Workaround for bubbles in LHM return flow

[white exec]

I think you were saying that the rear suspension could "bottom out" under hard acceleration, and hit the bump stops.
Two things should stop this happening (apart from the rear spheres):
1 - Rapid or significant use of the accelerator pedal should push the system into Firm, to prevent rear-end squat and stabilise the car;
2 - Rapid vertical movement of the body should do the same - flip the system immediately into Firm.
The tell-tale LEDs should show whether the two sensors (accelerator pedal, body movement) are working properly.

Both these things should cause the car run solely on the corner spheres, which only allow minimal body movement. This minimal 'Firm mode' movement can easily be felt by pushing down on FF or RR of the car after the engine has been switched off, and the EVs have turned off 30secs later . . . i.e. a bounce test of Firm. The amount of downward movement should only be a couple of cm at the front, and less than 5cm at the rear. If it's much softer, Firm mode is not operating properly, and the corner spheres would need looking at.

Ride height checks...

[MatPL]

I think you were saying that the rear suspension could "bottom out" under hard acceleration, and hit the bump stops.
Two things should stop this happening (apart from the rear spheres):
1 - Rapid or significant use of the accelerator pedal should push the system into Firm, to prevent rear-end squat
2 - Rapid vertical movement of the body should do the same - flip the system immediately into Firm.
The tell-tale LEDs should show whether the two sensors (accelerator pedal, body movement) are working properly.

1. The acceleration function works and hardens the suspension strongly, but only for about 2-3 seconds after the acceleration is pressed suddenly. After about 2-3 seconds, it returns to soft, especially in gears 3 and 4, where the accelerator pedal is still pressed. In a gasoline engine, I often accelerate for more than 3 seconds and then it goes low. In sport mode, the hardness reacts much faster and lasts longer as described by Citroen.
2. Rapid movement works fine but it doesn't work when accelerating because it's mounted at the front, and when accelerating it changes the height of the rear axle.

I recorded a quick gentle start. 1st move switched to sport mode. Soft all the time later.


The second recording is the reaction of the HA computer to the accelerator pedal and the movement of the steering wheel in soft and sport modes.


In my opinion, the electric control of the suspension works perfectly for its age. Hasn't reported any errors for over 3 years. It undergoes 30-second static tests each time. I tested the HA suspensions on 3 computers and they have the same effects.
Thank you for the documentation. I just don't understand why on the higher 195/70 tires the suspension should be set lower than on the lower profile 205/60 tires.

[white exec]

Mat,

B7 Training Manual
Not sure whether you have this Citroen document, which contains a lot of useful information.
It can be downloaded here, for example...
http://www.ckc.dk/pubs/technical-traini ... -62304.pdf

See Section D: Accelerator pedal travel sensor
and also printed page 54
and page 57, which specifically talks about continued acceleration and how Firm mode would be maintained during it.

Re: that last pull-away-from-rest video, remember that at very low speeds Firm mode will not operate (even if Sport is selected), so any pull-away from standstill will always be in Soft mode.

Lots of diagnostic info in the document, too.
Hope helpful.

[MatPL]

The firm mode works only above 24 km / h, but if I stop without turning off the engine and quickly press the gas pedal, the firm mode will also work when parked. I do not know why. In the manual it is written that below the speed of 24kmh is soft mode permanently.
Thank you for the documentation.
For the last 2 days, when the temperature outside is below 0, I noticed that the car was driving better and better. The morning stop light goes out for 4 seconds after starting the engine.

[lcwin]

Hi MatPL , you can remove the 6 piston and spring in the hydraulic pump that drives the steering n c . This isolate the steering circuit. I am not 100% sure as I don,t hv the pumps anymore but check with a technical guy to confirm. Or you can start with removing the 2 piston for the Suspension circuit which is much easier to test and then go to the steering circuit if it is not the culprit.
Your testing of the funny bouncing etc is just due to the effect of air bubbles in the suspension. Nothing out of the ordinary. Air in high pressure hydraulic circuit acts like a variable sphere depending on situations.
Lastly when you used the clear hose to test did you let the car rest at its lowest level for a day before testing?

[ksanturion10]

Ride height checks...

Nice info you are putting out here Chris .
I know the thread jumped from bubbles into the suspension to height calibration, which is understandable,
but I was wondering if you have something similar for post 1997 X1 Xantia.
What I found so far is:
1. This pic for pre 1996 Xantia (found on the Net, don't know if the values are true ):

2. This page from the Forum's "S2 Xantia.pdf" link/file, where I found something strange:

Onto page 214 there is no table in regard to the height adjustment?
It could be something onto my comp only, just puzzled, that's all.

drBR
Martin

[white exec]

Hi Martin,
I will take a look at the booklets I have on file.
These mechanics' bookkets were continually re-edited over a good few years, and some of the info/references in them didn't get properly overhauled. The page reference number might be one of these errors.
If you need the info for your Xantia, what year is the car?
VIN number if you can, too.

[ksanturion10]

Hi Chris, thanks for taking time, but please, it's not urgent at all, and don't bother if it is going to be too much effort.
I'm just trying to reassure myself, that I can use the method provided by the "S2 Xantia.pdf" file. Ofcource mine is S1 Xantia, and maybe that method is not relevant.
There is written, for the front H1= R1 - L1, where L1=121 mm; and for the rear H2= R2 + L2, where L2= 136 mm. L1 and L2 are such at "Normal height" I guess.
I'm using 185/65/R15 tyres, so 15*25,4= 381 mm, and 2R1(R2) = 381 + 2x65 = 511 mm, so R1(R2)=~245 mm with the flattening of the tyres.
So, H1= 245 - 121 = 124 mm, and H2= 245 + 136 = 381 mm.
Pretty different from H1= 155 mm and H2= 420 mm, despite only tyres ~490 mm in diameter are cited into my first pic for pre 1996 Xantia. Calculating the above with 490 mm diameter will give even smaller H1= 114 mm and H2= 370 mm.
Now, while digging deeper into the matter, it seems to me, that that type of data and/or method for calculation are pretty specific for every different range produced, and maybe non of the two sources I'm citing are really relevant to my case. As you said, many changes were made during the production phase, and probably they've involved also the geometry of the ride height, which is pukka
The car is 1997, January I think, but this is only, what I can disclose for the moment being.
As I said, don't bother if it is going to be too much effort, I think I'm closing on it tbh

drBR
Martin

[MatPL]

Hi MatPL , you can remove the 6 piston and spring in the hydraulic pump that drives the steering n c . This isolate the steering circuit. I am not 100% sure as I don,t hv the pumps anymore but check with a technical guy to confirm. Or you can start with removing the 2 piston for the Suspension circuit which is much easier to test and then go to the steering circuit if it is not the culprit.
Your testing of the funny bouncing etc is just due to the effect of air bubbles in the suspension. Nothing out of the ordinary. Air in high pressure hydraulic circuit acts like a variable sphere depending on situations.
Lastly when you used the clear hose to test did you let the car rest at its lowest level for a day before testing?

What is the purpose of removing the plunger? It's about checking if the air is in section 2 or 6? Unfortunately, microbubbles are everywhere. They appear in the tank about 3 seconds after the engine is started, from where the pump immediately begins to draw the liquid with micro-bubbles and spreads throughout the entire system. In the morning, the car drives very nicely for about 1 minute (time to leave the parking lot and then a straight uneven road - the suspension is selected smoothly and quietly for about a minute). I installed about 5 used pumps (each with new seals). Recently I bought a new CItroen pump to finally exclude something from the system. The problem with the air is still there, so I don't think it's the problem of the pump or the hose feeding the pump, I had a lot of them with different diameters and hardness. I have been riding a transparent hose for over a month. The suspension was down and it rested for over 24 hours. In addition, when venting, I always do so that the power steering only works first and I start the engine for about 10 seconds and turn it off. I wait for the oil to release air in the tank. I repeat until the oil is almost clear of air. Then I turn 12 on the conjector. Suspension goes up and I quench the engine lowering the suspension. I wait for the air to escape from the reservoir and repeat this twice. This week, maybe I can rebuild the power steering return hose, I will let you know if something has changed.

Hi Chris, thanks for taking time, but please, it's not urgent at all, and don't bother if it is going to be too much effort.
I'm just trying to reassure myself, that I can use the method provided by the "S2 Xantia.pdf" file. Ofcource mine is S1 Xantia, and maybe that method is not relevant.
There is written, for the front H1= R1 - L1, where L1=121 mm; and for the rear H2= R2 + L2, where L2= 136 mm. L1 and L2 are such at "Normal height" I guess.
I'm using 185/65/R15 tyres, so 15*25,4= 381 mm, and 2R1(R2) = 381 + 2x65 = 511 mm, so R1(R2)=~245 mm with the flattening of the tyres.
So, H1= 245 - 121 = 124 mm, and H2= 245 + 136 = 381 mm.
Pretty different from H1= 155 mm and H2= 420 mm, despite only tyres ~490 mm in diameter are cited into my first pic for pre 1996 Xantia. Calculating the above with 490 mm diameter will give even smaller H1= 114 mm and H2= 370 mm.
Now, while digging deeper into the matter, it seems to me, that that type of data and/or method for calculation are pretty specific for every different range produced, and maybe non of the two sources I'm citing are really relevant to my case. As you said, many changes were made during the production phase, and probably they've involved also the geometry of the ride height, which is pukka
The car is 1997, January I think, but this is only, what I can disclose for the moment being.
As I said, don't bother if it is going to be too much effort, I think I'm closing on it tbh

drBR
Martin

I have a description of the height of the Xantia but depending on the engine, not the size of the tires. Maybe it will be useful to you.

[ksanturion10]

Yes, thanks .
I was thinking, that it should be related somehow to the axis of the final drive at "Normal height", and not so much onto the tyres

Pfff, I have some faint memories before Christmass, I did an "overhaul" of my pump, it was leaking from the suction pipe at the pump itself -> cutted the old hardened piece of it and fitted new pipe (for mineral oil, NBR), but with better/larger "R" before going into the pump's shtutzer. Couldn't unscrew non of the 6 pistons, the torx started distorting and I left them how they were. Only changed the O-rings onto the 2 piston side, Vitons are the last I've putted there - and did something, that you maybe didn't already, made a new paper gasket for the output cup . Special paper for gaskets... aaa, and also the front and rear O-rings, 36x2,5 and 44,2x3 or something, NBRs I putted there. Actually the 36x2,5 is not very correct, but it does the job . Also left the front shaft seal, it was OK.
And if memory is OK, I think I was seeing bubles into the tank before this overhaul, and non after it... have to check again.
But my problem is more from wrong calibration of the heights, than from the bubblin'

Can you share the whole .pdf

[MatPL]

Yes, thanks .
I was thinking, that it should be related somehow to the axis of the final drive at "Normal height", and not so much onto the tyres

Pfff, I have some faint memories before Christmass, I did an "overhaul" of my pump, it was leaking from the suction pipe at the pump itself -> cutted the old hardened piece of it and fitted new pipe (for mineral oil, NBR), but with better/larger "R" before going into the pump's shtutzer. Couldn't unscrew non of the 6 pistons, the torx started distorting and I left them how they were. Only changed the O-rings onto the 2 piston side, Vitons are the last I've putted there - and did something, that you maybe didn't already, made a new paper gasket for the output cup . Special paper for gaskets... aaa, and also the front and rear O-rings, 36x2,5 and 44,2x3 or something, NBRs I putted there. Actually the 36x2,5 is not very correct, but it does the job . Also left the front shaft seal, it was OK.
And if memory is OK, I think I was seeing bubles into the tank before this overhaul, and non after it... have to check again.
But my problem is more from wrong calibration of the heights, than from the bubblin'

Can you share the whole .pdf

I don't know how to share the pdf on this topic.
Little when it leaks from the 6 piston section. A common problem is with the 2 sections of the suspension and NBR seals. Alternatively, use NBR 90shA, it deforms less and lasts longer. I mainly use Viton / Fluor, unless the size is not appropriate then NBR90. I have a paper seal in the original. The simmering on the shaft had to be replaced as you had everything pulled out and put it a little closer than it was to let it work itself on the clean surface of the shaft. I used Viton brown as it was originally.

[white exec]

Unfortunately, not possible to post pdf's into forum posts, or PMs.
If not too many pages, you can convert the pdf pages to jpg's (eg with Foxit Phantom) and post those.

Alternatively, send the pdf as an email attachment to the member involved.

[ksanturion10]

I don't know how to share the pdf on this topic.

Me neither , maybe with a PM , not sure.

Little when it leaks from the 6 piston section.

Not really sure what you mean by this? Mine doesn't make a drop right now, from nowhere . If you mean, that it leaks a little bit, it shouldn't.
Something else I can recall now, on the 2 piston section, on one of the two, don't remember which exactly, the ball was seizing into its washer cup, don't know if you checked for this also .
Onto the 2 piston section, at first I've putted new NBRs, but when it came to this "overhaul", they were somehow rotten, and decided to fit Vitons there. NBRs have better lower temperature limit, -35 deg C, Viton is only -15 deg C, but has better resealiance to different chemicals

[MatPL]

Little when it leaks from the 6 piston section.
Not really sure what you mean by this? Mine doesn't make a drop right now, from nowhere . If you mean, that it leaks a little bit, it shouldn't.
Something else I can recall now, on the 2 piston section, on one of the two, don't remember which exactly, the ball was seizing into its washer cup, don't know if you checked for this also .
Onto the 2 piston section, at first I've putted new NBRs, but when it came to this "overhaul", they were somehow rotten, and decided to fit Vitons there. NBRs have better lower temperature limit, -35 deg C, Viton is only -15 deg C, but has better resealiance to different chemicals

My point was that the 2 piston section is leaking much more often than the 6 piston section Of course, it has to be dry. That Polish description has over 160 pages and there is a lot of interesting information about the work and functioning of the suspension. I found something else for you

[ksanturion10]

Um, thanks for the effort
If you decide to share the polish version, just PM me