassembling the car I putted the cap of the LDS tank so I think there is no air in the circuit.

I already tried what you said once yesterday. Maybe 10 times as you said will fix it but the last time I varied the height several times, the suspension became very stiff.

Thank you for helping me guys