HA2 hard suspension partly solved

[JohnCKL]

My 96 XTD with hard HA2 suspension was partly solved when plugged into the Proxia computer which shows my steering angle was off about 41 degrees to the right. Some time ago I've taken out the steering sensor to access the dash lights. Without the Proxia, its impossible to tell if the angle is correct as there are no markings on the sensor. Now with the sensor set approximately to the right angle, suspension is softer and more comfy. However, the front bounce test is still too firm and need to replace some suspension bushes I suspect. All spheres regassed, so its not a problem of low pressure. Once new bushes are installed, I suppose it should be better. May I ask how much bounce for the front suspension for HA2? Mine only went probably 3cm down, too stiff.

[Mandrake]

My 96 XTD with hard HA2 suspension was partly solved when plugged into the Proxia computer which shows my steering angle was off about 41 degrees to the right. Some time ago I've taken out the steering sensor to access the dash lights. Without the Proxia, its impossible to tell if the angle is correct as there are no markings on the sensor. Now with the sensor set approximately to the right angle, suspension is softer and more comfy. However, the front bounce test is still too firm and need to replace some suspension bushes I suspect. All spheres regassed, so its not a problem of low pressure. Once new bushes are installed, I suppose it should be better. May I ask how much bounce for the front suspension for HA2? Mine only went probably 3cm down, too stiff.

Hi John,

That is very strange, because in theory it shouldn't be possible for the steering wheel sensor to be 41 degrees to the right - because it is an LED chopper sensor which can turn infinitely in either direction, and the computer uses a heuristic algorithm to determine the correct straight ahead position and is thus self-calibrating...... (This is according to the service manuals... they even describe the algorithm which is used to determine the straight ahead position)

Regarding the bushes, exactly what bushes are you thinking of replacing ? The only bushes in the front suspension are the ones that support the lower arm, and unless they're totally stuffed (causing gross problems with steering tracking) then they are not going to affect the ride quality.

When you say the front only goes down 3cm in a bounce test, is that in the soft or the hard mode ? I presume you know how to do a stationary bounce test in both soft and hard mode ? Soft mode is with the engine idling, hard mode is 10 seconds after the engine is turned off with all doors closed.

In soft mode if I sit above the radiator the suspension bottoms, however in hard mode it only goes down about 25mm. Make sure that you can notice a big difference in bounce stiffness between the soft and hard modes otherwise you may have a hydractive 2 related problem. (Either centre HA sphere faulty, HA valve faulty, or computer not activing the valve)

I too am trying to solve harsh ride on my HA2, and all my front spheres are on pressure, and it passes a bounce test with flying colours, and yet the ride is still harsh and poor on uneven surfaces. If you see my other thread relating to struts you'll see that I think the strut cylinders themselves are to blame on my car...

Regards,
Simon

[JohnCKL]

Hi Simon, that was what the Proxia indicated. When my steering was about 40deg to the right, Proxia shows 0 and when turning it straight on, Proxia shows about 40deg. The Proxia did not report it as a problem, though. Is it because before the Proxia was plugged in, the steering wheel was not straight ahead but was an angle of 40deg? Must send for checking again.

Perhaps the lower arm bushes are damaged as there are some clonking sounds esp. when cornering. Front goes down 3cm in soft mode when engine idling, so something is faulty. All spheres regassed, then perhaps its HA valve or ECU problem. What are the price of new struts at your place?

[Mandrake]

Hi Simon, that was what the Proxia indicated. When my steering was about 40deg to the right, Proxia shows 0 and when turning it straight on, Proxia shows about 40deg. The Proxia did not report it as a problem, though. Is it because before the Proxia was plugged in, the steering wheel was not straight ahead but was an angle of 40deg?

Could be... perhaps the steering was at that angle when the key was turned on ? The algorithm for centring the steering sensor requires the car to be driven some distance (10's of metres) to calibrate the straight ahead position. So ideally you would drive the car down the road and back before plugging it in to test.

Must send for checking again.

Not sure that would get you anywhere, as as long as the steering wheel sensor is registering angle changes correctly it should self-calibrate the straight ahead position when you drive the car normally.

Perhaps the lower arm bushes are damaged as there are some clonking sounds esp. when cornering.

If you're getting clonking, the first thing to check would be the balljoints on the rollbar droplinks - they're a prime candidate for wearing out and starting to clonk. The lower balljoint on the left droplink on mine is just starting to clonk a bit and I can get it to click slightly just wiggling it by hand, so I'll be replacing that soon...

Front goes down 3cm in soft mode when engine idling, so something is faulty. All spheres regassed, then perhaps its HA valve or ECU problem.

So there is no change in how stiff it seems to be at the front between soft and hard ? Do you notice a difference at the back ? If the back is ok and the front isn't, its unlikely to be the computer.

When you turn the key off and close the doors and listen near the front of the car do you hear a loud click about 10 seconds later ?

One possible fault, which another forum member bernie had on his car is that the internal back-emf protection diode which is built into the solenoid itself failed, and this apparently can stop the solenoid activating, even though it has power applied.

What are the price of new struts at your place?

Well over here Citroen parts are very expensive, I've been offered a pair of new condition but second hand struts (cylinders) which have only done 10,000Km for $300 NZD each, I believe the new price is nearly double that. Hence the reason for wanting to be VERY sure that I've eliminated all other possibilities first...

Regards,
Simon

[JohnCKL]

Thanks for your advice, Simon. When in hard mode, the front hardly moves down when pressed, maybe only 5mm, if any. Definitely a problem. When turning off the key, there's no clicking in front but a whining at the back about 20 sec, I think before there's a click but I think its just the rear, not the front. Struts here are at least US$260 each new.

[Mandrake]

Thanks for your advice, Simon. When in hard mode, the front hardly moves down when pressed, maybe only 5mm, if any. Definitely a problem. When turning off the key, there's no clicking in front but a whining at the back about 20 sec, I think before there's a click but I think its just the rear, not the front. Struts here are at least US$260 each new.

Hi John,

Because of the very stiff damping in hard mode you won't be able to bounce it very far, 5-10mm would be normal during a press bounce test, however try to get an assistant with a measuring tape to measure how much it drops when you sit your entire weight on it and it should be more like 20mm in the hard mode.

However it does sound a lot like your front hydractive solenoid is not working. Both the front and rear solenoids should whine when active (although you can only hear this with the engine off naturally) and make quite an obvious "click" when they turn off and stop whining when deactivated.

With the engine off and doors closed, listen close to the front of the car near the radiator while an assistant opens a door, you should hear a click, and then a whine, then 10 seconds after they close the door you should hear another click and the whine stopping. Thats if its working properly of course.

The rear solenoid is forward and to the right of the spare wheel, you can get easy access to it with the car backed up on ramps and the spare wheel carrier removed.

The front solenoid is on the unit at the bottom left of the radiator, and is the bit sticking out the side with the cable connected to it.

It is actually possible to manually activate it for testing. You'll need some small test leads with alligator clips, a 10 watt 15 ohm resistor, a 5 amp fuse, and a multimeter.

With the engine off, unplug the cable going vertically up into the side of the unit by squeezing the clip and sliding it downwards, and clip a couple of alligator clip leads onto the terminals. (You might find this easier with the car driven up onto ramps, and be careful that the clip leads aren't shorting together)

Now you have to figure out the correct polarity to use, and this is very important because there is a reverse protection diode built into the unit and if you get the polarity wrong with a direct 12v feed you'll most likely blow up the diode.

Connect the solenoid to 12v through the 15 ohm resistor (and keep the 5amp fuse in line as well in case of shorts during the testing process, otherwise you could easily set fire to your clip leads) and measure the voltage across the solenoid, if you have the polarity correct you should measure about 2.5 to 3.5 volts, if you have it backwards you'll measure less than one volt. Once you have it the right way around short out the resistor for about a second and you should hear a click, and the solenoid should be on.

Note: if you measure the same voltage both ways around, eg 2.5 to 3.5 volts, then the diode built into the solenoid could be faulty (open circuit) as bernie's was, and you may have found your problem already. If the diode is open circuit the solenoid will activate just fine with the manual test described here, but will fail to activate when driven by the computer, due to the computer driving it with pulses.

To deactivate it disconnect the power. It should click again at this point. The reason for this process with the resistor is that it is designed such that it needs the full 12 volts for half a second to switch the solenoid on, and yet it can't withstand 12 volts indefinately without overheating, so they drop it to 3 volts for longterm running, but although 3 volts is enough to KEEP it active after already being activated with 12 volts, its not enough to activate it in the first place.

You won't hear any whining during this resistor test, only a click, as the whining is caused by the computer pulsing the voltage at about 1Khz.

If you measure the current drawn with an ammeter it should be approximately 3 amps with the full 12v (don't run this for more than a few seconds) and about half an amp through the resistor.

If you measure these currents ok and yet you don't hear it clicking at all there could be a mechanical fault with the solenoid.

If you do hear it clicking, try the process again with the engine running this time, and once you activate it and have it running off the 15 ohm resistor, try a bounce test.

Regards,
Simon

[JohnCKL]

Wow, that's quite a detailed electrical testing, something I'm unfamiliar with. However, I'll see what I can do. Thanks again. Hopefully can find out the fault, most probably as you've pointed out, the front hydractive valve as it is also leaking LHM as well as at the brake valve side.

[JohnCKL]

The culprit in my case is the ElectroValve1 in front, behind the radiator. Apparently there was an leak, internal or external (visually yes). Got a used EV, opened it up, cleaned with oil and air blasted to dry it. Changed all the black O-rings except the green ones on the solenoid. Can't find those. There's actually a sieve at the end of the solenoid which I could not
open up. It was dirty with brown like deposit and can't even see the sieve, cleaned it up, then realised there was a filter. Replaced the EV, use back the old HA sphere and my XTD got magic carpet ride again.

The hydraulic pump no longer clicks every few seconds, it now clicks every few minutes. When starting the car, the STOP light goes off in just a second compared to previously, have to wait 2-3 minutes for it to go off. Pressing the front of the car when its idling, can feel the dampening whereas previously, can just feel hardness, the car barely going down 1cm, now can go 2cm, not that much, maybe still got room to improve. Now can feel the car absorb the small potholes and feel the floatiness of the ride around corners. I think its a combination of dirty LHM and cleanliness of the components. Will have to throw away the old dirty LHM, use Hydraflush again (last time was 3 years ago), open up the EVs, HCs etc. to clean them up.

I've got some pictures, how do I post them up?

[bernie]

Hi John

Go to
http://photobucket.com

Register

Post your pictures to the web site

Then post a reply on this site with the link to your picture

I'm eager to see

Bernie

[Mandrake]

Well done!!

I'm also eager to see pictures. I've been along a very similar path in the last week, my front valve is also leaking internally, although not nearly as badly as yours by the sound of it...except I was unable to dissasemble the solenoid unit itself after removing it from the main hydractive block - for fear of breaking it and not having a spare, so I would dearly love to know how you got yours apart. Yes the "sieve" on the end is a filter.

Will post more soon...

Regards,
Simon

[JohnCKL]

Loaded up the pictures at http://photobucket.com/albums/c358/johnckl/
See if you can access it. I can't open the solenoid either but I did open up mine accidently when taking the old one electrovalve out. Theres 2 springs and a plunger inside the solenoid and you have to remember which end fits where. Hope I got it right. From the picture of the disassembled parts, you can see some O-rings but not all of them, some already fitted on. The parts which came out, there are 2 sides to them, so do remember which side is up. I think I got them right. Most probably the new O-rings plugged up the internal leaks. My next step would be to dispose of the old LHM, put in Hydraflush and clean rear electrovalve2, height correctors and see if the pressure regulator and anti-sink valve can be disassembled and cleaned too. Fit them with new O-rings and see if it can be further improved.

[Mandrake]

Ok, a bit more time on my hands to write a decent reply...

The culprit in my case is the ElectroValve1 in front, behind the radiator. Apparently there was an leak, internal or external (visually yes). Got a used EV, opened it up, cleaned with oil and air blasted to dry it. Changed all the black O-rings except the green ones on the solenoid. Can't find those.

Where are the black o-rings you refer to ? Are they inside the main control block or inside the solenoid ? And when you say you can't find the green ones do you mean you can't find suitable replacements, or that you don't have any green on yours ?

I notice in your close up picture of the solenoid you have the green o-rings removed. (At least they're green on mine) The small o-ring is very important, and prevents leaking from the HP inlet to the control slide valve in the main unit - if this seal leaks the valve will leak from inlet to overflow when the solenoid is in the OFF (hard) mode.

Apparently this happened on some early models without anti-sink and could cause the car to go down within seconds of turning the engine off.

The large o-ring is the seal that prevents external leakage. Was this leaking on your original one ?

There's actually a sieve at the end of the solenoid which I could not
open up. It was dirty with brown like deposit and can't even see the sieve, cleaned it up, then realised there was a filter. Replaced the EV, use back the old HA sphere and my XTD got magic carpet ride again.

The hydraulic pump no longer clicks every few seconds, it now clicks every few minutes. When starting the car, the STOP light goes off in just a second compared to previously, have to wait 2-3 minutes for it to go off.

Wow, seems like yours had a LOT of leakage, so much so that the pump could barely keep up. A bit more leakage and your car may not have been able to rise at all at idle.

If the regulator cycle time is several minutes now, there is probably no excessive leakage in the rear hydractive solenoid, so you may not need to touch that one unless you suspect the rear suspension is sticking in hard mode sometimes.

Pressing the front of the car when its idling, can feel the dampening whereas previously, can just feel hardness, the car barely going down 1cm, now can go 2cm, not that much, maybe still got room to improve.

Ok, so now the centre sphere is actually working, but it sounds like the centre sphere also needs gassing or replacing, it should move a lot more than 2cm if you sit on it.

Now can feel the car absorb the small potholes and feel the floatiness of the ride around corners. I think its a combination of dirty LHM and cleanliness of the components. Will have to throw away the old dirty LHM, use Hydraflush again (last time was 3 years ago), open up the EVs, HCs etc. to clean them up.

Only open up the height correctors if you suspect they are not correcting the height properly. If they adjust the height to the correct height ok consistantly in both an upwards and downwards correction to within about 10mm there is nothing wrong with them.

Stripping and cleaning a height corrector is no harder than the Hydractive unit, BUT getting the front height corrector out of a Xantia is EXTREMELY difficult due to the location. Unless you have a 4 post hoist I'd suggest not doing it unless really necessary, I was foolish enough to attempt it with only drive on ramps and it was an all day job to get it out and refit it, which involved considerable swearing and bruised knuckles. The actual cleaning didnt take long...

I agree that contamination of the oil with dirt and/or other foreign particles is probably what causes the problems with the needle valves in the hydractive solenoids. An extra reason to keep the LHM clean on Hydractive models......

On mine it was causing the regulator to cycle every 10 seconds, and it was audibly hissing, I removed the whole unit and stripped it to pretty much what you show in your 5th photo, except I didnt remove the star key plug out of the main unit, nor did I replace any o-rings.

Using compressed air into the HP inlet port (the steel pipe in line with the filter input of the solenoid) and activating it with a battery I was able to prove that the solenoid was leaking badly from one end to the other in the on position as I suspected.

After half an hour of attempted cleaning through the ports using petrol and later oil with compressed air, (since I was unable to strip the solenoid and didn't have a spare in case I broke it) I thought I had it fixed - the leakage stopped, and I refitted it back in the car.

At first the problem seemed to be solved - no hissing, regulator cycle time in excess of 5 minutes (!) and able to switch from hard to soft and back again with the motor off (by opening doors) at least 10 times at the front, something it could NEVER do before.

Also the symptom of the car popping up like a cork when going from full height to normal height dissapeared as I hoped it would.

Unfortunately after going for a short test drive, the internal leak seems to have returned, although perhaps not as badly as before. There must still be some foreign particles caught in the solenoid which I'm unable to clear out, so it looks like I'll have to get a replacement solenoid for the front after all. Luckily the rear one seems to be fine.

But at least for the time it lasted I was able to prove that the solenoid was the source of leakage and was responsible for some of the symptoms I was noting, and it gave me a chance to give the main unit a good clean as well.

Regards,
Simon

[Mandrake]

Loaded up the pictures at http://photobucket.com/albums/c358/johnckl/
See if you can access it. I can't open the solenoid either but I did open up mine accidently when taking the old one electrovalve out. Theres 2 springs and a plunger inside the solenoid and you have to remember which end fits where. Hope I got it right.

So which did you open accidentally ? The faulty one you removed, or the new one you were putting in ? Did it break it or was it just very tight, or did it have some kind of loctite on the threads ?

It looks like it should unscrew between the nuts at both ends, but I was unable to do it without applying more pressure than I thought safe, especially when I have no spare and no hope of getting one locally.

From the picture of the disassembled parts, you can see some O-rings but not all of them, some already fitted on. The parts which came out, there are 2 sides to them, so do remember which side is up. I think I got them right.

Are the "parts which came out" the items in picture 1 ? If so, those are the damping valves And yes, the small hole side faces outwards as you show in your picture.

If the damping valves are not symetrical and you reverse them, it will swap the bounce and rebound damping characteristics - not a good thing to do, especially if only one was swapped by accident.

Most probably the new O-rings plugged up the internal leaks.

Which o-rings do you think fixed the problems ? Are you sure it wasn't changing the solenoid that fixed it ? On my one at least, the source of the leakage is the seat of the needle valve where it exits the overflow pipe - in the ON mode the seat doesn't quite seal properly, and as far as I know no o-rings are involved there. Of course yours may have been leaking at the o-rings as well.

My next step would be to dispose of the old LHM, put in Hydraflush and clean rear electrovalve2, height correctors and see if the pressure regulator and anti-sink valve can be disassembled and cleaned too. Fit them with new O-rings and see if it can be further improved.

Whoa there, don't get carried away

I wouldn't go stripping down the pressure regulator, if you aren't familiar with whats inside it and havn't done one before you will get into BIG trouble.... there is a VERY BIG SPRING that can potentially seriously injure you if you attempt to dissasemble it incorrectly or without the necessary tools. DANGER!

Overhauling a pressure regulator is a specialist job. In any case they seldom ever give any trouble. If the regulator cycle time is now 3 minutes or more, there is no reason to suspect any problem with it, and even if it does have a bit of leakage that can usually be solved externally by reseating the non-return ball and bleed valve ball, as described elsewhere on this forum.

I would also recommend against dissassembling the anti-sink valves unless they are actually giving problems.

Regards,
Simon

[JohnCKL]

The black o-rings are all inside the main control block, not inside the solenoid. All the openings have O-rings. The solenoid filter end has 2 green O-rings. I meant that I can't find suitable replacements for those 2 green O-rings. Maybe should have approached a few parts suppliers. I was told the green O-rings have different properties than the black ones, so did not replace them.

'I notice in your close up picture of the solenoid you have the green o-rings removed. (At least they're green on mine)' Yes, I did removed them and placed them on the left of the picture. Have to put them back as I didn't take the trouble to shop for green O-rings. 'The large o-ring is the seal that prevents external leakage. Was this leaking on your original one ?' Not sure, the bottom part of the solenoid was not opened in my original electrovalve. Only accidently opened the top part in trying to remove it to facilitate easy removal of the top large pipe.

'Ok, so now the centre sphere is actually working, but it sounds like the centre sphere also needs gassing or replacing, it should move a lot more than 2cm if you sit on it.' Didn't sit on it, just pressing it down by hand and weight of body. I think if sit on it, it should go down 3-4cm.

'Stripping and cleaning a height corrector is no harder than the Hydractive unit, BUT getting the front height corrector out of a Xantia is EXTREMELY difficult due to the location. Unless you have a 4 post hoist I'd suggest not doing it unless really necessary, I was foolish enough to attempt it with only drive on ramps and it was an all day job to get it out and refit it, which involved considerable swearing and bruised knuckles. The actual cleaning didnt take long...' I'll take your advise.

'Also the symptom of the car popping up like a cork when going from full height to normal height dissapeared as I hoped it would.' Mine do sometimes, even twice after refitting the electrovalve.

'Unfortunately after going for a short test drive, the internal leak seems to have returned, although perhaps not as badly as before. There must still be some foreign particles caught in the solenoid which I'm unable to clear out, so it looks like I'll have to get a replacement solenoid for the front after all. Luckily the rear one seems to be fine.' Hope this doesn't happen to me.

'So which did you open accidentally ? The faulty one you removed, or the new one you were putting in ? Did it break it or was it just very tight, or did it have some kind of loctite on the threads ?' I accidently opened the faulty solenoid I was removing but unable to open the used one as it was just too tight.

'It looks like it should unscrew between the nuts at both ends, but I was unable to do it without applying more pressure than I thought safe, especially when I have no spare and no hope of getting one locally.' Yes, it should but the nuts are too thin for a good grip on the vice.

'Are the "parts which came out" the items in picture 1 ? If so, those are the damping valves And yes, the small hole side faces outwards as you show in your picture.' Yes, those are the damping valves with 2.6 stamped on them and the small hole faces outwards, then its correct in mine. The back are round protrusions.

'If the damping valves are not symetrical and you reverse them, it will swap the bounce and rebound damping characteristics - not a good thing to do, especially if only one was swapped by accident.' Reverse meaning upside down, then no, I didn't reverse them, I got them right side up. Both top and bottom damping valves are the same and interchangeable, right?

'Which o-rings do you think fixed the problems ? Are you sure it wasn't changing the solenoid that fixed it ? On my one at least, the source of the leakage is the seat of the needle valve where it exits the overflow pipe - in the ON mode the seat doesn't quite seal properly, and as far as I know no o-rings are involved there. Of course yours may have been leaking at the o-rings as well.' I thought the O-rings were leaking but you could be right, it could have been the solenoid. Yes, there are no O-rings in the solenoid itself. The external leak could be from the O-rings.

'Whoa there, don't get carried away' haha!

'I wouldn't go stripping down the pressure regulator, if you aren't familiar with whats inside it and havn't done one before you will get into BIG trouble.... there is a VERY BIG SPRING that can potentially seriously injure you if you attempt to dissasemble it incorrectly or without the necessary tools. DANGER!

Overhauling a pressure regulator is a specialist job. In any case they seldom ever give any trouble. If the regulator cycle time is now 3 minutes or more, there is no reason to suspect any problem with it, and even if it does have a bit of leakage that can usually be solved externally by reseating the non-return ball and bleed valve ball, as described elsewhere on this forum.

I would also recommend against dissassembling the anti-sink valves unless they are actually giving problems.'

Point taken, will consult with my mech on the pressure regulator which is leaking now due to the mech's apprentice, probably screwing on the bleed valve too tightly, its leaking from there. The HCs also seems intimidating, no 4 post hoist, doesn't seem to have any problems correcting height, so I'll leave those alone too.

The anti-sink valve maybe needs some attention. Whenever the car is switched off, the back sinks about 2-3cm after some time, is that a problem? What other symptoms of a problematic anti-sink valve?

[Rostami]

Very interesting topic. Thanks to John and Simon for their enlightening posts.

I just have one question: does Citroen sell an O-Ring kit for this operation? It would sound too good to be true if they would stock the kit.

Regards,