non hydractive spheres for hydractive xantia

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

User avatar
xantia_v6
Forum Admin Team
Posts: 9052
Joined: 09 Nov 2005, 22:03
Location: France or NewZealand
Lexia Available: Yes
My Cars: -
1997 Citroen Xantia V6 (France)
1999 Citroen XM V6 ES9 (France)
2011 Peugeot 308 CC THP 155 (NZ)
1975 Jaguar XJ-S pre-HE (NZ)
x 825

Re: non hydractive spheres for hydractive Xantia

Post by xantia_v6 »

aneesh84 wrote: However I must test that the electrovalves are operational, before ordering. Since all my spheres are completely flat and I do not have access to the accumulator sphere, the bounce test is not an option for me. I do have a multimeter which i could use to test the electrovalves, except that I do not know where exactly to measure the voltages across. Is it near the front hydractive sphere. Or is there another convenient location in the circuit to measure the voltages?
The most convenient point that I know of is the wire to the front electrovalve, which is part of the assembly that the hydroactive sphere attaches to.
You need to test with the plug still connected to the electrovalve, as unplugging it will stop the system from working.

With the valve activated you should see 4-6 volts on that wire.
User avatar
Mandrake
Posts: 8615
Joined: 10 Apr 2005, 17:23
Location: North Lanarkshire, UK
My Cars:
x 664

Re: non hydractive spheres for hydractive Xantia

Post by Mandrake »

xantia_v6 wrote:
aneesh84 wrote: However I must test that the electrovalves are operational, before ordering. Since all my spheres are completely flat and I do not have access to the accumulator sphere, the bounce test is not an option for me. I do have a multimeter which i could use to test the electrovalves, except that I do not know where exactly to measure the voltages across. Is it near the front hydractive sphere. Or is there another convenient location in the circuit to measure the voltages?
The most convenient point that I know of is the wire to the front electrovalve, which is part of the assembly that the hydroactive sphere attaches to.
You need to test with the plug still connected to the electrovalve, as unplugging it will stop the system from working.

With the valve activated you should see 4-6 volts on that wire.
Or you could just unplug it, poke the leads of a 100 ohm resistor in the pins in the plug, and measure across the resistor. It doesn't take much to fool the ECU into thinking an electrovalve is connected. Anything from about 47 ohms to 470 ohms will work...

Of course all we're testing here is that the ECU works, the electrovalve itself could still be faulty - only testing with a known good sphere will reveal that. Things that can go wrong with the electrovalve are:

1) The internal back EMF diode can go open circuit or have a high resistance soldered joint. In this case an external (reverse connected) diode can be fitted in the wiring loom. I did this on my previous Xantia and mounted them on the wiring harness inside the black plastic box that houses the ECU. (Documented in a thread on the forum somewhere) I have a feeling this failure mode is quite common, but easy to fix with external diodes.

Symptoms of this problem will be that the suspension will only go soft for half a second during a hard to soft mode transition, so it will be stiff most of the time but do little unexpected "jumps" in height. It will also be impossible to depressurise the hydractive regulator sphere, making changing the sphere difficult if not impossible. (At least without a lot of oily mess)

2) The internal connection between the connector and the coil itself can get a dry joint - intermittent high resistance - which sometimes changes with temperature. I had this on a front electrovalve where it would work when cold but when hot it would keep dropping out. Symptoms are the ECU constantly cycling in and out of hard/soft mode every few seconds, or the suspension just being hard sometimes when it shouldn't.

There's nothing that can be done to repair this internally - the coil sleeve is fully moulded and can't be disassembled, so it requires a replacement electrovalve - or at least the coil sleeve part of it, which can be carefully separated from the rest of the unit. (Making it possible to make one good electrovalve out of one with a faulty coil/diode and one with a faulty needle valve...)

3) The needle valve can become pitted or worn to the point where there is high bypass leakage either in the hard or soft mode, but seemingly usually in the soft mode, and usually at the front of the car. At lower levels of leakage this will cause a variety of symptoms as it drains the reserve pressure at the accumulator fairly quickly when the engine isn't running.

Things like the car not settling after getting out of it if you wait more than 30 seconds between turning off the engine and exiting the car, (since all the reserve pressure has drained away and the anti-sink valves have closed before you get out of the car) or sometimes a loud "groan" after you get out as the anti-sink valves are just on the threshold of closing as the height corrector attempts to lower the car...

If the leakage is really bad it will cause the car to take a lot longer to lift up and the suspension will sometimes not switch to soft mode at all, or will switch in and out of soft/hard mode when bumps are hit causing unusual ride harshness. Sometimes the leakage is such that you can hear a hissing noise if you turn off the engine and listen close to the location of the electrovalve - if you hear a hiss that stops when the electrovalve shuts off after 30 seconds with the doors closed and the engine off you know you have a leaky electrovalve.

Although it's possible to disassemble an electrovalve its quite difficult due to locktite holding the thread together, its easy to break them instead of unscrewing them, and even though you can fully strip down the needle valve I'm not sure what could be done to fix pitting on the valve and cure the leakage. Again its probably just a case of getting a replacement. If sourcing a second hand one from a wreck, I would recommend a rear valve - front and rear are identical but front valves seem to fail a lot sooner, probably due to higher suspension pressures that they are switching and engine heat.

I wouldn't let a faulty electrovalve put off the original poster as they can be sorted out, but a faulty ECU would probably lead me to just fit standard spheres and be done with it...
Simon

1997 Xantia S1 3.0 V6 Auto Exclusive in Silex Grey
2016 Nissan Leaf Tekna 30kWh in White

2011 Peugeot Ion Full Electric in Silver
1977 G Special 1129cc LHD
1978 CX 2400
1997 Xantia S1 2.0i Auto VSX
1998 Xantia S2 3.0 V6 Auto Exclusive
aneesh84
Posts: 366
Joined: 31 Jul 2011, 22:29
Location: Lisbon, Portugal
My Cars:
x 28

Re: non hydractive spheres for hydractive Xantia

Post by aneesh84 »

Finally got a 100 ohm resistor and checked the voltage across the connectors, connected to the front electrovalve. Output= 0V. Tried opening and closing the doors, there was a spike sometimes, but the output always remained at 0 volts. Seems to me to be an ECU problem.


So finally I gave up the idea of having a working hydractive system. Now I just want a simple solution that will enable me to have a reasonably comfortable ride. I really need your opinion regarding the following options:

1) Four hydractive side spheres fitted with dead centre spheres
2) Four non-hydractive side spheres fitted with dead centre spheres

Which option in your opinion would provide a more comfortable ride? Is the roll effect of the non-hydractive spheres too bad ?
Xantia Estate 1999 2.0 HDI 110
C5 2005 2.0 HDI 138
Nissan Leaf 2018 40Kwh
User avatar
DickieG
Monaco's youngest playboy
Posts: 4877
Joined: 25 Nov 2006, 09:15
Location: Buckinghamshire
My Cars:
x 38

Re: non hydractive spheres for hydractive Xantia

Post by DickieG »

aneesh84 wrote:So finally I gave up the idea of having a working hydractive system. Now I just want a simple solution that will enable me to have a reasonably comfortable ride. I really need your opinion regarding the following options:

1) Four hydractive side spheres fitted with dead centre spheres
2) Four non-hydractive side spheres fitted with dead centre spheres

Which option in your opinion would provide a more comfortable ride? Is the roll effect of the non-hydractive spheres too bad ?
Have you listened for the Hydractive blocks buzzing when a door is opened (engine off)?

If you are abandoning the hydractive system you'll need to use non Hydractive spheres otherwise the ride will be very hard indeed.
13 Ram 1500 Hemi
14 BMW 535D Tourer
19 BMW i3s
06 C3 Desire 1.4
72 DS 21 EFi Pallas BVH
aneesh84
Posts: 366
Joined: 31 Jul 2011, 22:29
Location: Lisbon, Portugal
My Cars:
x 28

Re: non hydractive spheres for hydractive Xantia

Post by aneesh84 »

Yes there was no buzzing because there is no voltage output to the front electrovalve from the ECU.
Xantia Estate 1999 2.0 HDI 110
C5 2005 2.0 HDI 138
Nissan Leaf 2018 40Kwh
User avatar
Mandrake
Posts: 8615
Joined: 10 Apr 2005, 17:23
Location: North Lanarkshire, UK
My Cars:
x 664

Re: non hydractive spheres for hydractive Xantia

Post by Mandrake »

aneesh84 wrote:Finally got a 100 ohm resistor and checked the voltage across the connectors, connected to the front electrovalve. Output= 0V. Tried opening and closing the doors, there was a spike sometimes, but the output always remained at 0 volts. Seems to me to be an ECU problem.


So finally I gave up the idea of having a working hydractive system.
I wouldn't give up on the ECU just yet if I was you. A few more things to check:

1) Check the fuse feeding the hydractive ECU is actually fitted and tests ok.

2) Check the continuity of the wiring from the ECU socket right to each electrovalve plug to make sure there isn't a wiring fault or bad connection at one of the connectors. You can find which pin numbers on the ECU socket lead to the electrovalves elsewhere on this forum. (Or someone else may post them - I don't have the information anymore) Make sure you disconnect the battery before unplugging either of the plugs on the ECU. Check the continuity at the ECU plug end with the far end unplugged, connected to the electrovalve and connected to your 100 ohm resistor in turn to help identify if you have the right connections and that there is continuity.

3) Try connecting 100 ohm resistors to both front and rear electrovalve plugs simultaneously. A fault at either front or rear electrovalve will cause the ECU to disable both electrovalves at once. So for example if you are measuring at the front electrovalve with a resistor in its place, but the rear electrovalve (or the wiring to it) is faulty, the ECU will also disable the voltage to the front one.

A common problem is that the reverse diode within the coil unit is open circuit - the electrovalve will measure OK with an ohm meter, but the ECU will NOT be satisfied, and will shut down after half a second. A single faulty electrovalve will cause both ends of the car to be stuck in hard mode. Using a 100 ohm resistor at both front and rear at the same time will help identify this. (sorry, I should have suggested this the first time)
Simon

1997 Xantia S1 3.0 V6 Auto Exclusive in Silex Grey
2016 Nissan Leaf Tekna 30kWh in White

2011 Peugeot Ion Full Electric in Silver
1977 G Special 1129cc LHD
1978 CX 2400
1997 Xantia S1 2.0i Auto VSX
1998 Xantia S2 3.0 V6 Auto Exclusive
User avatar
Dommo
Posts: 1191
Joined: 11 Apr 2009, 09:43
Location: Stoke-on-Trent
My Cars: Current
07 C5 VTX+ 2.2 HDi 173hp
97 S1 Activa
06 Boxster S
93 XM 2.1 Turbo SD

Previous cars
91 Toyota Soarer UZZ32 Active Suspension
97 S1 VSX 1.9 Turbo D
99 Xantia Activa
98 2.1TD Xantia
99 306
x 19

Re: non hydractive spheres for hydractive Xantia

Post by Dommo »

Mandrake wrote:does anyone notice a difference in the amount of suspension dive in hard braking between a Mk1 Hydractive and a Mk2 Hydractive ? (Can't tell on the Mk2 I have as the spheres haven't been done yet so the ride is always hard :lol: )
Funnily enough, I used to have this with my S2 Activa, my dad always used to drive it with Hydractive turned ON because he didn't like the amount of brake dive from just normal driving, and he wanted hydractive to switch on just that little bit earlier to stop the dive. Although on my S1 VSX, there isn't any dive. I wondered if it was something to do with the brake bias due to the Activa having bigger front brakes but it could be due to the lack of a hydractive brake pedal switch.
aneesh84
Posts: 366
Joined: 31 Jul 2011, 22:29
Location: Lisbon, Portugal
My Cars:
x 28

Re: non hydractive spheres for hydractive Xantia

Post by aneesh84 »

Hi Mandrake, I will do those tests you mention tomorrow. However without proper support and knowledgeable help here, it is difficult for me to diagnose and solve even relatively simple problems. And I am a foreign student in portugal, so I only want a reasonably running car without spending too much time or money over it.

In case I am not able to sort out the ECU issue, I will just order 4 non-hydractive spheres whose specifications are as follows: 400 cc/55 bars/1.5 and 400/30/1.0.


However someone told me to also consider ordering citroen C5 spheres instead which have the specifications 500/75/1.9 and 500/40/1.25

I was told that a C5 sphere does not leak nitrogen and hence can last several times the life of a xantia sphere. Can you please also share your experience or opinion regarding the same.
Xantia Estate 1999 2.0 HDI 110
C5 2005 2.0 HDI 138
Nissan Leaf 2018 40Kwh
User avatar
DickieG
Monaco's youngest playboy
Posts: 4877
Joined: 25 Nov 2006, 09:15
Location: Buckinghamshire
My Cars:
x 38

Re: non hydractive spheres for hydractive Xantia

Post by DickieG »

C5 spheres certainly do appear to last longer but they generally cost around twice as much to purchase.
13 Ram 1500 Hemi
14 BMW 535D Tourer
19 BMW i3s
06 C3 Desire 1.4
72 DS 21 EFi Pallas BVH
User avatar
CitroJim
A very naughty boy
Posts: 49518
Joined: 30 Apr 2005, 23:33
Location: Paggers
My Cars: Bluebell the AX, Polly the C3 Picasso, Pix the Nissan Pixo, Propel the duathlon bike, TCR Pro the road bike and Fuji the TT bike...
x 6156
Contact:

Re: non hydractive spheres for hydractive Xantia

Post by CitroJim »

Beware that non-hydractive spheres on a hydractive car in hard mode will not be as soft and comfy as they are on a non-hydractive car. Best to try to get the hydractive system working if you can.
Jim

Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
User avatar
Chris570
(Donor 2020)
Posts: 1461
Joined: 12 Dec 2009, 14:10
Location:
My Cars:
x 29

Re: non hydractive spheres for hydractive Xantia

Post by Chris570 »

CitroJim wrote:Beware that non-hydractive spheres on a hydractive car in hard mode will not be as soft and comfy as they are on a non-hydractive car. Best to try to get the hydractive system working if you can.
+1
2006 C5 HDi 170
1998 Xantia Activa S1
1971 D Special
2006 C3 1.6 HDi SX,
CitroJim wrote: I'm a pink fairy
A 1/3 of Team WFA 'Clarkson'
User avatar
Mandrake
Posts: 8615
Joined: 10 Apr 2005, 17:23
Location: North Lanarkshire, UK
My Cars:
x 664

Re: non hydractive spheres for hydractive Xantia

Post by Mandrake »

CitroJim wrote:Beware that non-hydractive spheres on a hydractive car in hard mode will not be as soft and comfy as they are on a non-hydractive car. Best to try to get the hydractive system working if you can.
Good point. A standard hydropneumatic model "relies" (well, takes into account) the small diameter pipe permanently connecting the left and right sides, which increases the body roll but also increases independent wheel movement and ride softness, and helps keep the roll axis of the car more stable on uneven surfaces.

In a hydractive 2 car which is in hard mode the flow between left and right sides is blocked off and this is a significant part of what cuts down body roll on a hydractive model when entering hard mode for cornering.

Standard spheres on a hydractive 2 model with hydractive disabled will indeed ride harder than a standard hydropneumatic model, there will be less body roll in cornering but driving straight ahead on undulating surfaces the car will tend to rock side to side with the surface of the road.
Simon

1997 Xantia S1 3.0 V6 Auto Exclusive in Silex Grey
2016 Nissan Leaf Tekna 30kWh in White

2011 Peugeot Ion Full Electric in Silver
1977 G Special 1129cc LHD
1978 CX 2400
1997 Xantia S1 2.0i Auto VSX
1998 Xantia S2 3.0 V6 Auto Exclusive
User avatar
DickieG
Monaco's youngest playboy
Posts: 4877
Joined: 25 Nov 2006, 09:15
Location: Buckinghamshire
My Cars:
x 38

Re: non hydractive spheres for hydractive Xantia

Post by DickieG »

CitroJim wrote:Beware that non-hydractive spheres on a hydractive car in hard mode will not be as soft and comfy as they are on a non-hydractive car.
Unless of course you fit "softer spheres" from an alternative model such as for instance a BX.
13 Ram 1500 Hemi
14 BMW 535D Tourer
19 BMW i3s
06 C3 Desire 1.4
72 DS 21 EFi Pallas BVH
aneesh84
Posts: 366
Joined: 31 Jul 2011, 22:29
Location: Lisbon, Portugal
My Cars:
x 28

Re: non hydractive spheres for hydractive Xantia

Post by aneesh84 »

I finally ordered 2 CX turbo spheres(500cc 75bars ) for the front and 2 Xantia non-turbo (400cc 40 bar) spheres for the back. I know not the best option, but for now anything should be better than the rock hard suspension that i have. At a later date i will try to further diagnose the system.
Xantia Estate 1999 2.0 HDI 110
C5 2005 2.0 HDI 138
Nissan Leaf 2018 40Kwh
User avatar
DickieG
Monaco's youngest playboy
Posts: 4877
Joined: 25 Nov 2006, 09:15
Location: Buckinghamshire
My Cars:
x 38

Re: non hydractive spheres for hydractive Xantia

Post by DickieG »

Mandrake wrote:In a hydractive 2 car which is in hard mode the flow between left and right sides is blocked off and this is a significant part of what cuts down body roll on a hydractive model when entering hard mode for cornering.

Standard spheres on a hydractive 2 model with hydractive disabled will indeed ride harder than a standard hydropneumatic model, there will be less body roll in cornering but driving straight ahead on undulating surfaces the car will tend to rock side to side with the surface of the road.
I don't think that's entirely correct Simon as within the Hydractive block there is a bypass to allow fluid to flow from side to side independent of the state of the electrovalve. The flow of fluid through this bypass is controlled by a small ball bearing that closes if the sideways flow become excessive, so in simple terms slight variations in road surface heights on each side when driving straight ahead shouldn't make much difference to the ability of the car to remain level.
13 Ram 1500 Hemi
14 BMW 535D Tourer
19 BMW i3s
06 C3 Desire 1.4
72 DS 21 EFi Pallas BVH
Post Reply