hi simon thanks
well all that was a week ago now ive had so many problems since im at the end of my teather well ive found out that at that time the height corrector linkage was seazed also the top link was snaped been replaced now and ive lubricated and freed it all off so thats ok now the pipes were the right way round so now i have a new problem the top link (ive left loose for the time being) while im still working on it ok well my new problem is the cars rear is eather stuck in the top position or the bottom nothing in between also if i a try to adjust the hieght no responce at all at the moment is sitting with the back end on the high setting and the front on normal and it wont budge from that setting earlyer today it was stuck on the low setting so i changed the valve back to the orginal one and after a time it rose straight to the top agian and stayed there i tried driving the car round the block no differance (after i tightend up the top link)
also if disconect the top link completly makes no differance at all still stays up there ive got to the point now where i do,nt know what else to do. or maybe there,s somthing else wrong. oh by the way i forgot to mention there,s no clicking at all from the accumilator sphere strange.
pete............................
xantia td rear height corrector help please update
Moderator: RichardW
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by pete@co.uk</i>
hi simon thanks
well all that was a week ago now ive had so many problems since im at the end of my teather well ive found out that at that time the height corrector linkage was seazed also the top link was snaped been replaced now and ive lubricated and freed it all off so thats ok now the pipes were the right way round so now i have a new problem the top link (ive left loose for the time being) while im still working on it ok well my new problem is the cars rear is eather stuck in the top position or the bottom nothing in between also if i a try to adjust the hieght no responce at all at the moment is sitting with the back end on the high setting and the front on normal and it wont budge from that setting earlyer today it was stuck on the low setting so i changed the valve back to the orginal one and after a time it rose straight to the top agian and stayed there i tried driving the car round the block no differance (after i tightend up the top link)
also if disconect the top link completly makes no differance at all still stays up there ive got to the point now where i do,nt know what else to do. or maybe there,s somthing else wrong. oh by the way i forgot to mention there,s no clicking at all from the accumilator sphere strange.
pete............................
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Boy, it sounds like you're having a bad time there.... I've never heard of so much going wrong at once. You need to go back to basics and check one thing at a time, as you have an interdependant system with feedback.
From your description it sounds like the front suspension is working just fine ? If so there is unlikely to be anything wrong with the HP supply.
I'm not sure how well you understand the system, given all the trouble you've been having, so maybe a description is in order, so you're 100% clear about what SHOULD be happening when it is working.
The height connector is a very basic hydraulic valve - the hydraulic equivalent of a single pole 3 position toggle switch, if you're familiar with electrical stuff. It has a control shaft that can move about 2mm either way from centre.
It has a small pair of springs that return it to the centre position when no force is applied to the control linkage, putting it in "neutral" or "off" condition. In this condition all three threaded pipes are isolated or cut off from each other.
The rubber/plastic hose connection is just a low pressure leakage return that catches the oil that leaks past the ends of the control rod, as the height corrector is designed to deliberately leak slightly.
It also has a very cunning little hydralic damper which consists of a large pair of washers at each end of the control shaft that try to force the leakage oil that has accumulated in the cavities at the ends through a set of small bore holes in some other washers. The oil forced through those small holes escapes through the low pressure leakage return pipe I just mentioned.
The reason for all this is that the height corrector needs to have a delay in its response otherwise it would be responding to the movement of the suspension as you drive. The damper provides about a 5 second delay, which means that it only responds to the AVERAGE height of the car, not the instantaneous height.
Pushing the control linkage one way or the other from centre requires a few seconds of sustained force before it will slowly move, which gives the delay in response needed. However when the height of the car changes its important that the height corrector can shut immediately without delay otherwise the correction would overshoot, and it does that by leaving a pocket of vacuum behind the washer so that the control rod can immediately return to the centre without restriction but not overshoot in the other direction.
Of the three threaded ports, one is a common port, (the centre pin in your toggle switch analogy) and the other two are for each end of the movement of the height corrector.
In the centre position that the spring will return the shaft to with no force applied, all 3 ports are cut off from each other. Move one way and the common port will connect to one of the other ports, move it the other way and it will connect the common to the other port. At no time will the two other ports directly connect to each other.
The common port connects to the suspension cylinders by way of a T junction, or through the hydractive unit if you have one of those. If you have an anti sink valve that complicates things a bit too, as the height corrector common port and HP inlet port are connected via that.
(See: http://citroen2.triger.com.pl/kc/pdf/citguide.pdf )
The important thing to remember is that when the antisink valve is enabled by the HP inlet pressure from the front accumulator, it just passes through the connections from the height corrector to the rest of the system as if it wasn't there.
Now you have a mechanical linkage from the rollbar to the height corrector. By clamping onto the rollbar near the middle, it automatically takes the AVERAGE of the left and right side height, so it won't respond to roll around corners. (Which would be a very bad thing....)
The important thing to realise about the control linkage is that it is a *torsion bar* and that it is deliberately able to bend. This is because the height corrector itself responds best to force and not position displacement, due to the built in damper valve.
A combination of the torsion bar springyness and the damper valve rates in the height corrector is what gives you your 5 second delay. The torsion bar is also needed because the rollbar end of the torsion bar can move a lot further across the full travel of the suspension than he height corrector can move, so it would be damaged if it didnt bend.
(The height corrector can only move about 4mm from end to end, but the total movement of the control rod over the full suspension travel without the control rod being a torsion bar would be 2 or 3 times this much)
There is a very small amount of deliberate slack in the linkage to the height corrector, usually near where the linkage connects to the height corrector. This is so that it wont try to correct very small errors in height (less than about 10mm) otherwise it would be forever making small up and down adjustments, due to friction in the suspension movement.
The slack gives you a little bit of hysteresis, which is needed for a stable feedback system anytime you have an on/off response to a negative feedback signal. (Think of a normal thermostat - the switch on temperature is higher than the switch off temperature...)
The two other ports of the height corrector connect to the HP supply inlet and the return overflow, so its a simple matter of an error in height in the down direction pushing the height corrector the right way to open the inlet port, while an error in height in the up direction opening the overflow port.
If the inlet and overflow ports are mixed up, you now have positive feedback instead of negative feedback, so you have an unstable feedback system that will "latch up" and either go fully up or fully down and stay there.
When you break down the system to its most fundamental (eg minus anti-sink valve and hydractive unit) its actually an extremely simple system.
Hope that description helps a bit.
Anyway, so if you disconnect the control linkage from the height corrector, run the engine, press the height corrector control rod on the height corrector itself manually with your thumb (remember to use car stands) one way or the other, can you get any change in height ?
If the suspension is fully down and depressurized it may take quite some time holding your thumb on it before it lifts, as quite a bit of oil has to go into the spheres and compress the gas before the car will start lifting.
The height corrector control rod only moves a very small distance, on the order of 2mm, and because it has a hydralic damper in it that prevents sudden movements from centre to one extreme, but allows it to be quickly moved back to the centre position, you have to apply pressure in one direction for 5 seconds or so before it will move and the car will respond.
You should be able to get the car to go up and down in response to your manual activation of the height corrector, if you cant, you still have a hydralic problem elsewhere and need to look for that.
If you CAN manually control the height, you either have a problem with the control linkage from roll bar to height corrector, or the manual override linkage, or still possibly mixed up pipes. (Which would make it stay right down, or right up, as mentioned in my previous response)
Regards,
Simon
hi simon thanks
well all that was a week ago now ive had so many problems since im at the end of my teather well ive found out that at that time the height corrector linkage was seazed also the top link was snaped been replaced now and ive lubricated and freed it all off so thats ok now the pipes were the right way round so now i have a new problem the top link (ive left loose for the time being) while im still working on it ok well my new problem is the cars rear is eather stuck in the top position or the bottom nothing in between also if i a try to adjust the hieght no responce at all at the moment is sitting with the back end on the high setting and the front on normal and it wont budge from that setting earlyer today it was stuck on the low setting so i changed the valve back to the orginal one and after a time it rose straight to the top agian and stayed there i tried driving the car round the block no differance (after i tightend up the top link)
also if disconect the top link completly makes no differance at all still stays up there ive got to the point now where i do,nt know what else to do. or maybe there,s somthing else wrong. oh by the way i forgot to mention there,s no clicking at all from the accumilator sphere strange.
pete............................
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Boy, it sounds like you're having a bad time there.... I've never heard of so much going wrong at once. You need to go back to basics and check one thing at a time, as you have an interdependant system with feedback.
From your description it sounds like the front suspension is working just fine ? If so there is unlikely to be anything wrong with the HP supply.
I'm not sure how well you understand the system, given all the trouble you've been having, so maybe a description is in order, so you're 100% clear about what SHOULD be happening when it is working.
The height connector is a very basic hydraulic valve - the hydraulic equivalent of a single pole 3 position toggle switch, if you're familiar with electrical stuff. It has a control shaft that can move about 2mm either way from centre.
It has a small pair of springs that return it to the centre position when no force is applied to the control linkage, putting it in "neutral" or "off" condition. In this condition all three threaded pipes are isolated or cut off from each other.
The rubber/plastic hose connection is just a low pressure leakage return that catches the oil that leaks past the ends of the control rod, as the height corrector is designed to deliberately leak slightly.
It also has a very cunning little hydralic damper which consists of a large pair of washers at each end of the control shaft that try to force the leakage oil that has accumulated in the cavities at the ends through a set of small bore holes in some other washers. The oil forced through those small holes escapes through the low pressure leakage return pipe I just mentioned.
The reason for all this is that the height corrector needs to have a delay in its response otherwise it would be responding to the movement of the suspension as you drive. The damper provides about a 5 second delay, which means that it only responds to the AVERAGE height of the car, not the instantaneous height.
Pushing the control linkage one way or the other from centre requires a few seconds of sustained force before it will slowly move, which gives the delay in response needed. However when the height of the car changes its important that the height corrector can shut immediately without delay otherwise the correction would overshoot, and it does that by leaving a pocket of vacuum behind the washer so that the control rod can immediately return to the centre without restriction but not overshoot in the other direction.
Of the three threaded ports, one is a common port, (the centre pin in your toggle switch analogy) and the other two are for each end of the movement of the height corrector.
In the centre position that the spring will return the shaft to with no force applied, all 3 ports are cut off from each other. Move one way and the common port will connect to one of the other ports, move it the other way and it will connect the common to the other port. At no time will the two other ports directly connect to each other.
The common port connects to the suspension cylinders by way of a T junction, or through the hydractive unit if you have one of those. If you have an anti sink valve that complicates things a bit too, as the height corrector common port and HP inlet port are connected via that.
(See: http://citroen2.triger.com.pl/kc/pdf/citguide.pdf )
The important thing to remember is that when the antisink valve is enabled by the HP inlet pressure from the front accumulator, it just passes through the connections from the height corrector to the rest of the system as if it wasn't there.
Now you have a mechanical linkage from the rollbar to the height corrector. By clamping onto the rollbar near the middle, it automatically takes the AVERAGE of the left and right side height, so it won't respond to roll around corners. (Which would be a very bad thing....)
The important thing to realise about the control linkage is that it is a *torsion bar* and that it is deliberately able to bend. This is because the height corrector itself responds best to force and not position displacement, due to the built in damper valve.
A combination of the torsion bar springyness and the damper valve rates in the height corrector is what gives you your 5 second delay. The torsion bar is also needed because the rollbar end of the torsion bar can move a lot further across the full travel of the suspension than he height corrector can move, so it would be damaged if it didnt bend.
(The height corrector can only move about 4mm from end to end, but the total movement of the control rod over the full suspension travel without the control rod being a torsion bar would be 2 or 3 times this much)
There is a very small amount of deliberate slack in the linkage to the height corrector, usually near where the linkage connects to the height corrector. This is so that it wont try to correct very small errors in height (less than about 10mm) otherwise it would be forever making small up and down adjustments, due to friction in the suspension movement.
The slack gives you a little bit of hysteresis, which is needed for a stable feedback system anytime you have an on/off response to a negative feedback signal. (Think of a normal thermostat - the switch on temperature is higher than the switch off temperature...)
The two other ports of the height corrector connect to the HP supply inlet and the return overflow, so its a simple matter of an error in height in the down direction pushing the height corrector the right way to open the inlet port, while an error in height in the up direction opening the overflow port.
If the inlet and overflow ports are mixed up, you now have positive feedback instead of negative feedback, so you have an unstable feedback system that will "latch up" and either go fully up or fully down and stay there.
When you break down the system to its most fundamental (eg minus anti-sink valve and hydractive unit) its actually an extremely simple system.
Hope that description helps a bit.
Anyway, so if you disconnect the control linkage from the height corrector, run the engine, press the height corrector control rod on the height corrector itself manually with your thumb (remember to use car stands) one way or the other, can you get any change in height ?
If the suspension is fully down and depressurized it may take quite some time holding your thumb on it before it lifts, as quite a bit of oil has to go into the spheres and compress the gas before the car will start lifting.
The height corrector control rod only moves a very small distance, on the order of 2mm, and because it has a hydralic damper in it that prevents sudden movements from centre to one extreme, but allows it to be quickly moved back to the centre position, you have to apply pressure in one direction for 5 seconds or so before it will move and the car will respond.
You should be able to get the car to go up and down in response to your manual activation of the height corrector, if you cant, you still have a hydralic problem elsewhere and need to look for that.
If you CAN manually control the height, you either have a problem with the control linkage from roll bar to height corrector, or the manual override linkage, or still possibly mixed up pipes. (Which would make it stay right down, or right up, as mentioned in my previous response)
Regards,
Simon
-
pete@co.uk
- Posts: 396
- Joined: 22 Jan 2005, 18:47
- Location: west midlands
- My Cars:
update guys
well ive had another go today at this and ive found out that the pipe,s where the wrong way round [:I] in fact ive had to bend the pipe,s slightly to get them to fit now the car go,s up and down as it should i messed about jacking the back of the car up of its wheels moving the height lever inside the car and i got it to go down then i then it went back to its previus rock n roll thing that is back up front down then i thought of what simon said about the toggle switch and reversed the pipes then it went right the only thing left to do now is set the height and thats not doing what its told now its ether to high or to low grrrr but ill get there in the end (i hope!)ill just try to follow what simons already told me if you have anything more to add simon or anyone please let me know, id apprecate it.
pete................................
well ive had another go today at this and ive found out that the pipe,s where the wrong way round [:I] in fact ive had to bend the pipe,s slightly to get them to fit now the car go,s up and down as it should i messed about jacking the back of the car up of its wheels moving the height lever inside the car and i got it to go down then i then it went back to its previus rock n roll thing that is back up front down then i thought of what simon said about the toggle switch and reversed the pipes then it went right the only thing left to do now is set the height and thats not doing what its told now its ether to high or to low grrrr but ill get there in the end (i hope!)ill just try to follow what simons already told me if you have anything more to add simon or anyone please let me know, id apprecate it.
pete................................
-
pete@co.uk
- Posts: 396
- Joined: 22 Jan 2005, 18:47
- Location: west midlands
- My Cars:
hi guys
update on this saga
well ive followed what simon said in his previus post and also what was said in the estate ride height post and what happens now is that i set the ride height ok so the car sits there at the correct height after sending the car to its highest setting then letting it back down again and she sits level then when i drive the car the back end goes back down agian also when i sit on the back of the car it goes down but does not raise up agian like it should yet everthing else seem to work ok any ideas the linkage was origanly seized solid and ive freed that all of ok so i can move the levers by hand so what could be going on now. oh by the way the acumilator is not making a sound could this be anything to do with it
any idea,s guys
pete.....................
update on this saga
well ive followed what simon said in his previus post and also what was said in the estate ride height post and what happens now is that i set the ride height ok so the car sits there at the correct height after sending the car to its highest setting then letting it back down again and she sits level then when i drive the car the back end goes back down agian also when i sit on the back of the car it goes down but does not raise up agian like it should yet everthing else seem to work ok any ideas the linkage was origanly seized solid and ive freed that all of ok so i can move the levers by hand so what could be going on now. oh by the way the acumilator is not making a sound could this be anything to do with it
any idea,s guys
pete.....................
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by pete@co.uk</i>
hi guys
update on this saga
well ive followed what simon said in his previus post and also what was said in the estate ride height post and what happens now is that i set the ride height ok so the car sits there at the correct height after sending the car to its highest setting then letting it back down again and she sits level then when i drive the car the back end goes back down agian also when i sit on the back of the car it goes down but does not raise up agian like it should yet everthing else seem to work ok any ideas the linkage was origanly seized solid and ive freed that all of ok so i can move the levers by hand so what could be going on now. oh by the way the acumilator is not making a sound could this be anything to do with it
any idea,s guys
pete.....................
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Hi,
Sorry for the delay replying.
Sounds like you have most of the problems sorted out now, with one remaining. So let me check I've got your current situation right:
* Manual height lever works the right way around so both front and back go up when set to up and both go down when set to down ?
* Going from manual height set to up, to to the normal position the car adjusts correctly down to the normal height ?
* If the car is a little bit too low (like you sitting on it) it wont adjust the height up a bit ? Presumably if you push the manual height lever partly (but not fully) towards the up position it will then go up a bit ?
If it is adjusting the height to the right height, but is only doing so from one direction (in this case downwards) and is very reluctant to adjust to the normal height from the other direction, it would usually be due to the manual height lever override linkage being out of adjustment.
I'm not quite sure what the linkage looks like in the Xantia, but in the GS it was pretty crude, consisting of a small plate with a hole in it attacked to the linkage going to the height corrector, and a couple of back to back tube nuts on a threaded rod such that in the normal position they are not touching, but pushing the lever to the high position would cause one of the nuts to pull on the plate. (The GS has no down setting)
I think there is also a spring in the manual height override linkage in the Xantia, right ? The main thing is, that when the manual height control is set to normal and the car is approximately at normal height, the manual linkage must NOT interfere with the movement of the control linkage between the roll bar and the height corrector. It should be pretty much isolated, so that the rollbar control rod is able to push the height corrector freely in BOTH directions.
When you set the manual height lever to any other setting, it will push against the height corrector linkage one way or the other. The 3/4 height setting pushes gently such that the height rises a little bit but not fully, (by pressing against the tension of the torsion bar mentioned earlier) while the full up and down positions apply a great deal of force to literally force the height corrector to stay in the open up or down direction pretty much regardless of the roll bar position.
It is quite normal in the 3/4 height setting for the car to be very keen to correct from a height that is too low, eg correct in the upwards direction, but unable to correct easily in the downwards direction, because the override linkage doesnt allow the height corrector linkage to move far enough in the opposing direction to correct.
This was a big problem in some older models like the GS that had no spring, I guess if the Xantia has a spring there thats why they added it, but it still doesn't entirely fix the problem, at least on my Dad's Xantia.
Anyway, if the manual linkage position is out of adjustment you'll notice a very similar effect in the normal position. (Inability to correct properly in one direction)
What happens if you get someone to hold the manual lever still in a slightly different position than one of the normal notched positions ? For example slightly towards the UP direction. If that then allows the height corrector to correct in BOTH directions when you get on and off the back of the car, you know the manual linkage is simply out of adjustment.
(Which could also be a result of the height corrector body not being mounted in quite the right place, if there is any positional adjustment, as the height corrector body mounting position would affect BOTH the rollbar adjustment and the manual height control adjustment)
Note: if it is the case that the manual override linkage is pushing one way on the height corrector a bit in the normal setting, instead of being free, then you'll probably have to readjust the rollbar clamp position again afterwards to get the normal ride height right, as the spring and the torsion bar pushing against each other will reach equilibrium at a different height.
It is possible the manual override linkage is jamming or otherwise fouling the height corrector linkage, or is even perhaps bent if things were previously siezed up. When you say the linkage was seized up before and you freed it up, did you mean only the linkage from the height corrector to the rollbar, or were you also including the manual override linkage ?
Regards,
Simon
hi guys
update on this saga
well ive followed what simon said in his previus post and also what was said in the estate ride height post and what happens now is that i set the ride height ok so the car sits there at the correct height after sending the car to its highest setting then letting it back down again and she sits level then when i drive the car the back end goes back down agian also when i sit on the back of the car it goes down but does not raise up agian like it should yet everthing else seem to work ok any ideas the linkage was origanly seized solid and ive freed that all of ok so i can move the levers by hand so what could be going on now. oh by the way the acumilator is not making a sound could this be anything to do with it
any idea,s guys
pete.....................
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Hi,
Sorry for the delay replying.
Sounds like you have most of the problems sorted out now, with one remaining. So let me check I've got your current situation right:
* Manual height lever works the right way around so both front and back go up when set to up and both go down when set to down ?
* Going from manual height set to up, to to the normal position the car adjusts correctly down to the normal height ?
* If the car is a little bit too low (like you sitting on it) it wont adjust the height up a bit ? Presumably if you push the manual height lever partly (but not fully) towards the up position it will then go up a bit ?
If it is adjusting the height to the right height, but is only doing so from one direction (in this case downwards) and is very reluctant to adjust to the normal height from the other direction, it would usually be due to the manual height lever override linkage being out of adjustment.
I'm not quite sure what the linkage looks like in the Xantia, but in the GS it was pretty crude, consisting of a small plate with a hole in it attacked to the linkage going to the height corrector, and a couple of back to back tube nuts on a threaded rod such that in the normal position they are not touching, but pushing the lever to the high position would cause one of the nuts to pull on the plate. (The GS has no down setting)
I think there is also a spring in the manual height override linkage in the Xantia, right ? The main thing is, that when the manual height control is set to normal and the car is approximately at normal height, the manual linkage must NOT interfere with the movement of the control linkage between the roll bar and the height corrector. It should be pretty much isolated, so that the rollbar control rod is able to push the height corrector freely in BOTH directions.
When you set the manual height lever to any other setting, it will push against the height corrector linkage one way or the other. The 3/4 height setting pushes gently such that the height rises a little bit but not fully, (by pressing against the tension of the torsion bar mentioned earlier) while the full up and down positions apply a great deal of force to literally force the height corrector to stay in the open up or down direction pretty much regardless of the roll bar position.
It is quite normal in the 3/4 height setting for the car to be very keen to correct from a height that is too low, eg correct in the upwards direction, but unable to correct easily in the downwards direction, because the override linkage doesnt allow the height corrector linkage to move far enough in the opposing direction to correct.
This was a big problem in some older models like the GS that had no spring, I guess if the Xantia has a spring there thats why they added it, but it still doesn't entirely fix the problem, at least on my Dad's Xantia.
Anyway, if the manual linkage position is out of adjustment you'll notice a very similar effect in the normal position. (Inability to correct properly in one direction)
What happens if you get someone to hold the manual lever still in a slightly different position than one of the normal notched positions ? For example slightly towards the UP direction. If that then allows the height corrector to correct in BOTH directions when you get on and off the back of the car, you know the manual linkage is simply out of adjustment.
(Which could also be a result of the height corrector body not being mounted in quite the right place, if there is any positional adjustment, as the height corrector body mounting position would affect BOTH the rollbar adjustment and the manual height control adjustment)
Note: if it is the case that the manual override linkage is pushing one way on the height corrector a bit in the normal setting, instead of being free, then you'll probably have to readjust the rollbar clamp position again afterwards to get the normal ride height right, as the spring and the torsion bar pushing against each other will reach equilibrium at a different height.
It is possible the manual override linkage is jamming or otherwise fouling the height corrector linkage, or is even perhaps bent if things were previously siezed up. When you say the linkage was seized up before and you freed it up, did you mean only the linkage from the height corrector to the rollbar, or were you also including the manual override linkage ?
Regards,
Simon
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Rostami</i>
Simon,
Are you an electronics/mechanics engineer?
I find a lot of control theory in your long and very enlightening answer!
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Heh, thanks [:I]
No I'm not an engineer, although I did study Electronics engineering.
I've been around Citroen's all my life (thanks to my Dad) and my first car was a GS, although I confess to owning a Japanese car right at the moment. (Please don't shoot me [:D] I'm currently looking for a Xantia, but late model Manual's are SO hard to find here in New Zealand, nearly every Xantia is an automatic, grrr)
You could say my Dad was a bit of a Citroen nut too...he was working as a motor mechanic on Citroen's in the 50's and 60's, and in fact drove the very first hydropneumatic ID19 that came into the country here and had the task of demonstrating the suspension and braking system to the local vehicle registration authorities because they refused to allow them to get a warrant of fitness because they didn't trust these new fangled hydraulic systems!!!
Needless to say, after a few demonstrations of high speed emergency braking, cornering, load carrying abilities, driving onto and off the curb without even noticing it, they had to finally conceed they were an extremely safe car and start registering them in New Zealand. [:D] (Some of the details of all this make an extremely funny but true story...)
I'm particularly facinated with they Hydraulic systems in Citroen's (after all it is their hallmark) and some of the older service manuals were really great for explaining how they worked.
I still have the original Citroen factory service manual for my GS, and compared to modern manuals like the crappy Haynes ones, it's absolutely fantastic. Very in depth explanation of HOW the systems work, not just the "take this off then put this back on" of the Haynes manual, instead, full technical drawings of all the main systems including hydraulic pump, height correctors, accumulator, suspension cylinders, suspension arms and geometry, CV and Tri-axe joints, engine, gearbox, etc.
It's actually two manuals - one that explains how everything works and gives measurements and checks to perform (such as adjust the height) and the other manual covers assembly, dissassembly, and overhauling/reconditioning.
I'll ask this in a fresh thread shortly, but does anyone know if genuine Citroen service manuals are still available for models such as the Xantia ? My Dad has the Haynes manual for his CX, and its ok, but not nearly as good as the Citroen manuals, but the Haynes manual for the Xantia is just a JOKE.
Want to adjust the ride hight ? According to the Haynes manual its "too hard" and is best left to a Citroen specialist... yeah right.... [xx(]
Regards,
Simon
Simon,
Are you an electronics/mechanics engineer?
I find a lot of control theory in your long and very enlightening answer!
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Heh, thanks [:I]
No I'm not an engineer, although I did study Electronics engineering.
I've been around Citroen's all my life (thanks to my Dad) and my first car was a GS, although I confess to owning a Japanese car right at the moment. (Please don't shoot me [:D] I'm currently looking for a Xantia, but late model Manual's are SO hard to find here in New Zealand, nearly every Xantia is an automatic, grrr)
You could say my Dad was a bit of a Citroen nut too...he was working as a motor mechanic on Citroen's in the 50's and 60's, and in fact drove the very first hydropneumatic ID19 that came into the country here and had the task of demonstrating the suspension and braking system to the local vehicle registration authorities because they refused to allow them to get a warrant of fitness because they didn't trust these new fangled hydraulic systems!!!
Needless to say, after a few demonstrations of high speed emergency braking, cornering, load carrying abilities, driving onto and off the curb without even noticing it, they had to finally conceed they were an extremely safe car and start registering them in New Zealand. [:D] (Some of the details of all this make an extremely funny but true story...)
I'm particularly facinated with they Hydraulic systems in Citroen's (after all it is their hallmark) and some of the older service manuals were really great for explaining how they worked.
I still have the original Citroen factory service manual for my GS, and compared to modern manuals like the crappy Haynes ones, it's absolutely fantastic. Very in depth explanation of HOW the systems work, not just the "take this off then put this back on" of the Haynes manual, instead, full technical drawings of all the main systems including hydraulic pump, height correctors, accumulator, suspension cylinders, suspension arms and geometry, CV and Tri-axe joints, engine, gearbox, etc.
It's actually two manuals - one that explains how everything works and gives measurements and checks to perform (such as adjust the height) and the other manual covers assembly, dissassembly, and overhauling/reconditioning.
I'll ask this in a fresh thread shortly, but does anyone know if genuine Citroen service manuals are still available for models such as the Xantia ? My Dad has the Haynes manual for his CX, and its ok, but not nearly as good as the Citroen manuals, but the Haynes manual for the Xantia is just a JOKE.
Want to adjust the ride hight ? According to the Haynes manual its "too hard" and is best left to a Citroen specialist... yeah right.... [xx(]
Regards,
Simon
yes you should be able to purchase proper cit/workshop mauals for an arm and six legs,look on ebay people have been known to sell such items on cd,and as far as haynes ref to gs/gsa hand brake lever travel they sayto firstly adjust cables at rear then shoes these modles never had drums they had discs all round regards malcolm
-
pete@co.uk
- Posts: 396
- Joined: 22 Jan 2005, 18:47
- Location: west midlands
- My Cars:
hi simon
update
thanks for all your imformation which i followed word by word now ive got everything working as it should [:D] at last like you said the h/c drum was adjusted wrong and was not centralised properly i followed what you said about the adjustment on the h/c and set it so that the car goes up and down at roughly the same speed then i knew it was right then i put the car on the highest setting put my trolley jack behind the tow bar ball got under the car losend the clamp bolt on the top link let the car down to the lowest setting jacked the car back up to the right height then set the lever inside to ride height started the car the front came up to its normal height back remained rested on the jack measured the height when i was satisfied all was correct i tightend the clamp bolt on the top link then i took the jack away at that point the car went to its lowest setting on the back then i set the height lever to low the front droped down then i sent it to the heighest setting car went stright up no problems then set it back to normal height the car came down and the back droped to where i set it then i let it go right the way down then brought it back to normal ride height the car came up and stoped to where i set it to then i sat on the edge of the boot the car went down and came back up agian to the right height by then i knew that everything was working ok [:D]. and yes you are right the height linkage has two springs one on the manual override linkage and the other on the override linkage at the top. well everthing is working just fine now just done it all tonight.
and thanks agian simon becouse i couldn,t of done all this without your help its been a right struggle for me now all is ok thanks [:)]
kind regards
write soon
all the best
pete.....................................
update
thanks for all your imformation which i followed word by word now ive got everything working as it should [:D] at last like you said the h/c drum was adjusted wrong and was not centralised properly i followed what you said about the adjustment on the h/c and set it so that the car goes up and down at roughly the same speed then i knew it was right then i put the car on the highest setting put my trolley jack behind the tow bar ball got under the car losend the clamp bolt on the top link let the car down to the lowest setting jacked the car back up to the right height then set the lever inside to ride height started the car the front came up to its normal height back remained rested on the jack measured the height when i was satisfied all was correct i tightend the clamp bolt on the top link then i took the jack away at that point the car went to its lowest setting on the back then i set the height lever to low the front droped down then i sent it to the heighest setting car went stright up no problems then set it back to normal height the car came down and the back droped to where i set it then i let it go right the way down then brought it back to normal ride height the car came up and stoped to where i set it to then i sat on the edge of the boot the car went down and came back up agian to the right height by then i knew that everything was working ok [:D]. and yes you are right the height linkage has two springs one on the manual override linkage and the other on the override linkage at the top. well everthing is working just fine now just done it all tonight.
and thanks agian simon becouse i couldn,t of done all this without your help its been a right struggle for me now all is ok thanks [:)]
kind regards
write soon
all the best
pete.....................................
Last edited by pete@co.uk on 28 Aug 2006, 23:25, edited 1 time in total.
Hi Pete,
I'm thrilled to hear you got it all sorted in the end! It sounds like you were particularly unlucky with the problems you were having, and I was beginning to wonder if you would get to the bottom of it.
The height control system is a fairly simple hydraulic servo system with feedback but if you're not familiar with how it should work when it IS working, it can be a mysterious and unfathomable black box [:D]
At least in the process you've now learnt quite a bit about how the system works so if there is a next time you'll have a pretty good idea of whats going on.
Regards,
Simon
I'm thrilled to hear you got it all sorted in the end! It sounds like you were particularly unlucky with the problems you were having, and I was beginning to wonder if you would get to the bottom of it.
The height control system is a fairly simple hydraulic servo system with feedback but if you're not familiar with how it should work when it IS working, it can be a mysterious and unfathomable black box [:D]
At least in the process you've now learnt quite a bit about how the system works so if there is a next time you'll have a pretty good idea of whats going on.
Regards,
Simon