Guess What - Xantia Suspension!

Brodie_76 · Post by **Brodie_76** » 05 Jan 2005, 06:02

Hi all, first post so please be gentle!
May I start by quoting myself on another board regarding my friends Xantia Estate 2.0 SX on a '99 "T" reg: -
<blockquote id="quote">quote:<hr height="1" noshade id="quote">"Hi all,
A friend owns a Citroen Xantia estate 2.0 on a 99 "T" reg.
His youngest (who cannot keep his hands to his self, and IMHO deserves a good slap, right after his father for letting him "play" in the thing in the first place) was sat in the car a couple of months back and was playing with the height adjustment lever for the hydroactive (haha) suspension.
Without the engine running.
Since that time, the car is handling like a fully greased pig that knows it's on its way to slaughter, and is bouncing around making the whole family feel sea sick on all but the most billiard-table flat roads (of which in good ol' Bristle there aren't many)
Now, I thought maybe devil-child may have cavitated the hydraulic system/suspension control valve with his attempts at playing "hangar pilot" with his daddy's car, and it has fallen to me to sort it out - they have no money for a Citroen dealer to look at it, and the car is a definite MOT fail in it's current state.
So assuming I don't ram the steering wheel over the kids head and get carted off to la-la land, and I attempt to diagnose the problem, does anyone (please!) have a clue what I could possibly look at to avoid introducing my friend to "Big Bill"?
He was approached by one of the other dad's at the school the other day, who is an MOT tester, and he said something along the lines of "Your hydoactiv suspension spheres have gone haven't they?" to which he was faced with a car full of blank looks, and questioned "What?"
He said "I saw you bouncing along the road, it's a common fault on Citroen's with that ****ing stupid hydraulic system instead of good old springs and shocks" - I hasten to add he's not a Citroen MOT chap either.
So it looks like the litte dahhhh-ling has cost his daddy £200 in parts alone (!) for five minutes fun.

(
So, does anyone know how I can test whether that is the likely cause of the problem, or can anyone suggest alternatives to look at?
Many thanks for reading, sorry for the rant, many thanks in advance for any advice,"
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The reason I am asked to sort it out is that he knows I have in depth knowledge of (aircraft) hydraulic systems, and expects to get it sorted out for next to nothing.
So a good starting place (I have searched this forum, BTW, but can't find anything specific about the whole lot of problems) is the suspension spheres, however if I'm going to be stripping a lot of stuff out, then I may as well try and sort the lot out!
He had a leak from the anti-sink valve when he got it 18 months ago, which I replaced, I followed the procedure in the Haynes book of lies to depressurize the system, and still ended up with a shower of green LHM - can anyone venture as to why?
Also the anti-sink valve doesn't work! The back end seems to sink at an alarming rate when the ignition is stopped - is that also spheres or something else?
On top of all that (he really looks after his cars - can you tell?) the ride height seems to have difficulty adjusting - it's very slow and painfull to watch and the rear looked low today when he came down to my place.
Many thanks for your time
Brodie

DoubleChevron · Post by **DoubleChevron** » 05 Jan 2005, 06:15

C'mon Guys,
the car is just sitting at the wrong height. The kid playing with the height lever should not have hurt a thing.
My bet is the linkages are seized under the car or the plastic link to the rear height corretor has jumped off.
Most certainly the fix is 'free'. Height correctors don't break just because someone moved the lever inside the car.
Citroens ride like sh!t and handle poorly if they are sitting to high at one of the ends. Try moving the height control lever up & down and see if the linkages free up. It'll then drop back to the correct height.
Simple free fix that only requires ramps. DO NOT get under a hydraulic Citroen that is not supported. Also do NOT let any 'specialist' charge you a sh!tload for 'new hydraulic parts'. NOTHING should be needing replacement (unless you lucked out and by sheer bad timing a sphere did rupture it's membrane --This is totally unrelated to the height control lever being moved !!). In this case the corner of the car with the dead sphere will be like concrete. There will be NO movement in it at all.
seeya,
Shane L.

Brodie_76 · Post by **Brodie_76** » 05 Jan 2005, 10:31

Thanks for the reply.
I forgot to say that I have tried cycling the system (I initially thought that the child may have cavitated the system - I hate to say it but I despise french cars {from an engineers point of view} so don't know the hyd system on these at all) more than a few times, as usually - air is system, bouncy controls. So the height control has been cycled lots of times.
The car bounces like you wouldn't believe - if it was a normal setup I would be changing all four shocks on it as all damping has gone altogether - any more thoughts please?

wonderd · Post by **wonderd** » 05 Jan 2005, 12:18

The hidraulic system is not a stupid system at all, it is a lot more comfortable then the 'good old springs and shockers', it is true that sometimes the system fails but in general it's a lot better ride then most of the other vehicles...
most of the mechanics who does not 'like' citroen, feel like that mainly because they don't know how to fix them, they rather fix the easy cars that are very boring in my (and other's) opinion.
Elad.[^]

alan s · Post by **alan s** » 05 Jan 2005, 12:27

Brodie,
For some reason I get the feeling that you really want someone to tell you that this kid "cavitated" the system and I'm afraid it ain't gunna happen.
These hydraulic systems are so basically simple that it is almost an impossibility to do this and short of a sphere collapsing as has been suggested, the possibility of a height corrector linkage either breaking or popping off is the most likely scenario.
My son bought a BX a few years ago & it was like this, very bouncy. I adjusted the height and it has ridden perfectly ever since. I presume the suspension adjustment inside the car is set to normal ride? I ask this as there are these myths about Citroen suspensions that people think they can do all kinds of mystical things such as being totally collapssed when being drven or even driven at teh highest setting both of which are true to a point but will cause damage as well as an indescribeabley rough ride.
It may also be worth a look at this for some clues if in fact the height corrector limkage turns out to be OK.
http://web.actwin.com/toaph/citroen/work/work.html
The green shampoo you got when you changed the sphere was possibly from the fact that if it had ruptured the membrane inside, the LHM was trapped above it under pressure and as a result it came out (possibly up to 200mls) with a pent up pressure behind it and the rupture acting like a capilliary.
Alan S

ItDontGo · Post by **ItDontGo** » 05 Jan 2005, 14:05

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Brodie_76

Thanks for the reply.
I hate to say it but I despise french cars {from an engineers point of view}.
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I was awarded the best student in the Institution of Mechanical Engineers when I graduated and I think the Citroen Hydraulic Suspension System is an incredible achievement on a mass produced range of road cars.
It would be easy to make a one off hydraulic system and not be able to make it effective and simple enough to be financially viable to fit on a mass produced car. Citroen made their system simple and effective at low cost which is to be applauded.
Looking at German cars with an Engineer's and Business perspective it is difficult to really credit them in a way which their reputation would lead you to believe they should be.
If you say they are better built, relative to a French car, then this is a poor business and engineering approach as it is wasteful to over engineer a system. A car has a 10 year lifetime and designing it to exceed this is a cost which is unnecessarily incurred and bad practice.
The main faults with new cars are with the electronics and all car manufacturers suffer as electronic components generally do not vary in quality between major electronics manufacturers.
The extra expense of a German car does not go on innovative developments rather it goes on unnecessary engineering and, the curse of all humans, prestige.

NiSk · Post by **NiSk** » 05 Jan 2005, 14:22

A '99 Xantia requires the engine to be running and normal hydraulic pressure to have been acheived in the system before the height control lever will do anything. I also think you should start by looking at the rear axle control linkages.
//NiSk

Panjandrum · Post by **Panjandrum** » 05 Jan 2005, 14:25

Brodie,
You are on dangerous territory here expressing negative opinions about French engineering and hydraulics!
Some more information perhaps - try this with engine running -
When you sit on the back of the car does it sink gently then rise again?
When you sit on the bonnet.......?
Any variation between left and right? Front and back?
The expectation here is that the problem is in linkages and /or wrong setting of the suspension control, not in the hydraulics.
PJ

fordsone27n · Post by **fordsone27n** » 05 Jan 2005, 15:17

Most people seem to slate the Citroen suspension system because they do not understand how it works. Although not normal by automotive standards it is relatively simple. A logical approach is all thats needed.
Assuming all fluid levels are correct, I think i'd first check to ensure the linkages to the height corrector valves intact and not seized, and that the height at least responds to changes in the lever position. Once this has been achieved you can check the height by measurement and height correcter action by loading the boot while it is running to see if it compensates for the weight. Only then can you start to see if the spheres are shot.
Adrian

modi · Post by **modi** » 05 Jan 2005, 15:18

my front car will rise first and then the back, is that normal cos i have a bouncy car as well

NiSk · Post by **NiSk** » 05 Jan 2005, 17:08

No, the normal procedure is for the rear to rise first, since it's a good bit lighter than the front. If you have a stiff rear end, you should also check out as above.
//NiSk

uhn113x · Post by **uhn113x** » 05 Jan 2005, 18:11

<blockquote id="quote">quote:<hr height="1" noshade id="quote">He said "I saw you bouncing along the road, it's a common fault on Citroen's with that ****ing stupid hydraulic system instead of good old springs and shocks"
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While we are at it, let's reinstate solid tyres, crash boxes, no electric starter - they don't execute Luddites now [}:)]
<blockquote id="quote">quote:<hr height="1" noshade id="quote">I hasten to add he's not a Citroen MOT chap either.<hr height="1" noshade id="quote"></blockquote id="quote">
Evidently; nor even a mechanic?

Brodie_76 · Post by **Brodie_76** » 05 Jan 2005, 19:13

Hi guys, I had no intention of upsetting anyone, but let me tell you my bona fides: -
I'm an airframe engineer in the RAF, and have been for 9 years. What I've been taught about hydraulic/hydropneumatic systems (and forgotten) is probably more than most.
Bear in mind all Military aircraft have hydraulic systems for their control, so I know the nuances of hydraulics, and, for instance, how often hyd systems break down.
I dislike french cars, as to me they are not very well thought out - prime example the plastic clip that holds the clutch cable to the pedal - replaced that on his Xantia 2 months back and what a hell of a stupid design that is! Also a hydraulic system that runs power steering, brakes and suspension from a common resevoir/system with apparently (from what I have read on here) no fail safe mechanism for low fluid/fluid loss to provide brakes in the event of an emergency!
I'm a japanese afficianado, as (generally) their cars (and bikes) are well thought out from an engineers point of view - little things like cut-out to aid removal of parts prone to breakage.
Thanks for the help - I really do appreciate it, however I was transferring my knowledge of aircraft to a car when I said about the kid playing in the car - we get hangar pilots all the time trying to force aircraft control surfaces to move when they're in a state of hydraulic lock (i.e. the anti-sink mechanism) and they can force cavitation of the system if they're not careful - I got it wrong, however like I origianlly said I don't know the system.
FWIW the same kid has been swinging off the open front doors and has caused one of the mountings to crack, net result is probably also an MOT failure as the doors are drooping from where they should be - the top rear of the window frame of the drivers door is gouging a big groove in the top forward edge of the rear door.
That again is a reason to dislike this car - the doors are welded in place as opposed to bolted - not a brilliant design.
It's not the child I have the issue with really - it's his father for letting him play with the car - it's not a toy, and for an 8 year old can be very dangerous things.
Thanks for the help
Brodie

Brodie_76 · Post by **Brodie_76** » 05 Jan 2005, 19:17

Alans,
Perhaps you misunderstood - it was the anti-sink valve I replaced not the sphere.
Would it have been stored pressure in the sphere at this section that escaped?
Thanks
B

Kowalski · Post by **Kowalski** » 05 Jan 2005, 19:26

Citroens (like all cars today) are designed to be put together easilly and cheaply on a production line, thats why car ownership is as high as it is in the UK, cars are cheap. Any little design features that accidentally help maintenance are usually provided to make the car easy to assemble.
The Xantia does have several safety features so that its brakes are not as dangerous as you make out. Firstly, there are the STOP, hydraulic pressure and fluid level lights, the driver is told when the hydraulic pressure or fluid level is low and is told to stop. Secondly, the rear brakes are supplied with pressure from the rear suspension, not the pump and accumulator sphere, this means the rear brakes will work as long as there is any suspension height. Thirdly the hand brake operates on the front wheels, most cars handbrakes operate on the rear wheels, a front wheel handbrake is MUCH more powerful.
What safety features does a conventional braking system have against fluid levels being low or lost that the Xantia doesnt?
As for the welded door hinges cracking, this was a known fault with the Xantia, not a design problem but a manufacturing defect, the hinges were not welded on sufficiently strongly on many estates.