Xantia sinking problems

martinp · Post by **martinp** » 13 Apr 2004, 03:12

Hi, my 1998 Xantia 2.0i VSX turbo estate (Hydractive 2 with 8 spheres) is having a few problems that I hope someone may be able to help me with. I've searched the forum, but can't seem to find anyone who has had the same combination of problems as me.
Firstly, when the engine is stopped, the rear of the car drops rapidly. Not knowing any better at the time, I changed the anti-sink sphere, which of course made no difference.
Secondly, about a minute after the engine has been started and the rear has risen to it's normal height, the rear suddenly drops before eventually rising again after 10-20 seconds. This happens whether the car is moving or not.
Thirdly, when I take my foot off the brake after stopping at lights etc, the rear suspension again drops down.
Are these faults in any way connected, or have I got several separate snags? I understand from various threads that it could be the anti-sink valve, accumulator sphere or the brake doseur valve, or even all three. The car has done about 50K miles incidentally. Any pointers anyone? Any help would be greatly appreciated.

AndersDK · Post by **AndersDK** » 13 Apr 2004, 04:21

Your Xantia is approx 6y's old with 50Kmiles on the wheels.
That's approx the average time the spheres will last, and you begin to see all kinds of problems.
A pointer :
Have engine running idle.
Deliberately set the suspension height to lowest height possible, wait untill you feel the car settles on rubber stops.
Now open the bonnet and time the ticking interval from the hydraulics pressure regulator. Simply use your wraist-watch, you just need to get it accurate within 5-10 seconds.
The idea is that all suspension circuits are disconnected in lowest setting. Hence no (internal, or bypass) leaks from here can disturb the central hydraulic system.
The ticking interval should be at least 1 - 1.5 minutes.
Shorter time intervals means a no-go test : you need a new main accumulator, which is the sphere located on the engine block.
If you can not seem to reckon a ticking, but rather have a constant rattling, then it's certainly a no-go indication.
It's known beyond any doubts, that a (nearly) flat main accumulator sphere causes all sorts of strange symptoms to the HA type suspension.

jeremy · Post by **jeremy** » 13 Apr 2004, 04:27

Have you tested the accumulator sphere? If you sit in the boot of the car with the engine running it should drop about 4 inches, then rise after about 20 secs, rise again when you get out and then drop after 20 secs. You should now be able to repeat the exercise with the engine off (but ignition on to keep the anti-sink valve open.) The car should do the cycle at least once and someone has suggested twice is normal.
Replacement is not particularily difficult and a good accumulator is essential for the proper functioning of the system.
jeremy

alexx · Post by **alexx** » 13 Apr 2004, 12:00

Hm. This could be connected with hydractive system. Try this - temporarily pull out a fuse leading to hydractive computer and take a short drive. The car will stay in hard mode, so ride won't be very comfortable, but you'll see if the problem is absent at that state.

martinp · Post by **martinp** » 17 Apr 2004, 00:10

Thanks for all the advice guys, I plan to change all the rear spheres this weekend anyway as the rear suspension feels very hard, especially when towing. I'll check the other things out at the same time and let you know how I get on. Thanks again

martinp · Post by **martinp** » 17 Apr 2004, 00:39

Looks like I need a new accumulator sphere, the ticking interval is approx 20 seconds when the car is at it's lowest setting. The car also fails to drop (or rise) when I follow Jeremy's suggestion with the engine is stopped with the ignition on. Incidentally, the car's actually done 60K miles, not 50K as I said earlier. I haven't tried the fuse pulling exercise yet alexx, but I certainly will if the problems continue.

Post by **philhoward** » 17 Apr 2004, 00:45

There won't be any "drop and rise" with the engine off, due to the Anti-sink

martinp · Post by **martinp** » 17 Apr 2004, 01:12

Even with the ignition on, as Jeremy suggested?

Dave Burns · Post by **Dave Burns** » 17 Apr 2004, 01:19

Anti sink valves are opened by hydraulic pressure, not by electrical means.
Dave

martinp · Post by **martinp** » 17 Apr 2004, 01:22

Ah, I understand. Thanks Dave.

jeremy · Post by **jeremy** » 17 Apr 2004, 12:00

Thanks Dave - I'll remember that.
Jeremy

martinp · Post by **martinp** » 19 Apr 2004, 00:12

I changed the accumulator and the 3 rear suspension spheres yesterday. Seems to have done the trick. No more dropping rear end and it feels like a totally different car. Thanks everyone.

NiSk · Post by **NiSk** » 19 Apr 2004, 00:31

Well , all you have to do now is change the front spheres and you'll be in heaven! (they take twice the weight compared with the rear spheres!)
//Nisk