Overhauled Rear H/C & New Spheres, still problems

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xantiagreen
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Overhauled Rear H/C & New Spheres, still problems

Post by xantiagreen »

Hi, recently had the rear corrector overhauled with a new seal kit, also new regassed spheres all round since then car has never sat properly at the rear, when I switch to highest setting works fine, when i then drop to normal ride height the front end drops fine but rear stays in same high position, waited 2 minutes and nothing. When I drop tp lowest setting front drops fine and rear takes it time but eventually does drop complete takes just under a minute,

I can then raise it to the normal drive height and it levels out properly, but if i load the car the rear and front compensate and everything looks good, but when I park up with handbrake on and engine switched off or on whilst unloading the rear height is raised.

Does the rear height corrector need adjusting and how, or is it the control arm/cradle, previous to buying this car, MOT advisory was that the rear suspension was damp, but then again the rear spheres were pretty low on gas. I have spent almost 600 on getting the car right, but this rear height niggle is annoying.

Please see pics " onclick="window.open(this.href);return false;

Thanks in advance.
Faz

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Re: Overhauled Rear H/C & New Spheres, still problems

Post by RichardW »

It's definitely too high....

As I said in the previous post - what is a seal kit? That HC doesn't look like it's been touched, there doesn't appear to be any witness marks on bolts or pipe unions to indicate it's been out. Anyway, if it went into the garage and they did something to the HC, but have beggared up the rear height correction at the same time, then take it back and get them to fix if - FOC!!
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Re: Overhauled Rear H/C & New Spheres, still problems

Post by xantiagreen »

RichardW wrote:It's definitely too high....

As I said in the previous post - what is a seal kit? That HC doesn't look like it's been touched, there doesn't appear to be any witness marks on bolts or pipe unions to indicate it's been out. Anyway, if it went into the garage and they did something to the HC, but have beggared up the rear height correction at the same time, then take it back and get them to fix if - FOC!!
Seal kit is Height corrector rebuild kit (diaphrams, boots and rings http://www.citroenpieces.com/products.asp?cat=22&pg=3" onclick="window.open(this.href);return false;
I've been spraying all sorts up there to try and free it, thats probably why it looks as though it has not bee ntouched. I am taking it back to show him but worried things are going to worsen, the mechanic is a friend and citroen specialist (don't ask how).
Faz

90 Ax 1.0 Red
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Temporarily driving Polo 1.9sdi

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Re: Overhauled Rear H/C & New Spheres, still problems

Post by citronut »

its more likely to be the cradle linkage/turrets not the height corrector its self,

these turrets really need to be floppy loose when they are off the car/not in circuit/connected to the linkage on the car,
Regards, malcolm.

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Re: Overhauled Rear H/C & New Spheres, still problems

Post by Mandrake »

xantiagreen wrote:Hi, recently had the rear corrector overhauled with a new seal kit, also new regassed spheres all round since then car has never sat properly at the rear, when I switch to highest setting works fine, when i then drop to normal ride height the front end drops fine but rear stays in same high position, waited 2 minutes and nothing. When I drop tp lowest setting front drops fine and rear takes it time but eventually does drop complete takes just under a minute,

I can then raise it to the normal drive height and it levels out properly, but if i load the car the rear and front compensate and everything looks good, but when I park up with handbrake on and engine switched off or on whilst unloading the rear height is raised.
The part I've highlighted in bold suggests to me that the height adjustment is actually correct - this is the adjustment of the clamp on the roll bar, however it is only stopping at the correct height when it rises not when it falls.

That's only really going to be one of two things - either the cradle is still sticky despite all the lubrication in the photo, so is having trouble returning to centre from one direction, or the manual height override adjustment is way out. That's the clamp at the bottom of your last picture which clamps onto the rod that travels the length of the car. Is there any evidence that this clamp adjustment has been changed ?

If it was me first thing I'd try would be to loosen that bottom clamp in the last picture right off so that the rod can slide freely in the clamp, and make sure that the spring arm that it's attached to can move freely and that it sits in the middle of its "slack" when the car is resting at normal ride height and the manual height control lever is also at normal height. (Obviously only do this while the back of the car is safely up on ramps so you don't get squished to death!)

If this manual adjustment is out far enough it can cause the height not to correct properly in one direction but still work in the other direction - in your case it rises to the correct height but won't fall.

Another thing you could try before the above would be to get an assistant to physically hold the manual height lever on the centre console still at about half way between the fully down and normal ride height setting - then try alternately sitting on the boot and getting off while the engine is running to see if it now returns to the correct ride height in both directions - if it does its definitely the manual override adjustment being way out!

If you still can't get it work properly at any partial position of the manual height lever its probably the cradle linkage binding on one half of its movement range.
Simon

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Re: Overhauled Rear H/C & New Spheres, still problems

Post by Xaccers »

To set the manual height clamp, the pip on the end of the linkage needs to be bang in the middle of the square hole in the arm that comes out of the height controller when set to normal height.
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Re: Overhauled Rear H/C & New Spheres, still problems

Post by Mandrake »

Xac wrote:To set the manual height clamp, the pip on the end of the linkage needs to be bang in the middle of the square hole in the arm that comes out of the height controller when set to normal height.
I really need to check the adjustment of the front manual override linkage on mine...

While driving, from time to time I notice the car is sitting a bit high at the front for long periods of time - you can visibly see from the view angle out the front window that the front seems a bit high and the ride starts to get a bit fidgety with left/right rocking over bumps, if I push the manual height lever right forward for just a couple of seconds the front immediately drops a bit, the view looks correct out the window and the ride improves greatly and stops fidgeting.

At first I thought the ride height was just a bit too high at the front but it looks correct when parked, so I measured it using the full correct factory procedure where you measure the wheel radius, subtract a quoted figure, measure from the ground to the suspension underbelly etc... a method that eliminates variations due to tyre radius/pressure and so on and is very accurate.

The result ? The static ride height at the front is absolutely spot on, and I mean within about 2mm of the correct figure! There's less than 5mm of hysteresis as well, (the difference between up and down correction) which is excellent. I repeated the measurements multiple times and it came back to the exact same figure every time within a millimetre or two.

So how come its sometimes visibly and obviously too high while driving ? I've been thinking about that and I believe that its due to the manual override linkage being significantly out of adjustment, causing a "ratcheting" effect while driving - but not so far out that it affects corrections when the car is parked, for example causing the height to stick too high like xantiagreen's car.

Normally when the linkage can move freely both ways the ride height fluctuations are averaged out by the height corrector and its linkage resulting in no net change in ride height as you traverse dips and rises in the road. (At least at the front suspension which doesn't have to cope with acceleration squat)

But if the manual linkage is offset towards the high direction far enough it biases the whole correction mechanism in favour of making upwards corrections - the height being just a tiny bit too low will cause an upwards correction but the height has to be a lot too high before there is a downwards correction.

So as the suspension moves up and down over large dips and rises in the road, every time the suspension compresses over a rise the height corrector makes a small upwards height correction, but during the corresponding dip in the road no downwards correction is made. The end result is that in response to an undulating road the ride height gradually "ratchets" itself higher and higher until its sitting noticeably too high, and will tend to stay that way.

When you get out of the car the ride height is now much too high due to the load change - high enough that it does trigger a correction despite the maladjusted manual override, the car returns to the correct normal ride height, so there's no evidence that the height was sticking too high while driving after the car has been parked...

As well as road undulations triggering this, the Xantia has the well known trait of rising on full lock due to the geometry of the roll bar links and McPherson struts - the ride height will temporarily rise on full lock then correct back down when the wheels are straight again. However if this manual override bias is there it will make the corrector more keen than usual to lift the ride height when you turn onto a sharp lock, but much more reluctant to then lower it back down when you straighten out. I'm pretty sure I have noticed that the ride height is often too high and stays that way for a long time after using full lock. (eg you would expect it to go down again within 5-10 seconds after straightening out but it could stay that way for minutes or more)

Anyone else observed behaviour like this before, where the ride height measures correct when parked but seems to drift too high or low when driving ?
Simon

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Re: Overhauled Rear H/C & New Spheres, still problems

Post by xantiagreen »

Mandrake wrote:
Xac wrote:To set the manual height clamp, the pip on the end of the linkage needs to be bang in the middle of the square hole in the arm that comes out of the height controller when set to normal height.
I really need to check the adjustment of the front manual override linkage on mine...

While driving, from time to time I notice the car is sitting a bit high at the front for long periods of time - you can visibly see from the view angle out the front window that the front seems a bit high and the ride starts to get a bit fidgety with left/right rocking over bumps, if I push the manual height lever right forward for just a couple of seconds the front immediately drops a bit, the view looks correct out the window and the ride improves greatly and stops fidgeting.

At first I thought the ride height was just a bit too high at the front but it looks correct when parked, so I measured it using the full correct factory procedure where you measure the wheel radius, subtract a quoted figure, measure from the ground to the suspension underbelly etc... a method that eliminates variations due to tyre radius/pressure and so on and is very accurate.

The result ? The static ride height at the front is absolutely spot on, and I mean within about 2mm of the correct figure! There's less than 5mm of hysteresis as well, (the difference between up and down correction) which is excellent. I repeated the measurements multiple times and it came back to the exact same figure every time within a millimetre or two.

So how come its sometimes visibly and obviously too high while driving ? I've been thinking about that and I believe that its due to the manual override linkage being significantly out of adjustment, causing a "ratcheting" effect while driving - but not so far out that it affects corrections when the car is parked, for example causing the height to stick too high like xantiagreen's car.

Normally when the linkage can move freely both ways the ride height fluctuations are averaged out by the height corrector and its linkage resulting in no net change in ride height as you traverse dips and rises in the road. (At least at the front suspension which doesn't have to cope with acceleration squat)

But if the manual linkage is offset towards the high direction far enough it biases the whole correction mechanism in favour of making upwards corrections - the height being just a tiny bit too low will cause an upwards correction but the height has to be a lot too high before there is a downwards correction.

So as the suspension moves up and down over large dips and rises in the road, every time the suspension compresses over a rise the height corrector makes a small upwards height correction, but during the corresponding dip in the road no downwards correction is made. The end result is that in response to an undulating road the ride height gradually "ratchets" itself higher and higher until its sitting noticeably too high, and will tend to stay that way.

When you get out of the car the ride height is now much too high due to the load change - high enough that it does trigger a correction despite the maladjusted manual override, the car returns to the correct normal ride height, so there's no evidence that the height was sticking too high while driving after the car has been parked...

As well as road undulations triggering this, the Xantia has the well known trait of rising on full lock due to the geometry of the roll bar links and McPherson struts - the ride height will temporarily rise on full lock then correct back down when the wheels are straight again. However if this manual override bias is there it will make the corrector more keen than usual to lift the ride height when you turn onto a sharp lock, but much more reluctant to then lower it back down when you straighten out. I'm pretty sure I have noticed that the ride height is often too high and stays that way for a long time after using full lock. (eg you would expect it to go down again within 5-10 seconds after straightening out but it could stay that way for minutes or more)

Anyone else observed behaviour like this before, where the ride height measures correct when parked but seems to drift too high or low when driving ?
Is it ok to use de-greaser spray (Gunk/Comma) around the cradle and linkage area only that the spray will hit the boots on the height corrrector, thought it might cause a problem. I'm going to give it one more try and clear all the grease (as I didn't do before) and the clean wherever I can reach then use Plusgas spray (again is that ok to use) and let it soak in overnight and give it a few more doses of spraying then a good up n down workout. Failing that it's back to mechanic for him to ponder and fix my lovely citroen and not end up a citruin.
Faz

90 Ax 1.0 Red
90 Bx 1.7 TZD Green
92 Bx Gti BRG
90 Bx 16v Cream
96 Xantia 2lt 16v Sx Olive green
01 Xantia 110 Hdi
Storm Grey (SOLD 4/11/18)

Temporarily driving Polo 1.9sdi

All I want is a Bx Gti or 16v!
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Re: Overhauled Rear H/C & New Spheres, still problems

Post by isisalar »

Just been there with a dodgy height corrector which turned out to be a broken bush on the pivot. You may be lucky with a good wire brushing and lube up but from my recent experience I'd change the cradle complete. I was charged 1 hrs labour by the indy to change mine complete and Citroenxm supplied the replacement by post in about 2 days. He's offering some today in for sale and wanted for about £20. Full lube up and operation check can be done off the car before fitting obviously.
Not a job I would attempt myself but for an indy with equipment and understanding it's not a major job, 3 hydraulic connections, a few bolts holding the cradle on, and remove and re fit the dog bone. It's recommended to fit a new dog bone as well, £3 from Citroen. The pipe connections can rust in so give them a regular dose of Plusgas while you're down there. The blowtorch had to come out for one on mine.
Getting this done has made a major difference to the behavior of the car, well worth getting done.
Cheers
Paul
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Re: Overhauled Rear H/C & New Spheres, still problems

Post by citronut »

isisalar wrote: it's not a major job, 3 hydraulic connections, a few bolts holding the cradle on, and remove and re fit the dog bone. It's recommended to fit a new dog bone as well, £3 from Citroen. The pipe connections can rust in so give them a regular dose of Plusgas while you're down there.
you dont need to remove the actual height corrector, just undo the two 11mm bolts holding it to the cradle, and leave it attached to its pipes,
isisalar wrote: The blowtorch had to come out for one on mine.
Paul
i personally would not put the blow torch anywhere near a height corrector, as this will destroy all the rubber/plastic bits ,

obviously unless it was fully striped out before hand
Regards, malcolm.

current ride a BX 1.7 TZD estate
1986 MK1 BX 1.9na D Auto(in Mothman Andy's stable )
layed up roppy 1.9TD XANT estate, now gone to meet her maker
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1972 DS special been layed up aprox 31 years
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Re: Overhauled Rear H/C & New Spheres, still problems

Post by isisalar »

It was when the old one was being removed complete, corrector and cradle, so didn't matter about the seals. I was more worried about the proximity to the fuel tank!
Cheers
Paul
J reg 1.9d auto BX first Citroen
M reg 1.9d auto Xantia lx
N reg 1.9 td Xantia VSX Estate
T reg 2.0HDI Xantia Exclusive Estate Present car
M reg 106 diesel red
L reg 106 diesel white
02 Saxo 1.1i desire wife's present car(sadly now very ill cambelt gone- Doh)
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