C5 X7 rear suspension fun.

[AJM C5]

OMG?! Not TtttRiffids?! But okay, once pit is built I will test first.

One last question for today tho svp. As I syphoned out the LDS from the tank direct, does the system need to be repressurised? I did put 2bar into the tank anyway but it made no difference (yes, I understand it should be 0.5bar, but WTH).

Actually, two questions.. Can the stiffness regulator be serviced/repaired?

Rgds....

[GiveMeABreak]

Have a look at the thread in the link below to C6 Owners. It uses the same setup as the X7 (although the C5 doesn’t have AMVAR).

There’s a chap who took his regulator valve out to inspect....

http://c6owners.org/plugins/forum/forum ... hp?2638.30

Don’t re-use reclaimed LDS as it can quickly become contaminated Alan. You will need to apply some pressure when all is back together and filled to recommended levels with LDS.

The system only needs a little pressure to start it off until the pump kicks in. Apart from the test I described (which doesn’t need depressurising as you are only working on the low pressure return pipes), when you start working on the circuit and if replacing or removing the regulator, you will need to depressurise. You can do this under the suspension ECU settings on Diagbox. But always disconnect the battery after you have depressurised it. If not the CAN network can trigger the suspension pump when a door is opened for example!

[AJM C5]

Well, the pit is built and ready. Now however, the pump will not start. Have applied pressure, tapped the pump, checked appropriate fuses, raise and lower switches toggled, rear height adjuster arm moved slightly... nothing.

It may be something I've done in Diagbox. Testing actuators... No response in DB, or no errors at least, then in DB raised the front, the front did raise as usual, not the rear when applying same command of course. Then I depressurised, that worked, nothing now though.... It won't do a thing even applying pressure with engine running.

Oh dear.

Thanks for link to regulator servicing, most useful.

[GiveMeABreak]

When the system is completely depressurised using Lexia it can take some time to re-pressurise. Assuming you applied the battery reconnection procedure, and applied some pressure to the tank, the pump should start to engage. If the pump is not operating, then suspect a fuse:

Pics and location in my post here: Fuse F1

viewtopic.php?t=61827&start=15#p599696

[AJM C5]

Correctamondo! The green 40amp F1 is blown, not discoloured or anything, but it's terminals are loose unlike the brown fuse next to it. It's a 32v fuse so tested the brown fuse with 12v to see if there's a tolerance level but no, that one is fine and passes the 6amps I used, but the Green fuse does not.

Maybe some of the LDS 'overflow' upset the pump..

Thanks once again Marc!

[GiveMeABreak]

Yes, it's an issue where if any LDS overspills from the tank, the fluid can drip down the back and enter the pump via the seal and cause a short circuit. I always plug the sides of the tank with a cloth when topping up so as not to let any drip down for that reason.

[AJM C5]

Hi

I will give the full story later, but where I'm at now is having finally removed the solenoid as per the C6 thread, and the spool, a needle dropped out onto a cloth on my lap which doesn't appear in said C6 thread. All else appears exactly the same. But I didn't see which way the needle was positioned in the spool... Pointy way in first?

Rgds
AJ

[AJM C5]

When finally wiggling the solenoid free of the regulator, the spool came out with it, it being corroded in just below the first large o-ring on the side of the next large o-ring. The C6 thread doesn't think these are moving parts, is he right.. And what pressure should one exert on the spool when putting it back in?

Thanks

[GiveMeABreak]

Sorry - I've been offline most of yesterday and today rebuilding some VMs and replacing some hard drives!

Ok, so here's a diagram of the rear Stiffness regulator. Hopefully you can make out the correct direction from the diagram depending on the view. So I guess pointed end in first.

"A" : High pressure inlet (Integrated BHI ).
"B" : Return to the reservoir (Integrated BHI ).
(1) Rear firmness regulator.
(2) Rear stiffener regulator accumulator.
"a" Variable firmness electrovalve.
"b" bleed screw(s) .
"c" Hydraulic isolation slide valve.
"d" Electrovalve slide valve.

[AJM C5]

No worries, this is not a contract service, you all gift your time and expertise and have lives outside. So...

Thanks for that, but it doesn't much look like the design or physical representation of the rear regulator & electrovalve on my C5. And what of the C6 thread, no needle mentioned, all else being exactly the same?!

Anyway I did put the pointy end of the needle in first, put things back together etc. I'm not saying it's because of the cleanup of the spool which was corroded into the electrovalve housing and poking out, it could be the heating and hammering on the regulator in the time spent trying to remove it, or the electrical connector even... But the rear of the C5 now raises, but only when tickling the rear height corrector. It holds its height when set, engine on or off overnight; when vehicle moves it drops. I will disconnect the dog bone to the ARB and statically set the HC it to see if that makes a difference when moving. Otherwise, any thoughts..?

Can Lexia help at this point other than displaying programmed settings for height..

Thanks

[GiveMeABreak]

Can you put her on normal height and take a few screenshots of the height settings and values?

You can undertake actuator tests to see what is going on as you command the car to raise and lower. Go into the suspension ECU and look at the parameter tests. There should be some tests you can look at.

[ActivaV6uk]

Ajm keep an eye on your pump, your issue is now basically the same as mine, the issue has been the the pump hasn't been providing any pressure while driving which is needed intermittently. The issue for me is the solid state relay on the pump has an intermittent power fault, this is quite common I've been reading on other forums that people have had this too. The car doesn't for some reason have a sensor on board to tell you there is pressure loss instead I've actually managed to drive it for about a mile on the bumpstops before you realise what it's done.

[AJM C5]

Hi Marc,

I disconnected and removed the dog bone and manually set the rear HC and all has been fine for two days over 40km with start & stops. I called into the nearest Citroen garage and he gave me a parts diagram avec prices. Tout alors! There is a new part that is not on my car, no 11 in picture. Only €180?! That on top of a new HC etc is €270+.

If I had faith in that I might have gone for it but I don't. That rear HC set up at least on my car if that is normal is possibly the worst design imaginable. The dog bone twists and turns, and even though the HC is bolted in firmly, it twists when the suspension goes up and down with it. No way can there be any solid reference point to it.

At this point I'm very tempted to install a manual potentiometer in the cab just in front of the lighting column and adjust it from there manually as and when. Don't know if it's mot'able, but I'd prefer that over replacing a potentially dodgy HC plus part no 11.

I contacted Citroen UK someplace to get the specifications for the HC - volts, current and Ohm rating, I don't want to undo the tape currently holding it in place if info is written on it.

AJ

[AJM C5]

Ajm keep an eye on your pump, your issue is now basically the same as mine..

Not sure it is the same problem at all. My pump appears to be working fine now, it pressurises when needed. My suspension issues were to do with the regulator and Height Corrector.

Thanks anyway.

AJ.

[GiveMeABreak]

Alan, that part (11) is the Anti Roll Bar Leer 5273N4. £169.91 inc. VAT over here.

When you say it's not on your car - it must have come away then as this is standard kit - so wither it's been knocked off or corroded and fallen off!

One here for £98

https://www.ebay.co.uk/itm/GENUINE-5273 ... 3379822525

I'm really not sure your idea will work - it is designed to be flexible and move so the suspension can adjust itself and maintain the ride height - it's not possible to manually adjust it every time the car rises and falls while driving and the values received by the suspension ECU are used in the firmness settings too. I an't see the system working properly (or safely) without it to be honest.

This particular setup has been in place since 2000 for the C5 using Hydractive 3 and a similar height correction system on previous hydraulic systems. Unfortunately it is exposed to the elements so copious amounts of marine grade grease is needed to protect all those parts.