Mark 2 Xantia anti-sink

rmunns · Unread post by **rmunns** » 06 Jan 2010, 20:13

I noticed this evening that my year 2000 Xantia (saloon) is sitting 'high' on the suspension.

Today I fetched 4 bags of cement, in the boot. A couple of hours after arriving home I took these bags out of the boot.

It was after that that I noticed the car was well up on the suspension (both front and back).

So the question is, why, after arriving home with nothing in the boot and switching off and then both of us (150kg) getting out, does the car not rise? Should we wait 2 hours before getting out after switching off?

deian · Unread post by **deian** » 06 Jan 2010, 20:23

maybe you need a new anti-sink sphere, but the anti-sink sphere is nothing to do with anti sink, it just keep the pressure on a valve,

have you tried starting the car to see if the pressures equalise and the height corrected?

rmunns · Unread post by **rmunns** » 06 Jan 2010, 23:24

Thanks, Dei, but doesn't really answer query.

Citroenmad · Unread post by **Citroenmad** » 06 Jan 2010, 23:33

So you drove home with some cement, took that out and it rose up when you took the weight out, but when you came back later and two of you got out of the car it didnt rise up again?

If so that wont be your anti sink, as that just stops the car sinking when its parked.

Unread post by **CitroJim** » 07 Jan 2010, 06:05

What you are seeing here is (almost) normal. As heavy weights are removed from the car (either people or goods) the car will rise on its suspension and in the case of bags of cement, quite high too.

What should then happen after 30s, even with the engine stopped, is the height should correct itself downwards to normal ride height.

However, if there is no reserve of pressure to do this, because say, the accumulator sphere is flat, then as soon as the engine stops, pressure falls almost immediately and the anti-sink valves kick in and keeps the car on high.

Test you height correctors and accumulator sphere as follows:

Start up and allow things to normalise. Sit on the tailgate lip and feel the rear sink a little under your weight. Sit tight for 30s and the rear should rise to compensate and regain normal ride height. Get off the lip and the rear should rise high and then after 30s, fall back to normal. This proves the height correctors are working properly.

Repeat at the front.

Switch off engine. No quickly dash to the rear and sit on the tailgate lip and feel the rear sink. Wait 30s and the rear should rise back up to normal using the stored reserve of pressure in the accumulator sphere. If it does rise, get out and see the rear rise even further. There should be just sufficient reserve to drop it back to normal before the anti-sink valve comes into play. This is known as the "sit in the boot test".

If the "sit in the boot test" fails but the first tests with the engine running are good then it's an odds-on bet that the accumulator sphere is falt or you have a big internal leak in the system.

Is the car a Hydractive model?

Dei, this has little or nothing to do with the Anti-Sink sphere. 'Tis so mis-named. The Anti Sink sphere is a supplementary accumulator to supply a reserve of pressure to the rear brakes when the rear anti-sink valve is in operation and has isolated the rear corner spheres from the braking circuit; it is from the rear corner spheres that the rear brake pressure supply is normally provided.

rmunns · Unread post by **rmunns** » 07 Jan 2010, 06:59

Thanks, Jim, for that very comprehensive reply. When it gets fit again to be outside, then I'll try your tests.

The car is a 2000 90Hdi saloon, non-hydractive (I think, how do you know?).

Xaccers · Unread post by **Xaccers** » 07 Jan 2010, 09:07

LX and SX models are non-hydractive, anything above that spec is hydractive.
Pop the bonnet and check the size of the pipes going to the front struts, if they're big then you've got hydractive, if they're small, you've got non-hydractive.

DickieG · Unread post by **DickieG** » 07 Jan 2010, 10:32

If I'm reading this correctly, you get out of the car leaving a 4 bags of cement in the boot which you then remove two hours later after which the car sits high on its suspension and remains so.

If that's the case then its totally normal because between you getting out of the car and removing the cement, the anti-sink valves lock in and will remain locked until you start the engine which allows sufficient pressure to build up and open the anti-sink valves at which point the suspension height should return to normal.

Every Xantia I've owned with anti-sink has done this, the only change to this will be if the car is fitted with Hydractive suspension and you leave a door/boot open for a long time thereafter (30 mins) as that will open the Hydractive valves which allows hydraulic pressure to subside.

Your question of the car not doing the above when you get out just after stopping the engine is that the anti-sink valves are still open at that point and so allow the ride height to correct.

Everything totally normal to me.

rmunns · Unread post by **rmunns** » 07 Jan 2010, 11:31

Hi Zac. It's a forte model.

I did all the tests and I'm happy it is ok.

Thanks to all.

Xaccers · Unread post by **Xaccers** » 07 Jan 2010, 12:36

rmunns wrote:Hi Zac. It's a forte model.

I did all the tests and I'm happy it is ok.

Thanks to all.

Pretty sure Forté is the same as LX, so non-hydractive, but definitive test is to check the front strut pipes, 3.5mm and it's non, something like 6mm and it's hydractive.

Citroenmad · Unread post by **Citroenmad** » 07 Jan 2010, 13:00

No the Forte is not hydractive, no other 90bhp HDis are either. Only the Exclusive are hydractive, which is the only hydractive S2 xantia.

Xaccers · Unread post by **Xaccers** » 07 Jan 2010, 14:00

So there are no VSX S2s?
Pedantically, isn't the Activa also hydractive?

Citroenmad · Unread post by **Citroenmad** » 07 Jan 2010, 14:46

Yes how could i forget the Activa, though thats special and not a diesel

No there is not a VSX, that was replaced by the Exclusive trim level, which only came with the 110bhp HDi diesel, and obviously the petrols (2.0 16V, 3.0 V6) so no 90bhp xantia HDis have hydractive.

Exclusive is a very nice trim though, leather heated and electrically adjustable seats, headlamp washers, 6 disc cd changer, auto wipers, diesel preheater on HDis etc.

Unread post by **citroenxm** » 07 Jan 2010, 17:46

Xac wrote:So there are no VSX S2s?
Pedantically, isn't the Activa also hydractive?

Exclusive on S2 replaced VSX, although in S1 cars VSX ran just below Exclusive, though Exclusive was only on V6's...

so theres, Base, LX, SX and Exclusive trims.. LX on S2 cars is quite high..

ABS, front fog lights, electric passenger mirror, velour trim..

Paul

Citroenmad · Unread post by **Citroenmad** » 07 Jan 2010, 18:11

And also the S2 special editions, like the Forte - Based on LX, Stateside etc.

Aircon on LX S2 also.