Hi all (again)
Xantia been in for wheel alignment and guy said I had 5000+ miles left in my brake pads. (I'd been assuming poor braking performance due to them being near end of their shelf life, wrong again).
The suspension is doing odd things (all 5 spheres changed, not anti-sink though). The car will sink sometimes when parked up. Sometimes in a short time, sometimes takes ages, sometimes doesn't sink at all. I was in a carpark, went to start car and the front dropped 'voom' straight to lowest setting then came back up. Gave me the wiggins.
While the car was up on the ramp we had a look under it, can't see any leaks from spheres or pipes. Is this behaviour and poor braking power due to worn brake valve, or could there be another cause?
Help appreciated as always...
Mike
Doseur valve and sinking suspension
Moderator: RichardW
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tomsheppard
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BX owner here, so not all I can say comes from direct experience (no anti-sink).
When was the lhm and/or the anti-sink sphere last changed? If you have dirty lhm, the height correctors are unlikely to react quite as designed as they have very fine tolerances (like most of the hydraulic components). Filters must also be inspected/cleaned if lhm is to be replaced. Lhm is best changed approximately every 3 years/30k miles, as over time it becomes dirty, losing the brilliant green colour of fresh lhm.
I'm not sure exactly what symptoms occur with anti-sink sphere problems, but I seem to recall from another post here that they can cause some sudden and unpredictable changes in ride height, particularly on startup.
Also, if height corrector linkages are seized, or height-corrector links to rollbars have become slightly displaced or loose, that's another potential cause of problems. Does the car respond correctly to height lever movements? Stiffness in the height corrector lever is a sign that linkage pivots are seized or are only moving through restricted travel, or that the linkage has jumped out of one of the guides en route. Freeing-up/lubricating the pivots, adjusting the height correctors and other such work is best done fom a pit, if available, as small height corrector inputs can make the car sink/raise very suddenly and dangerously for anyone working underneath, as you've already discovered.
Step-by-step diagnosis is vital here, as in most hydraulic issues.
David
When was the lhm and/or the anti-sink sphere last changed? If you have dirty lhm, the height correctors are unlikely to react quite as designed as they have very fine tolerances (like most of the hydraulic components). Filters must also be inspected/cleaned if lhm is to be replaced. Lhm is best changed approximately every 3 years/30k miles, as over time it becomes dirty, losing the brilliant green colour of fresh lhm.
I'm not sure exactly what symptoms occur with anti-sink sphere problems, but I seem to recall from another post here that they can cause some sudden and unpredictable changes in ride height, particularly on startup.
Also, if height corrector linkages are seized, or height-corrector links to rollbars have become slightly displaced or loose, that's another potential cause of problems. Does the car respond correctly to height lever movements? Stiffness in the height corrector lever is a sign that linkage pivots are seized or are only moving through restricted travel, or that the linkage has jumped out of one of the guides en route. Freeing-up/lubricating the pivots, adjusting the height correctors and other such work is best done fom a pit, if available, as small height corrector inputs can make the car sink/raise very suddenly and dangerously for anyone working underneath, as you've already discovered.
Step-by-step diagnosis is vital here, as in most hydraulic issues.
David
Only had the car a couple of months, slowly curing niggles.
LHM looked a bit orangey (i.e. rusty, not vivid hydraflush colour). Its on my list of things to do.
Car responds to height changes fine, brakes are functional but I brake probably twice as far away from things than I do in the other half's punto (no ABS on either vehicle).
I was just shocked when the front just dropped on starting the car, its done it two or three times now.
I'll get hold of some hydraflush and give that a whizz through, see if things improve.
LHM looked a bit orangey (i.e. rusty, not vivid hydraflush colour). Its on my list of things to do.
Car responds to height changes fine, brakes are functional but I brake probably twice as far away from things than I do in the other half's punto (no ABS on either vehicle).
I was just shocked when the front just dropped on starting the car, its done it two or three times now.
I'll get hold of some hydraflush and give that a whizz through, see if things improve.
Here's some pics I took of LHM (before & after) which should give you an idea of what LHM *should* look like as opposed to what it usually does, particularly in a garage serviced or maintenance starved Cit.
The reason I say "garage serviced" is that owners not very "car savvy" tend to take their cars in for 'an oil change & service' and forget (or don't realise)this stuff needs routine changing unlike the antiquated standard systems. [:0]
If the garage just does what he's told, he doesn't question it and if he's a bit scared of Cit hydraulics, he really doesn't want to know anything that could complicate his planned days activities. [:D]
http://www.aussiefrogs.com/snippets/lhm_story.htm
As regards your problem, I have often said there are possibly more good doseur valves changed than faulty ones. Any leak in any part of the system will cause some of these symptoms. I recently had a problem on a BX where the car firstly wouldn't sink & then after I adjusted the suspension height, wouldn't rise; at this stage, it would fall almost as I got out of the car. It turned out to be the adjustment that runs front to back, not the ones on the actual stabiliser bars. An arm was touching the edge of the plate it sits in and when parked on a certain angle, basically told the suspension to lower.[;)]
As the car is a recent aquisition, it may pay to just do a fluid change & filter clean as well as a general check on suspension adjustments and fit new jubillee clips to the hoses on the tank etc before starting to spend up on doseurs etc.
Alan S
Alan S
The reason I say "garage serviced" is that owners not very "car savvy" tend to take their cars in for 'an oil change & service' and forget (or don't realise)this stuff needs routine changing unlike the antiquated standard systems. [:0]
If the garage just does what he's told, he doesn't question it and if he's a bit scared of Cit hydraulics, he really doesn't want to know anything that could complicate his planned days activities. [:D]
http://www.aussiefrogs.com/snippets/lhm_story.htm
As regards your problem, I have often said there are possibly more good doseur valves changed than faulty ones. Any leak in any part of the system will cause some of these symptoms. I recently had a problem on a BX where the car firstly wouldn't sink & then after I adjusted the suspension height, wouldn't rise; at this stage, it would fall almost as I got out of the car. It turned out to be the adjustment that runs front to back, not the ones on the actual stabiliser bars. An arm was touching the edge of the plate it sits in and when parked on a certain angle, basically told the suspension to lower.[;)]
As the car is a recent aquisition, it may pay to just do a fluid change & filter clean as well as a general check on suspension adjustments and fit new jubillee clips to the hoses on the tank etc before starting to spend up on doseurs etc.
Alan S
Alan S