C5 Tourer suspension problems

[Another Citroen Saga]

Dear all,
I am a new member so do not quite know what I am doing or how things work.
In brief I have had Citroens since around 1991.
Pallas GSA, CX,XM,BXs, Xanthia and two C5 Tourers.
I am now on my third C5 Tourer - more of which below.
The first C5 had a steering rack leak at around 50,000 miles and the clutch was starting to go. Both done. A little later an empty parked car in a sloping car park, ran into my empty parked car- new tailgate lights etc needed and done. Not long afterwards I was stationary and indicating to turn right into a garage and someone ran into the back of me. Tailgate etc again and insurance write off.
C5 two . At around 52,000 miles steering rack leak and clutch going . Both done. At around 90,000 leak from pipe connected to the steering rack. Part not available and air condition in pipe from tractor used to do the job !
At 98,000 steering rack leaking again and clutch beginning to go. So that car and I parted company and C5 number three bought .

It is a 2015 plate. When viewed it was not rising and falling properly - very slow to go up and down. Fluid level checked and about half a bottle of LDS needed. Car better but still slow to adjust and very reluctant to come up after going to to the lowest setting .Yet it came up when driving and stayed in normal fine. The drive was not “magic carpet” and hard
I crossed fingers and bought the car thinking a set of new spheres would do the trick. Car then taken to an independent Citroen specialist up north as they had some spheres in stock. Garage helpful and two front spheres fitted and car was much better to drive. Rest of spheres were on order and when they arrived i took them to independent Citroen specialist i have used for years “down south”.
Remaining five spheres, done , LDS changed , new battery and alternator belt fitted. Car still slow to come up from low position and on ride home the whole of the car was worse than before. Garage said probably air lock. Citroen aerobics done and not much better. Repeated next day and LDS cap left off overnight with car at its lowest ( advised by garage). Car then bouncy and stiff and suspension fault and service light came up on dash.
Repeated aerobics next day and all lights gone and car better but not as it should be.
Took car to local garage ( not Citroen specialist ) and he bled nipples by the rear and front spheres . No obvious hiss or sign of air coming out.
Car okay but not as it should be as there is very little difference between normal and sport and ride is stiff with every manhole and pothole felt.

Took car to specialist ECU diagnostic place in Cardiff. No fault noted on suspension system. I should say here that the garage up north did quick diagnostic and a reading of “intermittent vehicle speed anomaly” fault was stored in the system but at time of his test “parameters all okay.”

Apologies for the long history.
In reading the forums there seems to be a number of potential causes of suspension problems
Fuses
Spheres and LDS
Height correctors , and possibly having the wrong height set at present somehow.
BHI/ ECU not reading signals
Sticking EVs in the BHI
Solenoid valve sticking or not working.
BHI Motor and pump not working properly due to corroded contacts
Leaking cylinder ram

As my car now rises and falls pretty well in all levels since numerous Citroen aerobics ; has no problems adjusting to variable speeds in the sense that it does get tighter and lower on motorways ; ECU has been diagnosed as fault free by specialist ECU garage ; I am at a loss to diagnose the problem of too rigid a suspension.

My guess is that there may be what Marc (Give me a break) mentioned about sticking EVs which would not show up on a diagnostic unless the car was driven for the test and put into sport and back and seeing the difference, (if any) , in practice as well as on the computer. And as I say the difference between the two on mine is not much.

Or perhaps it could be the solenoid ?

If it is sticking EVs can that be fixed ? Especially as the units are not supposed to be opened (although i saw one interesting video on you tube of the unit being completely disassembled ).
Secondly, as I am not a mechanic or engineer and will need to take the car to a garage does anyone know of a garage that has the right knowledge and experience of Citroens and C5 Tourer cars to do the necessary “detective” and repair work ?
I live in west wales ( about an hour from Swansea ) so anyone in this area would be great but I would go anywhere. For example i was wondering about Pleiades.
Thinking positively I do not have a steering rack leak or clutch to do - yet !!!
Finally I would also like to thank Marc for his measured and detailed explanations and information. He often puts extracts from what seem to be technical work books in the replies. Can these be bought or borrowed from somewhere. ?

Hope the above makes sense. You can see why I have adopted the “Another Citroen Saga” ( ACS) name
ACS

[GiveMeABreak]

Try bleeding it following the official procedure: It's here in a previous post of mine:

viewtopic.php?p=738860#p738860

See if that makes any difference.