Xantia Suspension Strange Behaviour Help ASAP Please

thomp1983 · Post by **thomp1983** » 25 Jun 2007, 21:45

good evening, wondering if any of you knowledgeable folks could help with a suspension problem im having on a '97 citroen xantia 1.9td. basically the front or rear suspension will behave randomly. the car has just had it's accumulator sphere replaced, and the lhm fluid replaced. i have checked the white plastic clips are present on the linkages and heavily lubricated the linkages.

i have taken the following notes and measurements on the suspensions settings and behaviour, ive referred to the settings as 1,2,3,4 with 1 being the lowest setting and 4 the highest.

from starting the car and putting it on setting one, both the front and rear suspension sits down correctly and measures, front 31cm from arch to wheel centre approx, rear 24.5cm approx

then put it to setting 2 (normal ride height) the rear rises up but the front stays down, front 31cm, rear 32cm

then setting 3, car sits up properly both front and back nice and level, front 40.5 rear 42.5

then setting 4, rear stays at 42.5 front rises to 45cm

thats what happens when you go through the settings,

if you go back to setting 1 (lowest) then, setting 2 it behaves as above, if you then go to setting 3, wait for the stop light to go out then put it straight back to setting 2 then the front rises to the normal ride height along with the rear and measures front 38.5 rear 38.5cm

if you go from setting 4 (highest) to setting 3 then the front drops down to the bump stops and the rear sticks up on high.

if you just set it to normal height then the rear works properly and if you drive carefully down the road a few metres the front end then sits up properly, but won't do it if you rev the engine stationary.

the fluid level shows up to the top of the filter in the reservoir when the suspension is on lowest which i believe should be enough fluid. i have tried to bleed the system by doing the following, set to highest, hold revs at 2.5k and undo bleed screw half turn, get a whistling leave it undone a minute then tighten back up, is this correct or should i be waiting for fluid to be expelled or is there another method? there are no visible leaks in the system and i have checked carefully so am now lost as to the cause.

and another minor problem, the car can be difficult to start when warm, it starts perfect from cold but turns over alot when warm, any ideas?

any help would be gratefully received the car is going to france 2mrw and although the problem aren't going to stop that id like to fix them 1st if possible

cheers
chris

Mandrake · Post by **Mandrake** » 25 Jun 2007, 23:09

The behaviour of the rear suspension sounds normal - its not unusual for nothing to happen if you go from position 4 (fully up) to position 3 (intermediate) due to the way the override linkage works.

(In intermediate position it will generally only ever correct upwards, not downwards)

On the other hand the front is not behaving correctly at all - it sounds like either the manual override adjustment is way out, the front height corrector assembly is seized, or both.

To sort it out you need a pit or a hoist to safely access the front height corrector with all 4 wheels on the ground. (Never go under the car when there isnt enough clearance for you to fit with the suspension right down)

I'd start by checking the spring assembly attached to the height corrector and giving it a good dose of penetrating lubricant to make sure its freed up.

Next I'd slacken the manual override adjustment clamp - this is the clamp on the long rod that travels the length of the car and connects to the manual height lever.

Now check and see if the automatic height correction works properly - eg you sit on the front (the middle with the bonnet open, not on the wings

) and see that after a few seconds the height comes up again, then get off and see that it goes down again.

Assuming this happens the next thing to do is to check and adjust the height - there are lots of recent threads about how to do this safely, and also diagrams of where to measure the height properly, as the height setting is +7mm/-10mm. This is done with the middle clamp on the rollbar.

Once you're happy the ride height is correct its time to adjust the manual override linkage - with the height lever at normal height (position 2 in your scheme) and the car at normal height you slide the link rod along until the peg in the slot of the height corrector assembly is exactly half way along the slot.

This can be a bit difficult to see without a small mirror so if you can't see it just measure how far it will slide each way (put a scratch mark on the rod where it goes into the clamp) and set it to the middle and then tighten the clamp.

Regards,
Simon

PS just read where you said you're going to france tommorow

that doesn't really give you much time to sort it out, and I would NOT be driving the car long distances with either the ride height right up or down, definately unsafe, and could do serious damage to the car too...

deian · Post by **deian** » 25 Jun 2007, 23:11

you are bleeding it incorrectly, you need to bleed it with the LOWest setting, this means the weight of the car will force all the fluid from the struts back into the resevoir where all the bubbles will expel, you don't need to open any valve, although some people think it helps, and don't overtighten the nut either.

as for checking the fluid level, you are doing this the opposite way too, you need to check the fluid level with the suspension HIGH, this means that all the fluid will be in the system (mainly the struts), so it will go from the resevoir, this is when you need to check the float, make sure it is between the two red marks, be careful if it doesn't move at all, the float may be stuck with grime.

so check level with car on high, THEN bleed, car down (leave a couple of minutes, open the plug in the resevoir and watch for any small bubbles/froth), then car up, car down, and repeat a few times, 6 times should be enough, again, i'm not sure about the bleed nut, someone else will clarify, i think it is there for a more advanced reason

good luck, let me know how you get on

jeremy · Post by **jeremy** » 25 Jun 2007, 23:48

The bleed screw on the regulator has 2 functions - firstly it enables the accumulator to be depressurised for service and secondly it enables fluid to be circulated through the pump and the first bit of the circuit which is handy for priming the pump and purging that bit of the circuit of air. Once the car has risen that job has been done.

NEVER remove the bleed screw - there is a ball bearing behind it which will be lost. 1 to 1/2 turns is enough.

Xaccers · Post by **Xaccers** » 26 Jun 2007, 08:57

When I changed the accumulator on my 2.1TD, the front started acting like a pimpmobile, jumping up and down, until I did sufficient citrobics to clear any air out.

thomp1983 · Post by **thomp1983** » 26 Jun 2007, 18:23

the float level doesn't work, it nevers moves at all regardless of setting. i checked it on lowest to make sure the fluid didn't force itself out the resevoir, when on highest it is about 2/3rds up the filter in the resevoir. have done citorobics quite a few times will little change

the car can be put to normal height via going to 3rd setting then 2nd setting and drives fine and is definately of the bump stops.

quite sure the linkages aren't seized ive watched them carefully (and safely) numerous times and they both seem to have full movement up and down. will try bleeding it with the car running and in lowst setting then doing more citorobics

cheers
chris

Mandrake · Post by **Mandrake** » 26 Jun 2007, 21:17

thomp1983 wrote:the float level doesn't work, it nevers moves at all regardless of setting. i checked it on lowest to make sure the fluid didn't force itself out the resevoir, when on highest it is about 2/3rds up the filter in the resevoir. have done citorobics quite a few times will little change

If the tank is still 2/3 full when the suspension is on high, then the tank is too full I'm afraid. It's a common misconception that the tank should be mostly full when the level is being checked - in fact the tank is almost empty when the suspension is at full height and the float is calibrated for such.

The floats don't give any trouble IMHO. If you twist the float it will unclip and come out - then when you see what it consists of you'll see that it can't fail to work...

the car can be put to normal height via going to 3rd setting then 2nd setting and drives fine and is definately of the bump stops.

This behaviour still points towards either the manual override adjustment at the front being set wrong, (relatively easy to check with a pit) or the height corrector linkage a bit seized. Sorry. Just because it moves doesn't mean its moving smoothly.

quite sure the linkages aren't seized ive watched them carefully (and safely) numerous times and they both seem to have full movement up and down.

Where are you watching the linkages ? On the front height corrector its nearly impossible to see the actual spring linkage that goes from the plastic clip to the height corrector when it's in situ.

If you've been watching the linkages have you checked the location of the peg operated by the manual override linkage ?

will try bleeding it with the car running and in lowst setting then doing more citorobics

Won't have any effect on having to shift the lever from 1 to 3 and back to 2 to lift up.

Regards,
Simon

thomp1983 · Post by **thomp1983** » 26 Jun 2007, 23:29

ill need to pass all this onto my stepdad in france who's got the car so it may take awhile to get some more respones

cheers
chris

MikeT · Post by **MikeT** » 27 Jun 2007, 16:53

Mandrake wrote:If the tank is still 2/3 full when the suspension is on high, then the tank is too full I'm afraid.... in fact the tank is almost empty when the suspension is at full height and the float is calibrated for such.

The floats don't give any trouble IMHO. If you twist the float it will unclip and come out - then when you see what it consists of you'll see that it can't fail to work...

Simon

Hi Simon, I think you've just diagnosed my car

When I bought it, the float was too low and I added about 250ml. After a drive, it showed low again and added the same again. Another drive later saw the same repeated. A total of about 700-750ml went in but ever since, the float now shows an excess.

Is this cause for concern? I'll remove the excess before next drive but should I be inspecting or suspecting any parts that may have suffered?

Thanks, Mike

Xaccers · Post by **Xaccers** » 27 Jun 2007, 17:11

Too much LHM is likely just to cause some over spill of the excess when you set the car on low (as the LHM is returned to the resevoir then).

MikeT · Post by **MikeT** » 30 Jun 2007, 15:56

As LHM was not overspilling I decided not to drain the excess.

While doing other jobs yesterday, I noticed my float is playing tricks on me! Usually, when set to HIGH, the float remained at the very top of the sight glass indicating overfill.

However, leaving the engine running for a while, it does lower itself but in very small increments until it is showing the correct reading - dead level with top red mark.

I noticed the float only drops after the actuator(?) has clicked... and it takes several of these to attain the correct reading.

Does anyone know what causes this?

jeremy · Post by **jeremy** » 30 Jun 2007, 16:17

Yes - its due to compression of the gas in the spheres.

When the suspension is set to high the height correctors are set to open and the output from the pump goes straight to the struts - and pumps and pumps. All that retrains things is the mechanical strength of the chassis which limits strut expansion and the gas in the spheres.

Not really a good idea to leave it pumping for long on max - something might break or the sphere diaphragm rupture.

The maximum LHM level isn't critical. What is important is that there is enough in the reservoir.

MikeT · Post by **MikeT** » 30 Jun 2007, 16:51

Ah good, something that doesn't require money thrown to be thrown at.

Thanks jeremy.

Mandrake · Post by **Mandrake** » 01 Jul 2007, 01:27

jeremy wrote:Yes - its due to compression of the gas in the spheres.

When the suspension is set to high the height correctors are set to open and the output from the pump goes straight to the struts - and pumps and pumps. All that retrains things is the mechanical strength of the chassis which limits strut expansion and the gas in the spheres.

And the pressure regulator, which limits the pressure to 170 bars.

Not really a good idea to leave it pumping for long on max - something might break or the sphere diaphragm rupture.

Highly unlikely - the hydraulic system is designed to handle well in excess of the maximum regulated system pressure. (Safety margins in design...)

The only risks are spheres that are VERY low in gas pressure may finally have their diaphrams go pop, but that would have happened soon in driving anyway, as they would be very close to being stuffed already, and if the front strut top mounts are very rusty/perished, that may be the final straw for them to let go - but if they are that close to dying they aren't to be trusted anyway, and would probably let go during driving! (And I know which I'd prefer...)

Healthy spheres and healthy strut tops are in no way harmed by putting the suspension on maximum height. (While stationary of course!)

And to Mike's original question - yes it can take some time after the car appears to have reached full height for the float to drop to give a correct reading - this is because oil is still being pumped into the spheres even though the height isn't rising any further. When you hear the regulator click you can then check the float.

Regards,
Simon

MikeT · Post by **MikeT** » 01 Jul 2007, 09:35

Mandrake wrote: And to Mike's original question - yes it can take some time after the car appears to have reached full height for the float to drop to give a correct reading - this is because oil is still being pumped into the spheres even though the height isn't rising any further. When you hear the regulator click you can then check the float.

Regards,
Simon

As I said, mine took several clicks before the proper level was shown - quite a few minutes. Would that indicate anything suspect? I was told the two front spheres were recently replaced if that helps. Could it be related to the front height corrector popping off it's plastic arm every now and again? Thanks Simon