Removing 2.0 TCT engine and other Activa thingies

[xantos]

Just a few questions for the experts...

Is it possible to re-gas the spheres with +10 to +15 bar of designated pressure without damaging the membrane? I have spheres on the rear struts designated to 30 bar and would like to fill them to 45 bar as CitroJim suggests that it makes a more comfortable ride with estate spheres on the rear. So do they have the same membrane or is it different regarding to its pressure?

I also read that for better comfort on hydractive cars you put centre spheres that have more pressure than designated. Comfort is better, but when you need handling, the centre sphere is shut out and so you don't lose any handling. Quite logical I would say.

[CitroJim]

There should be no problem in going a bit higher Xantos. The maximum any sphere goes to in production is 72 bar and there must be a bit of room for safety! I'd not go beyond 80 bar if I was you...

You have the Technosir kit now so experiment!

You may find some benefit by going to 450cc or 500cc spheres for the centre hydractive spheres. They are bigger but should still fit although it might be a bit tight.

[Mandrake]

Standard Front OEM Hydractive spheres are 450cc at 75 bar or 500cc at 70 bar. Both were available from the factory for earlier models as shown in this list:

http://homepages.igrin.co.nz/simon/imag ... heres3.jpg" onclick="window.open(this.href);return false;

For some reason the 500cc version was dropped for later Xantia's, also 400cc was never used for that sphere at least OEM. If a 400cc sphere was used it would need to be 80 bars just to achieve the same ride softness but would run out of travel when the car was heavily laden, so the larger cc is definitely to be preferred. (Also a proper front Hydractive sphere has a much larger flow hole in the neck than all other spheres)

IMO a larger volume sphere is a better way to make the ride softer than increasing the pressure, so if you can get your hands on a 500cc front Hydractive sphere Xantos, that would be the way to go. (For the same pressure the larger volume will give a softer ride, so you can get a softer ride without going too high in pressure)

[xantos]

Thank you for your suggestions. Really appreciate it!

Now to get my hands on them 500cc spheres! But I'm not optimistic to get them though...

[xantos]

Anyone knows if you can get this part (marked red)? It's the return collar from servo cylinder, just like one for activa cylinder repair, but it's different in diameter.

[xantos]

Found it (http://www.frenchcarforum.co.uk/forum/v ... hp?t=33056" onclick="window.open(this.href);return false;).

Part number: 95 640 212, cost: 9,66 eur.
Jolly nice.

Edit:
I just remembered! When I had the engine out I tried to change the collar with a spare that I have for activa ram repair (same part number), but it was to small... Me thinks. If it fits I think it's time to get me coat

[CitroJim]

That's the XM one. It's identical (as far as I can tell) to the Xantia one but never listed. Odd

As you say, the one used for ram repairs...

[xantos]

Well I finally managed to fit tecnosir valves to my spheres. First I tested each sphere to see if they have enough pressure and the fitted the valves. Surprisingly none of the spheres was ruptured as I was sure that the front hydractive sphere is dead. Just the anti-sink and front sc.car were a little low (-20bar). I also had spare spheres that I salvaged from the hydractive Xantia that went to bits and also bought a set of 8 spheres for 50eur from a friend of mine. They were in unknown condition, but when I tested them all but one were ok. They are new series (grey) and have three dimples on (multilayer membran if I'm not mistaken). As I had 2 pairs of front wheels spheres with multi-layer membrane, I decide to put one pair on the back wheels. I believe they are the same, as the valve and the hole looked the same to me...

Also adjusted the height. Front was high about 3cm and back was low about 2,5cm.

To get to the pressurisation of spheres. I over pressured this much (maybe I exaggerated a little bit too much):
standard pressure/my pressure
- front wheels: 45bar / 55bar
- accumulator: 62bar / 62bar
- front hydractive 70bar / 80bar
- front sc.car (activa) 62bar / 70bar
- rear wheels 30bar / 50bar
- rear hydractiva 55bar / 70bar
- rear sc.car (activa) 30bar / 40bar
- anti-sink 50bar / 60bar

I expected that the car would be really soft and floaty but it isn't... It's better but still not as it should be (or maybe I'm asking too much ) Now when I drive over a big hole front cylinders get squeezed to max. and BANG! it feels like the strut will jump trough the bonnet... It happened before also, but now it's more frequent. Maybe the cylinder o-rings on the piston are worn... Also noticed that when I put the car on lift (without de-pressurising) and when starting the car with wheels of the ground I can hear a bang and wheels twitch. Like pressure is suddenly released.

I also played with return pipes that go into LHM reservoir, to try and figure out where I have an internal leak... This is how it looks:


It's pouring out of the two pipes that come from the brake doseur. I changed the o-rings in the doseur about a year ago and I don't think I made something wrong. Maybe the doseur is too worn... Also the front and back electrovalves are leaking in soft mode (only when engine off), although I stretched the springs in the valves:


And the main return pipe (the one that comes from high pressure regulator) is leaking heavily also... I would say that about a litre per hour (engine off of course). I made quite a mess as I forgot how much it leaks and didn't put it in a bottle to leak in peace Regulator clicks one time per 2 minutes...

And finally I found where it's leaking LHM. Not much, just a drop here and then. I needed half a year to find it! It's the high pressure regulator that is leaking where it's bolted to the engine mount. And LHM slowly creeping down the engine to the sump and then all the way to the back of the sump where it accumulates to a drop. Is there an o-ring that's leaking?

Quite a jolly nice challenge it's turning out to be, getting the activa soft

PS: Average consumption of LPG is 13 litres per 100km (21,5mpg)

[CitroJim]

Getting an Activa riding nicely is a good challenge. Mine is not bad at all now. Yiu will get there

Good work on the spheres

I don't understand why it should be so crashy over potholes and you're experiencing the front suspension bottoming out. Are you sure the corner spheres are of the right specification? If they are non-hydractive ones that may cause it.

Dosuer valves do leak a bit and in the old sinker cars was the main reason the rear would often sink much faster than the front. I don't think that's the cause.

The electrovalves are not good though. I've known them leak in soft mode despite spring stretching and cleaning. I've often thought about trying to refurbish the valve seats by trying to lap them in using very fine valve grinding paste.

The bang and the twitch mystifies me too unless it's the anti-sink valve opening. It may be that you have low main line pressure and that could account for may of your issues. Have you tried a pressure gauge on the output of the regulator to check the pressure. It should be 170bar and falling to 145 bar before the regulator cuts in to restore it to 170bar. These pressure are critical on an Activa.

[xantos]

So you don't think the cause for crashy ride is over pressure in the spheres? Well I believe I have the correct spheres as they were taken of a hydractive Xantia which suspension worked fine...
Here is a pic (not mine, but it's the same):


I don't have a pressure gauge, so that's the next thing I must fabricate... Makes sense that if there's not enough pressure in the system cylinders in the suspension bottom out. Is a faulty high pressure regulator a common fault?

[Hell Razor5543]

I have just looked on the AEP Direct website, and it would appear that the Activa uses different spheres for the struts than Hydractive or basic Xantias.

http://www.aepdirect.com/citroen-xantia ... ory_id=121" onclick="window.open(this.href);return false;

[xantos]

Right! I have just checked citroen.service and they don't have the same factory number... As I said I also put front strut hydractive spheres to rear wheels. But it looks like they are working ok at the back...

[Hell Razor5543]

I would wait for an Activa expert to update you re. the spheres. I bought 6 spheres off AEP recently, and they asked for my car details to make sure I got the correct spheres.

I just looked in my Citroen manual, and the Activa does use different spheres. The front strut spheres are part number 434510, the rigidity regulator sphere is 395010, and the suspension rigidity regulator is 435501. Other spheres appear to be common, either to hydractive or normal Xantias. Still, I would wait for somebody who knows the Activa inside and out.

[xantos]

Let's wait till 4.21am for Jim to wake up...

[CitroJim]

Still, I would wait for somebody who knows the Activa inside and out.

We could be waiting a long time James

On my Activa I use standard Xantia Hydractive Spheres on the from corners and Hydractive Xantia Estate Spheres on the Rear Corners...

It works nicely for me...