Nightmare Xantia Rear Suspension....

barneysvage · Post by **barneysvage** » 28 Feb 2005, 05:07

Guys...
I have spent hours this weekend replacing the rear spheres on my 94 SX TD.
I was replacing them cause the ride was 'orible' on the offside rear.
I had also noticed that on start up from cold, the rear would drop to the bump stops until I got 100yrds down the road.
I got the haynes manual, did all the necsessary with releasing pressures. Broke two good quality strap wrenches, & borrowed a BIG chain wrench from a neibour. finally got all three off, straightened out the subframes around rear hyd units & fitted new units from GSF.
Started it up, bled it, finally got it to go up (with much coaxing & jacking up & down), went to max & stayed there and wouldnt go down. switched it off, I went for a brew, came back started it up again, it went down to min and has not moved under its own steam since.
I have tried allsorts, even got a s/hand height corrector from a friend, made no difference. (all linkages are presant & correct, and the valve appears to move with the linkage). Even re-fitted old middle sphere..to no avail.
There is fliud pressure to one port on the height corrector but nothing elsewhere.
I can only assume I have got some crud in there somewhere and its got into what I think is the anti-sink valve which is now stuck in a no pressure position, there will be no pressure in the middle sphere so no rear suspension....
I havnt tried hitting it as yet, It went dark and I was cold and hungry.
The LHM looks clean & green, but I have not checked the filters yet, I have only had the car about 2 months, but it has a full service history mainly dealership. I checked the fluid levels as soon as I got the car, all was ok and it has never lost any since. I cant check the level cause the rear wont go up, but there is plenty in there if it does move...!
Any info will be greatly apprecicated as I am back on the push iron till it is mobile again...
Cheers
Jon

Kowalski · Post by **Kowalski** » 28 Feb 2005, 14:54

Did you top up the LHM after changing the spheres?
Does the stop light on the dash go out?

jeremy · Post by **jeremy** » 28 Feb 2005, 15:56

I think I agree with you. Strangely Anti Sink valves seem generally reliable.
have a look at this wonderful explanation of the workings of the whole car - Anti sink is on P 32
http://citroen2.triger.com.pl/kc/pdf/citguide.pdf
may be it would free with the appropriate application of brute force - or the valve would benefit from removal and if nothing else soaking in petrol.
jeremy

Richard Gallagher · Post by **Richard Gallagher** » 28 Feb 2005, 16:10

How far did you unscrew the 12mm bolt on the pressure regulator? Hopefully no more than one turn because you may have dislodged the small ball bearing within it. If so it may be worth giving the bolthead a gentle tap to get it to reseat correctly. You have re-tightened the bolt?
I take it you have checked that the little plastic link is still attached to the height corrector?
When the system has been depressurised it can take some time for pressure to build up again on systems with anti-sink, due to the lower volumes sent out from the twin outlet pump compared with earlier single outlet pumps.

RDD · Post by **RDD** » 28 Feb 2005, 18:23

All 4 of my suspension spheres were corroded on......strap and chain wrenches broke and bent on them. I ended up drilling a 12mm hole into them, inserting a very long bar and pulling......I share your pain

FrenchLeave · Post by **FrenchLeave** » 28 Feb 2005, 18:46

Is the misbehaviour at both front and rear or just the rear?

barneysvage · Post by **barneysvage** » 01 Mar 2005, 02:15

Cheers guys...plenty to go at there.
to answer some of your questions..... the warning lamp used to take a couple of seconds to go out until now... it goes out almost imediately on start up.
all the linkages including the plastic link is all attached and is operating.
The front end operates as normal, as does the pwr stg and the brake pedal feels as normal.
the first (& only) time I got the suspension to max high I had to top up the LHM res with a little less than a half a litre.
The 12mm de-pressurising bolt was only turned around half a turn as this was all it needed to release the pressure.
Jeremy...the schematic drawings are great.. but now I am even more confused...! If the anti- sink valve was stuck closed, it looks like it would not allow pressure to the height corrector, but I have fluid pressure at one of the ports on the hc, unless it would still bleed past / through the valve as this side of it is to open / close the other side.....????????.
I have tried the blunt heavy instrument thing this evening...with no success. I am in traford park tommorow morning so I am gonna get an anti-sink valve from GSF, I have already checked...they keep em in stock....! will try & fit tommorow pm & see what happens...
Cheers
Jon

FrenchLeave · Post by **FrenchLeave** » 01 Mar 2005, 18:20

I believe the Xantia circuit is the same as the XM. In that case the anti sink valve is fitted between the height corrector and the centre hydractive valve block so pressure to the height corrector will not be affected by the anti sink valve. However, I doubt that the a/s valve is the culprit. Your problem sounds similar to the problem I had recently on my XM. (Back end sinking to its bump stops within 20 seconds of switching off, Sticking on left hand side when pumping up and then freeing with a jerk. Rough riding at rear, etc). I too suspected the a/s valve but it turned out to be a massive leak internally on the rear suspension cylinder with a jamming ram. Try checking the return lines at the reservoir to see if there is a continuous flow of fluid. If there is you should be able to find out from where it comes.

barneysvage · Post by **barneysvage** » 05 Mar 2005, 23:37

Guys,
Finally fitted the anti-sink valve today....still not a whisper out of the rear end......
Losened every pipe at the back and started it up, fully expecting to get a green shower, nope....no pressure any where....?????. tightened em all up, Went to the front loosened one of the two presure outlets at the pump, nice steady flow. Went to the other (front of the pump) loosened it...nothing...loosened it a bit more....froth...then a steady flow of fluid. Hey presto the back went up. Bit of citroebics and alls well....!!!!!.
I can only assume that the pump has two seperate pumping elements inside, and one of them was cavitating with air, even though there only one pick up for them both.
Just been down the road and the potholes must have been filled in down our street cause it rides like its on air, at the back at least.
Also the sinking on start up seems to have gone. Was it the valve or the the 3 spheres....? I dont know, but I do know I am a few quid lighter.
The back shows up the front now....oh well, job for next month...!!
Many thanks for all your help.
Jon

royzels · Post by **royzels** » 07 Mar 2005, 23:14

Hi,
Had similar problems with my Xantia. Just had replaced the two accumulator sheres, and the rear height corrector replaced, seems to have done the trick, but only time will tell. Cost at Dealers, £300.00. Contact me if you require further information.
Royzels.