Rear Suspension Puzzle

rlatarche · Post by **rlatarche** » 24 Oct 2009, 14:35

Guys, I wonder if you can help me with my little problem.

I have a Xantia 1.9 td SX 1996 and the Rear suspension on my car does not rise when the height adjuster is set to the normal ride position.

If I set it to the park position both front and back lowers to the correct height.

If I raise the setting to Full height both front and back raise to the correct height, If however I set it to normal ride the front will either raise or lower to the correct height but the back just sits at the last height asked of it.

If the car is set to Raised slightly both front and back raise to the correct heights.

I've had the sphere's replaced about a year ago, the ticking noise is over a minute between ticks and have tried several rounds of citrobatics.

I haven't had a chance to get under the car due to our lovely british weather but can you point me in some direction as i was under the impression the little plastic clip may have come off but due to the fact it adjusts to every setting except the normal height leads me to think that this may not be the case.

Any ideas/help would be greatly appreciated

Citroenmad · Post by **Citroenmad** » 24 Oct 2009, 14:41

Sound slike a sticking height corrector

Might just need freeing off with some wd40.

rlatarche · Post by **rlatarche** » 24 Oct 2009, 14:48

@Citroenmad. . . could you point me in the direction of the sticking height corrector?

citronut · Post by **citronut** » 24 Oct 2009, 15:47

there are two hight corectors, one on each axle and they are linked to the manual hight control and also to the front and rear anti roll bars,

the front one is pirched just above the rear centre of the front subframe,

and the rear one is at the centre of the car between the rear axle and the spare wheel,

its not actualy the hight corectors that stick, its the two spring loaded turrets each hight corector is linked to,

two turrets per H/C, one turret controls the maual hight adjustment and the other the self adjustment,

i dont belive it is possible to free these off long term in situe,

but it certainly wont hurt to try lubricating them

regards malcolm

rlatarche · Post by **rlatarche** » 26 Oct 2009, 08:42

It may or may not help with the diagnosis but either I made a mistake or something has changed. Only the Park or Workshop selections (i.e. the lowest and highest settings) now work. Does this still point to a duff height corrector or something else??

Thanks

Post by **CitroJim** » 26 Oct 2009, 09:58

Yes, it does. If you look under at the rear height corrector it is likely you'll find the white plastic link that looks like a dogbone has popped off. This links the height corrector mechanism to the anti roll bar.

Before venturing under, please ensure the car is very adequately supported on either ramps or axlestands as a sunnenly collapsing hydraulic Citroen can kill.

If the dogbone has popped off, it is rarely just a case of popping it back on and all being well. It points to a seizxure or stiffness in the height corrector mechanism as described by Malcolm. It will need to come off and be thoroughly cleaned and lubricated. although often you can get away with dousing it in WD40, working it vigourously until it is really nice and free and then lubricating it with thin spray grease.

I also recommend you replace the dogbone as they often suffer hair-line fractures in the ball cups and will continue to pop off or lead to random ride heights. They're available from dealers for pennies.

deian · Post by **deian** » 26 Oct 2009, 11:15

I'm with jim on this one, for what the clips are worth it is worth replacing it, i think they around £1.69.

I think your clip has popped off which is why it doesn't find the normal height, the reason it find highest and lowest setting is as follows, on the highest setting it will fully pressurise the system and fill up the struts regardless of the load in the back (which is only when the clip works).

Same goes with when it de-pressurises, all the fluid will go back to the lhm resevoir as the weight of the car weighs down on the struts (nothing to do with how the load in the back twists the anti-roll bar).

The way the height corrector mechanism works with the height control lever on the back doesn't mean it won't go fully up or fully down, but if it isn't clipped on (linked to the anti-roll bar) then it just won't keep it's 'normal' height when the load changes in the back (in relation to the anti-roll bar twisting under the new load).

Even with the clip broke the lever will still move a valve in the height corrector to pressurise the struts or de-pressurise, the clip comes into play afterwards and is only activated when the height control lever is set to the middle. If the clip isn't clipped on then the height corrector assumes it is on the lowest setting hence the car being on the floor.

Same goes with the intermediate height setting (or workshop or wheel changing setting), the lhm is pumped into the struts regardless of what the normal height is meant to be so both front and rear will go up bypassing the way the clip works.

When my clip broke on my old xantia I could put it up on the intermediate height to raise the rear and then back to normal (back off the pressure), the rear would then drop down a little bit but enough to keep the back at a higher setting that it was when it was on the floor and hence give a normal ride for a while, it was just to get the correct pressure of lhm in the rear struts so the spheres would work correctly. But with the clip not clipped on it wouldn't level off if the car moved up and down and then reset the bad ride. Hope that makes sense.

The metal ball the clip actually clips onto on the height corrector can rust/corrode meaning it will shrink and therefore pop the clip off. A new clip is hard to pop on. The reason the back one goes and not the front it because it is more exposed to the elements, the front on is hidden quite well so won't pop off, I haven't heard of one pop off yet, maybe someone else on here has.

Let us know how you get along.

EDIT: If you want to pop the clip back on, make sure the height control lever is set to normal, otherwise the clip will never even go close to reaching the the little ball it needs to pop onto. If it doesn't clip on you will need work out how the height control mechanism works and raise or lower the suspension by hand on the actual height control mechanism the suspension will take time to react and go up or down as you need it to. To do this you will need your car on a hoist, because if you make the height corrector lower the car you will be fatally crushed, the car WILL take time to react.

As jim said DO NOT EVER go under the car while playing with the height corrector unless the car is on a hoist or over a pit, this goes beyond saying support it with axle stands as in this case it's not the best technique. If you will play with the height corrector a proper commerical garage hoist or a pit is a must. When you are down there, take a good look at how all the mechanisms work with the height control lever and the plastic clip clamped around the anti-roll bar. It's very clever stuff.

rlatarche · Post by **rlatarche** » 02 Nov 2009, 09:13

Thanks for the info chaps, the height corrector does appear to be sticking as the problem cleared its self up for a short period, however this morning its playing up again. Yes i've learned the trick myself about fooling the car into high and low settings to get a ride height similar to the normal height to get it to the garage safely.

Can you guys point me to any decent posts/pics of the HC and how to take it off as the mechanic i'm using hasn't had much dealings with Citroens and needs a few pointers as usual the Haynes Manual is useless!

Thanks

citronut · Post by **citronut** » 02 Nov 2009, 13:28

its not likely to be the H/C its self more likely to be the mechanism/linkag/turrets

regards malcolm

rlatarche · Post by **rlatarche** » 02 Nov 2009, 13:47

Well we had it up on the ramps at lunch and the plastic cup had again popped off, the height corrector springs and arms seems to move freely. We cleaned it in situ with compressed air, plus glas and other grime cleaners. Lightly greased it up and checked over the plastic unit, no cracks. It seemed to click onto the balls with a nice click so will have to see what happens now. If it pops off again i'll replace the plastic part and take it from there.

Thanks for the very quick responses and wealth of info you guys/girls are willing to share with people like me who don't have much clue about the cars they drive.

Post by **CitroJim** » 02 Nov 2009, 21:42

Just for completeness, this is a picture of the height correctors:

No.2 is the rear but functionally both are identical. You can see clearly the mechanism.

Hope all will now be well after your cleaning and lubrication but if the link pops again, do replace it. Sometimes just removing it can put a small crack in the ball cups.

citronut · Post by **citronut** » 03 Nov 2009, 09:07

rlatarche wrote
"Lightly greased it up"

dont be stingey with the grease the more on there the better as it will stop the weather getting in

regards malcolm

pazauk · Post by **pazauk** » 15 Nov 2009, 17:51

Would like to say a big thanks to this topic had the same problem on my 2.1td today! thought it was going to be a big problem to fix! thank you all very much.

vince · Post by **vince** » 17 Nov 2009, 21:36

CitroJim wrote:Just for completeness, this is a picture of the height correctors:

No.2 is the rear but functionally both are identical. You can see clearly the mechanism.

Hope all will now be well after your cleaning and lubrication but if the link pops again, do replace it. Sometimes just removing it can put a small crack in the ball cups.

Handy picture Jim thanks

I take it number 71 are the bolts that mount the unit to the vehicle ?

Post by **CitroJim** » 17 Nov 2009, 21:48

Yes, 70 and 71 are the mounting bolts Vince...