Ride height and front self-levelling

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andycadabra
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Ride height and front self-levelling

Post by andycadabra »

After a little surgery on the leaking front height corrector, the front suspension seems to have returned to relative normality, although it's still seems a little on the low side. 16.6cm ground clearance is given in the manual but I don't know where this should be measured from. The lowest part of the Sill corresponds to this, but the front subframe it's about 13 cm and the lowest part of the exhaust system (the U bolt in the middle) it's about 11cm.
The self-levelling at the back is working fine - dropping 5 cm when I stand on the towbar and then rising 5 cm to compensate. There doesn't appear to be any self-levelling happening on the front suspension - climbing onto the front corner and results in a drop of about 1-1.5 cm, and the suspension seems not to rise to compensate as the back does, but because there's relatively more weight on the front because of the engine I don't know if that's normal?.
1992 BX 17TZD 130k
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andycadabra
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Re: Ride height and front self-levelling

Post by andycadabra »

The height seems to vary between the ride heights given above i.e 16.6cm ground to bottom of Sill, and 2.5 cm less, i.e. 14cm. The higher ride height gives a noticeably softer ride, and experiments so far seem to show that if left on normal it'll give the lower ride height, but if raised to a higher setting and then put on normal it will result in the higher one.
Any measurements of ride height in the normal setting would be useful to know..
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mat_fenwick
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Re: Ride height and front self-levelling

Post by mat_fenwick »

4 fingers slid in horizontally between the front tyre and wheelarch lip should give roughly the correct height. However, the absence of self levelling on the front, and the varied height depending on whether you're going up or down suggests something is still amiss.
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andycadabra
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Re: Ride height and front self-levelling

Post by andycadabra »

Thanks Mat - after further research waggling my A5 breakdown policy book between ground and sill at traffic lights, I've concluded that it definitely doesn't reach its correct height unless I make a brief visit to intermediate, and then drop down to normal.
I'd thought the front was a bit hard for a while, and I'd be surprised if others hadn't suffered from this phenomenon, whether they are aware of it or not.
It's a relatively minor inconvenience but It'd be interesting to know if it's a symptom of something more serious...
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Re: Ride height and front self-levelling

Post by Way2go »

Basically it still sounds like hysteresis created in the HC linkage due to stiffness, lack of lubrication or corrosion.
I found this to be an irritating problem that was finally solved by spraying the linkage (from the wheel-arch, not from above) firstly with 3in1 Penetrating Oil, letting that work in and then spraying with lithium grease.

This was the only solution (in my experience) that did not see the same problems re-appearing soon after. Also, if there is a lot of clag on the linkage it may be a good idea to wash the linkage first with Gunk on a long handled brush before applying the Oil & Grease sprays. :D
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Re: Ride height and front self-levelling

Post by andycadabra »

Thanks for that good advice Way2go. I have already tried spraying it with spray oil, but from under the car - I have some 'Gunk liquid wrench' dismantling lubricant in aerosol form, I presume that should suffice as penetrating oil? So I'll spray that from the wheel arch today. I guess by clag you mean mud? I don't have much contact with the stuff where I live!

I did replace the seals on the accessible side of the front height corrector, and I originally tried to stop the leak by tightening the nut on the spindle, which of course didn't work, but I don't know if I did some damage in the process. I'm not sure if the problem existed before I did that work, and wasn't even sure how tight it should be having replaced the seals.
1992 BX 17TZD 130k
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Re: Ride height and front self-levelling

Post by andycadabra »

I sprayed plenty of dismantling lubricant from the wheel arch, and thought that had sorted it couple of days ago but it's still playing up, sometimes the front doesn't rise at all without a visit to the intermediate setting. I'll be replacing the accumulator sphere and the 2 front spheres (which have lasted 10 years) in the next couple of days. I don't suppose that'll make a difference but we'll see..
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Re: Ride height and front self-levelling

Post by andycadabra »

got my new accumulator sphere and fitted it - so the cars a lot happier but predictably hasn't solved the height problem. I got it for just £23, brand-new made by Lizarte, from Citroen Vantage in Wimbledon aka Citroen parts London, Neil who runs it reckons it's down to dirt in the height corrector, on the basis that it's one of the lowest parts of the hydraulic system.

I came across a photo[see below] I took when the garage had the engine out, [to help me repair/replace a coolant hose]. interestingly the cap was still on the height corrector, before it got lost and the membrane damaged, probably when the new engine went in.
Basically, they had decided the only way to get the engine out was from underneath, [in the process buggering one of the heater tap spouts which lead to a nightmare], but I wonder if they knocked something out on the height corrector, or whether the position of those weird curly spring like tubes has a bearing on height correction?

http://i951.photobucket.com/albums/ad35 ... ad/2-1.jpg
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Re: Ride height and front self-levelling

Post by docchevron »

the control arm runs through a bush on the subframe, the wear horrifically and cause all manner of ride height issues, I'd be looking at that, also the security of the HC itself, the bolts can work loose and give interesting results
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Re: Ride height and front self-levelling

Post by citronut »

sounds to me you have rotated the H/C spindle whilst tightening the 8mm nut on the accessible side of the H/C, which in turn has moved the ball coupling at the other side of the H/C were it sits in the linkage,

this in turn is causing drag on the connection between the H/C and the linkage,

regards malcolm
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Re: Ride height and front self-levelling

Post by andycadabra »

Docchevron - that's interesting - Where is the bush in relation to the height corrector and where the rod meets the antiroll bar? Nearer one or the other?.

Malcolm that sounds plausible! I did some more spraying today from the wheel arch, while changing a droplink, and it's quite possible to feel the back of the height corrector, although not see it because there's a shield in the way. It might be possible to take a photo the back of it, and if I post it hopefully you might be to be able to tell me..
Am I right in thinking the height corrector is activated by the amount the antiroll bar is twisting?
I must say it's quite random. Sometimes it doesn't rise at all at the front, and sometimes after a short delay finds its way up to the correct height, but mostly it rises to about an 30 mm less than it should and needs to go to intermediate setting and then back to normal.
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Re: Ride height and front self-levelling

Post by docchevron »

the bush on a bracket off the subframe, MUCH nearer the HC than the roll bar, if you follow the rod from the ARB you'll see it passes through said bush before locating in the HC. I've yet to see a BX that doesn't have a significantly worn bush, and it can and does cause all manner of height control issues
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Re: Ride height and front self-levelling

Post by citronut »

did you have this issue before fixing the leaky H/C,

if not it has got to be what i said / \
or you have put something together in the wrong order inside/behind the diaphragm


regards malcolm
curent ride
K reg BX 17TD TZD est
also own
K reg D special

no longer have
H reg CX saffari 2.5 TRI (now gone to Malaysia)
R reg xantia 1.9TD est (gone to meet its maker)
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Re: Ride height and front self-levelling

Post by andycadabra »

citronut, thanks for your logic! I may have had the problem before the leak since I recall the ride being a bit hard sometimes, but definitely had it after I tried to fix the leak by tightening the bolt. Changing the diaphragm a week later made no difference.

I tried to get some photos of the back of it - I had to put the steering on full lock to the right in order to get my hand in, then shoot looking down, 45 degree angle, from above the steering rack gaitor. I don't know if these make any sense to you!


http://i951.photobucket.com/albums/ad35 ... ad/hc1.jpg

http://i951.photobucket.com/albums/ad35 ... ad/hc2.jpg
1992 BX 17TZD 130k
1987 BX 16TRS SORN
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Re: Ride height and front self-levelling

Post by andycadabra »

looking at the diagram below, I was just thinking that assuming the height corrector operates by its central spindle being rotated by the lever on the end of it with the ball joint, then the nut at the other end which holds the diaphragm on must also rotate with the spindle, and if it were too tight and stiff, it might not be able to?

http://www.google.co.uk/imgres?imgurl=h ... BA&dur=501
1992 BX 17TZD 130k
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