Citroen XM Forum

The best way to tell if Hydractive is working is to fit tel-tale LED, or low wattage lamps to the electrovalve feeds.

I suspect you are correct as to why Cx spheres have been fitted and new spheres would resolve the issue of wallowy ride.

was following another XM this evening

couldn't keep up with him on the bends! it felt almost dangerous so i decided to back off before i crash

really really bad lean, i'll certainly be interesting in seeing how the new spheres perform

I once drove an Xm locked into soft mode. It felt like it was going to fall over round a roundabout...like a Cx, or Ds.

You have experienced why it's a fools errand to run with a faulty hydractive system and/or incompatible spheres and why, for safety, Citroen set the default for Hydractive to be hard mode.

To check the centre spheres are working and have gas, you should be able to perform a static bounce test.
Start the car and bounce each end a few hard down-up bounces.
Switch off, wait 30+ seconds until the electrovalve clunks.
Bounce again...it should be about 6-8 times stiffer.

No difference means the system is stuck in hard mode, or the centre spheres are flat, or if still very bouncy, the electrovalves have been wired to be permanently in soft mode.

To diagnose hydractive system issues you need known good spheres, either new ones, or the ability to check the spec and pressure of the ones you have.
Citroen spheres are the best, IFHS appear to be as good, but no "multicouche" option available, other brands often have less good sharp bump absorbtion, so can feel jittery and crashy.

As you have seen, an Xm excells at B road blasting, very few cars can keep up.

no difference

i think the centre spheres are flat personally, i do ocasionally have an issue with the car slamming to low at the front when i open the drivers door

i get the clicks when opening doors etc

new spheres will be interesting for sure

i've done 2,000 miles in this now since getting back on the road and it's been a very good car

think i might have sorted the diesel leak too, 4 pipes going to the fuel pump, managed to get half a turn on the lower front one

it does appear to be running down the front of the engine, covering the sump and goes everywhere just like diesel loves to do

still, rust prevention on the subframe so not going to complain

If tightening the injector pipe union hasn't fixed the leak and it is coming from the high pressure pipe, then you will need to remove that pipe and the associated delivery valve and re-seal the delivey valve thread.
If removing the delivery valve, be aware it is made up of a spring and stopper inside the metal tube, be careful not to drop any pieces.

Clicks, clunks and movement on door opening do indicate the Hydractive system is functioning, at least when stationary.

Don't be tempted to fit new Hydractive centre spheres with the Cx corner spheres still fitted, the car would be uncontrollable.

Looks like you are in for a set of spheres: easy job, the hardest part being to bleed the rear brakes after changing them, which is a very easy, one man, job...run engine, raise car, remove wheel, jam brake pedal down, open bleed nipple.

To easily remove the centre spheres you must leave the engine running while lowering the car, then open the 12mm pressure releif on the regulator, then switch off the engine.
I find, if you follow that process, most of the spheres will unscrew by hand, or after a clout with a lump hammer.

As long as the rear cylinder locating dowels haven't rusted away, the rear cylinders cannot spin round, so those spheres can also be removed while the system has no pressure in.
The system pressure is what makes spheres difficult to remove, as it locks the screw threads very solidly.

Opening the regulator pressure releif, while not strictly necessary for corner sphere removal, removes any residual system pressure, so unlocks the threads and significantly reduces the fluid spillage on sphere removal.

When buying an Xm with unknown history, one should expect to have to regas/change the spheres to gain the correct ride quality. They are often overlooked, even by enthusiasts.

oh don't worry, i'm replacing all the spheres

now the leak, it seems to be leaking less, but there does seem to still be a drip, albeit this could be pooled stuff leaking off.....going to take it for a decent run tomorrow and see

i really am not comfortable driving it fast, it really feels incredibly unstable, and i imagine it would very easily lose traction with the way it leans

it's not even that comfortable either, the float is excessive, it bottoms out much too easily and just feels very wrong

Previous to scott owner... wanted a floaty glideing ride for its trip to spring and back on the owners final journey..

My guess to why the cx spheres were fitted. He was factuated with having a.smooth guide and waft rather then a stiffer handling ride, and I mean cx quailty not usuall xm style of ride.

i want it to work correctly, i ensure everything in my car is as built and working correctly so you can experience them to the full

Absolutley... there's soft.. there's riding correctly and there's dangerously too soft..

The c5 spheres to me feel perfect payoff. Not too soft like cx spheres and not hard like hydractive activated. I like it a lot