Rolling issue

[MisterClaude]

Hello everyone,
It seems that my newly restored activa has a rolling issue after all.
The weird thing is that about half the time it is behaving like a proper activa.
But is the other half that is worrying me
Basically, when steering suddenly, the car just leans, and it leans more than a normal one.
We did the following to the activa system:
Replaced all spheres with the proper ones (mostly new) and charged to correct pressure.
Changed lhm
Bled the brakes
Refurbished the activa rods and Rams
Changed the pads with new
Changed the rear activa electrovalve
Checked the hydractive electrovalves, they are ok.
Lexia communicates and reads all the sensors and parameters, no errors.
However, it still leans.
What we are about to investigate:
We noticed that when starting the engine, it takes ages for the stop light to go off, however, if accelerating a bit, you hear a click in the front and the lights suddenly dim and close.
Besides checking for pressure loss in the middle disjunctor, are there any other things that your experience says I should check?
Also, it seems that at high speed it stays firm on the bends, but while driving in the city at slow speeds and steering fast, it rolls. If the curve is long enough, it corrects.
Thank you.

[Simple76]

Hydraulic pump sluggish possibly.

[GiveMeABreak]

I would not suspect the hydraulic pump immediately, as there should be reserve pressure in the front and rear accumulator spheres. However the fact that the STOP light is taking ages to go out suggests to me that the LHM filters are probably blocked. Although you have replaced the LHM fluid have you rinsed out and cleaned the system and cleaned the LHM filters? These can be completely blocked and of course, it doesn’t then matter how new the LHM is, if it can’t circulate properly it can affect all the systems.

The system can be flushed out with Hydraurinçage.

[Simple76]

Normally feel it in the steering first if filters are blocked. I would start by having pump and regulator tested.

[MisterClaude]

Hello,
First of all, thank you for the prompt reply.
The pump was replaced, but not with a new one, of course, it is possible for it to be a bit tired . I think we'll test the pressure whenever we have the chance..
Will inform the mechanic about the new suggestions.
By the way, how can you tell by the steering if filters are blocked? It seems to steer cursive, no hard spots as far as I can tell.
Edit: I have asked the mechanic. It seems that the filters were changed and the system cleaned.
Next thing on the list is to change the pressure regulator in the front of the car (the one by the rad).
If that fails, most likely we will try cleaning the hydraulic block in the back(the one that holds the activa electrovalve).
I will keep you informed on the new findings:)

[GiveMeABreak]

Ok, so here is the Filter component - incorporated into the LHM tank. There are documented cases where cleaning the system out especially the filters has cured rear sinking issues with electrovalves, so if you have eliminated other possibilities I strongly suggest you clean the filters out - there are surprisingly, a lot of Citroen 'specialists' that still don't know about the filters and the impact this can have on the system when blocked. Blocked filters can put a lot of strain on the system as the oil is trying to get back and forth and if you haven't done this in your ownership of the car, then you can't also guarantee that it has been done previously.

There's a guide on cleaning this out here, with photos, by Andrew:

Cleaning LHM Filter Guide

As for the roll control and firmness, here's how the valves work:

In the "firm" mode, valve ( 26) enables the vehicle roll to be avoided. It prevents the transfer of the LHM fluid between the 2 suspension units. When the vehicle is rolling, the fluid tends to pass from a suspension unit to the other; this causes the ball to move and block the passage; the suspension units are no longer interconnected. Height Correction In the "firm" state, valve ( 26) enables the height of the vehicle to be corrected. It allows the transfer of the LHM fluid from the height corrector to the suspension units.

"Fluid Admitted" Correction The height corrector is in the "fluid admitted" position. The supply pressure from the height corrector pushes the ball to the bottom of the valve. The suspension units are supplied by the corrector.

"Fluid Expelled" Correction The height corrector is in the "fluid expelled" position. The ball is released in the valve housing. The suspension units are linked with the hydraulic fluid reservoir.

[white exec]

For the system to be properly cleaned, it needs to run on Hydraurinçage (in place of LHM) for around 3000-5000km. A quick clean as part of rebuild/service will not be sufficient. 1 x 5L of H. will do; just empty the reservoir (syringe or syphon) and refill.

Also, was the hydraulic system thoroughly bled after the last work done on it? I think on Xantia this needs to be done at the four brake bleed calipers. If incorrect, for Activa, someone here will put me right!

[MisterClaude]

First of all, thank you for the detailed explanation. I'm sure it took some time for digging. It really helps me understand the system.
I have asked the mechanic (which is a friend of mine, owning a citroen independent service, which also owns an activa ) and he confirmed that the LHM tank was took out and cleaned. Also the filters. Indeed, no solution was used (neither Hydraurinçage nor other), so we might try this if anything else fails.
The car doesn't have any sinking issues. It's just the anti-rolling that sometimes fails. We will change the pressure regulator and the brake distributor/regulator next week (which is making a whoosing sound when pressing the pedal) and fingers crossed, we hope it will improve. If not, next spring we will try Hydraurinçage, because winter is coming and I'm not going to do 5000 more km this year.
Thank you again for your patience and I will keep you posted next week, on the results after changing the regulators.

[white exec]

Dirt clinging to the interior of the reservoir isn't too much of a problem, it's the dirt in the rest of the system (valves, seals, control mechanisms...) that can cause problems. H'cage is extremely good at removing this, and the car can be run on it for a very long time. There would be no problem in using it now, and leaving it to do its work over the winter.

When it is to be taken out (and the car returned to normal LHM), just empty the reservoir, refill it with LHM, and bleed at the four brake calipers until clean, green LHM comes through. It doesn't matter if a small quantity of H'cage remains in the system - it is completely compatible withh LHM.

There is a recommended technique for bleeding (which I think applies to both XM and Xantia), and an order in which the bleed screws should be opened.

Someone here will be able to confirm the details for Activa.

[MisterClaude]

Hi,
I've searched Hydraurinçage on Google and it seems that unfortunately it cannot be found in Romania. I have found it on ebay, on a french website and on an italian website, but I assume the shipping costs for 5kg will be more than the price of the product itself I will keep asking here and there, maybe some spare parts dealer will be able to find it.
Speaking of finding parts.. it's really hard for me to find any specific NEW activa parts here in Romania. While it's a breeze to order the standard parts (alternators, cambelts, clutch parts, and so on) when it comes to the activa bits, it's total silence.
Can you guys still find activa/hydractive electrovalves, rods, rams, etc.. in UK? New, of course?
Thank you.

[GiveMeABreak]

Parts as always are getting more harder to source as time goes on - but if you look in the For Sale / Wanted Section, there are a few Activas up for sale:

It might be worth a trip over to bring one back!

viewtopic.php?f=7&t=60919

[white exec]

Hydraurinçage is still in production by Total, in France.
Some individual countries no longer keep it on their Total shelves, or even list it*, but it is still available to Citroen dealers (parts) who want to order it. You are unlikely to find it elsewhere, eg at outlets who stock Total motor oils.
There won't be much demand for it, and so some Citroen dealers won't recognise it, or will claim never to have seen it.
Remind them it's actually made by the same people who make LHM Plus, Total.

Couple of pictures here of what it looks like, which might help convince your Citroen dealer:

EDIT: Citroen part number is 11350 01 Hydraulic suspension/steering fluid (cleaning), 5-litre
Price can be similar to LHM Plus, or up to twice the price. Good news is that you'll only need 5L.

In some places, it has been packaged in plain orange containers. This may have been temporary bulk packaging from a while back.

______________________

* The UK now does, having re-instated it to UK stock listing at our request.

[Simple76]

Normally find if the filters are blocked the steering suffers first as it requires more of a constant pressure. It seems like you either have some internal leak or supply pressure fault. This is why I suggested having your pump and regulator checked first. There are certain places in the uk which if you send them the parts they will test for you. Thus not having to replace parts.

[MisterClaude]

Hi,
In about a week a friend will come with a pressure gauge, made specially for testing the xantia piping.
I think we can find another pressure regulator if needed (of course, used). Maybe even a pump.
Also I have askee this friend, old-time XM and BX owner, he said that last time he was able to find hydraurincage was in 2010 )
And by the way, thank you for the For Sale suggestion. Will definitely have a look.

[Simple76]

Alternatives to hydraurincage heard of hydra flush.