c5 x7 hydroactive suspension failure query

[Bigzed]

Hi All,
What I am experiencing is the failure of the hydroactive suspension, after jacking up one wheel of the car. Say to change the wheel.
My procedure is:
1. Confirm suspension is in the normal height position.
2. Loosen wheel nuts
3. Jack car on trolley jack at the lifting point.
4. Remove wheel nuts and wheel.
5. Replace wheel, and install nuts
6. Lower car.
At this point I cannot remove the trolley jack as the car is sitting really low ( suspension completely compressed)
turning on the ignition / running the engine and manually trying to raise the car does nothing. It still is fully compressed.

The only way I have found to raise the car is to use diagbox.
Diagbox tells me suspension has fault codes, after clearing them the suspension works as normal.
I can then remove the trolley jack, tighten the nuts and drive the car with fully working suspension ( no error codes in diagbox)

Surely this is not normal, and as Citroen intended.
This makes me very nervous about getting a puncture, or having any wheel / brake work done at an non approved citroen garage.
I understand that if you raise the car on a lift (all 4 wheels hanging) that you should remove the cap on the LDS tank, but is this required for a single wheel.

Any suggestions on why this should be happening, or what I may be doing wrong, would be greatly appreciated.

[Lenny]

I always raise the suspension to it's highest setting before jacking the car.
I don't know if that's wrong or right but it's what we used to do with BXs and Xantias back in the day.

[dulenator]

Maybe you have some small leak somewhere in the system. I had a bad (rusty) strut shaft (or whatever it is called), and when the car was lifted, the strut would expand beyond the bad part and release the pressure. After that, it needed the standard stuff to get things going - applying some pressure to the tank.

At the time, I thought that's how hydraulic suspension works until I talked with other C5 owners and realised I needed money for the parts.

[Sloppysod]

Yes, I ALWAYS put the car in the highest position, and then jack it up, OR, place an axle stand under the car. When using the axle stand you can then lower the suspension to lift the wheel.
Unlike mechanical pumped citroens of yester-year, the electric pump will take a while to raise the car again I'd the suspension has dropped.

What errors does diagbox give you?

[PaulC5]

It is usual on hydractive Citroens to raise the suspension to max height with the height switch and the engine running before using a jack. Then switch the engine off and take the key out of the ignition and use the jack. This is probably in the car hand book and I seem to remember it being in our C5 hand book. Failure to do this can lead to problems with the suspension and is something that should be told to garages/tyre fitting places in case they do not know. Also on the C5 X7 the LDS tank cap should be slackened off if the wheels are to be left hanging since if not done the tank can split.

Do not go under the car without using axle stands since there is a risk the suspension can quickly drop to a low level and squash anyone underneath.

[Kees]

It's just doing wrong!!!
You have to put the car in the HIGHEST position before you Jack the car up.
It doesn't matter if you put it just for one wheel..what now happen is that the system sees that one wheel is to high, and release the lds fluid, because the system want to correct the high.
Then when you lower the car, there is nothing in the struts to keep the car up.
So, next time, always put the car in the highest position
Greetings,
Kees.

[PaulC5]

Just had a look in a hand book for a C5X7 and there is a full page on 'Removing a wheel' which clearly states the suspension has to be raised to max height before jacking and left there while the car is on a jack copied as follows:
--------------------------------------------------------------
Park the vehicle on stable, firm ground that is not slippery. apply the parking brake.
 If your vehicle is equipped with "Hydractive III+" suspension, with the engine running at idle, adjust the ground clearance to its maximum height.
 Switch off the ignition and engage first gear or reverse gear depending on any slope (for a vehicle with automatic gearbox, select position P).
 If your vehicle is fitted with "Hydractive III+" suspension, position the chock, whichever direction the gradient may be in, in front of the front wheel diametrically opposite to the one to be replaced.
-----------------------------------------------------
Before positioning the jack:
 Always adjust the vehicle’s ground clearance to the "maximum height" position and retain this adjustment for as long as the jack is under the vehicle (do not use the hydraulic adjustments),
 Immobilise your vehicle on horizontal, stable and non-slippery ground,
 Ensure that any passengers have left the vehicle and are in a safe place.

Never get underneath the vehicle if it is supported only by the jack. The jack and all of the tools are specific to your vehicle. Do not use them for any other applications.
Have the original wheel repaired and refitted as soon as possible.

[Bigzed]

Thanks Guys for all your replies.
I will follow that procedure and let you know if that changes what I am experiencing.
Also I will review the owners manual again, to see if I can find that info.

[Stickyfinger]

Yes, I ALWAYS put the car in the highest position, and then jack it up, OR, place an axle stand under the car. When using the axle stand you can then lower the suspension to lift the wheel.
Unlike mechanical pumped citroens of yester-year, the electric pump will take a while to raise the car again I'd the suspension has dropped.

What errors does diagbox give you?

This should never be done with X7 C5's as it can damage strut seals.

[Armidillo]

Alasdair, perhaps you'd better be more specific about which approach can damage strut seals.

[Sloppysod]

This should never be done with X7 C5's as it can damage strut seals.

Alasdair
How?.… which part, full height and jack-up or full height and lower suspension onto axle stands?

[Stickyfinger]

The vacuum/pressure it creates within the system.

The (fluid return) system on C5x7's and C6's is not at all like that on Early Mk1/2 C5's and cars before that.

There is a reason Citroen specificity say raise the car to its full height in the handbooks. For example, to fully depressurise the system correctly a Lexia is needed, this shunts the various valves to allow dissipation of said pressures and vacuum in the various parts of the system.

[Armidillo]

So are you saying don't use an axle stand under one corner, then lower the suspension? Not clear which of Sloppysod's options you are objecting to (& I don't think Mr Sod knows either ).

[Stickyfinger]

I would not be happy to use only an axle stand on ONE corner, I would always use 2 (on the same side or front/back) and remove both wheels on a C5x7 when the suspension was raised prior to lowering it. I would not be happy allowing the car to lean at such an angle on axle stands (if on one side) however so would not go under it and would not use the sill jacking points for such an operation.

[Bigzed]

Ah I am such a numpty.
Chapter 11, page 166 of the owners manual states (with RED WARNING triangle)
" Always adjust the vehicle’s ground clearance to the "maximum height" position and retain this adjustment for as long as the jack is under the vehicle (do not use the hydraulic adjustments).

I have just used the max height setting, prior to jacked the car up to lift the wheel of the ground, placed an axle stand, and lowered onto that, then removed wheel.
After replacing the wheel, removing axle stand, and loweing the jack. the suspension was still up. , and after staring the car, manual adjustment of the suspension works as intended.

Hope I havent damaged anything whilst using the incorrect jacking procedure.

Thanks again guys for your assistance.