I have similar problems with my Xantia. In June doseur was replaced and it made a huge difference for just another 12 days or so. For longer period of time, that hyd. system just misbehaves! When I apply brake while driving car judders (not so hard as it might happen when discs are bad). Rear end usually sinks down within the hour, front end stays up for another 4 - 5 hours. After citrobics (couple of times per month) rear end stays up for 7 - 8 hours (clicking interval increases from 8 to 25 seconds) and front end sinks down within the hour. That temporarily cures the problems for day or two! While driving and when I apply brakes for stronger braking, rear end sinks! It seems to me that there is a huge internal return of LHM in system. When starting on green trafic light it is easy to produce wheelspin 'cause rear end sinks more than it should (damping?)!
I talked to serviceman today and he adviced me not to go for replacing that rubber hose that goes from HP (there is a oil dirt mark on the HP arround the suction side). He said that from his experience there is no chance to sort possible air in LHM related problems by just replacing the hose.
That hyd. related problems driving me crazy!
I'd like to sort it out, but excluding buying new HP (arround 800 EUR), FDV, regulator, etc.
Anyone with good idea?
P.S. new accumulator fitted at the end of May (clicking interval increased from 8 to 35 seconds)and, of course, after 10 - 12 days problems returned back.
Front end HC replaced 1,5 years ago, rear should be original one.
Thanks in advance for answers & comments.
Confusing problem with Xantia hydraulics
Moderator: RichardW
Akojic -
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"> talked to serviceman today and he adviced me not to go for replacing that rubber hose that goes from HP (there is a oil dirt mark on the HP arround the suction side). He said that from his experience there is no chance to sort possible air in LHM related problems by just replacing the hose <hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
That serviceman does NOT seem to understand how your Xantia is functioning [:(!]
If exactly this hose is rotten - or loose fit - or is cracked on the surface - air WILL get into your system here [B)]
To avoid further discussions - and paying lot's of money on hopeless repairs - then try replace this hose yourself [:)]
As I've written before - you may use a common PVC hose - as used for tapwater - as a shortterm repair. In fact any type rubber/plastic hose that withstands mineral-based oils can be used as permanent repair.
From a previous thread we know that this hose is ridiculous expensive from Citroen - some UK£130. You can use a lot of time for those money to find an alternative solution.
Go for it - spend a couple of hours on your Xantia this next weekend !
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"> talked to serviceman today and he adviced me not to go for replacing that rubber hose that goes from HP (there is a oil dirt mark on the HP arround the suction side). He said that from his experience there is no chance to sort possible air in LHM related problems by just replacing the hose <hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
That serviceman does NOT seem to understand how your Xantia is functioning [:(!]
If exactly this hose is rotten - or loose fit - or is cracked on the surface - air WILL get into your system here [B)]
To avoid further discussions - and paying lot's of money on hopeless repairs - then try replace this hose yourself [:)]
As I've written before - you may use a common PVC hose - as used for tapwater - as a shortterm repair. In fact any type rubber/plastic hose that withstands mineral-based oils can be used as permanent repair.
From a previous thread we know that this hose is ridiculous expensive from Citroen - some UK£130. You can use a lot of time for those money to find an alternative solution.
Go for it - spend a couple of hours on your Xantia this next weekend !
Anyway, sinking of rear (or front) end within an hour is perfectly normal for the car without anti-sink. According to manufacturer, permitted leakage of a hydraulic element is 3 ml/min. Short calculation shows me that rear end will sink within about 20 min if only ONE element, connected to rear suspension, is leaking 3 ml/min. But there are 4 of them: both hydraulic cylinders, H/C and brake valve. And, when rear end sinks a little, H/C will open, connecting almost all other elements...
Alex I entirely agree. In any event the pump output for a BX is supposed to be 4 cc per revolution. Haynes states the speed is 1/2 engine speed but I think it was Anders who provided some measurements recently and strangely the 16 valve drove the pump faster than all the others! - despite revving to in excess of 7000 rpm!
So with that output 3 ml per minute is negligible.
Akojic - I think you can only judge the performance of the hydraulics when you have eliminated all air from the system. Air leaks on the pump input are a well documented problem and as is usual with suction systems there is no leakage to the outside as a tell-tale. these things are meant to function on pure LHM which is not compressible, not an oil/air emulsion which is compressible.
jeremy
So with that output 3 ml per minute is negligible.
Akojic - I think you can only judge the performance of the hydraulics when you have eliminated all air from the system. Air leaks on the pump input are a well documented problem and as is usual with suction systems there is no leakage to the outside as a tell-tale. these things are meant to function on pure LHM which is not compressible, not an oil/air emulsion which is compressible.
jeremy
Changing the doseur means changing all or most of the LHM. New LHM or even a substantial top-up seems to hide all the faults and make the thing behave beautifully for a short while while the oil molecules get mashed up and settle into their long term state.
I had a long term problem with the warning light coming on (now cured) and used to go to great lengths not to have to top it up when working on the problem. Inevietably it seemed that whatever I'd do to it would produce an immediate apparent improvement but after a couple of days it would start misbehaving again.
It can make fault-finding very difficult.
When I had my doseur changed I also had a brake caliper swapped as the nipple broke off. The car felt so high and bouncy I had to stop, get out and have a look to make sure everything was ok (also to persuade the handbrake to adjust) After a week the warning light was coming on again and I was having to hold the steering to one side to get it to lift! - a complete waste of money!
jeremy
I had a long term problem with the warning light coming on (now cured) and used to go to great lengths not to have to top it up when working on the problem. Inevietably it seemed that whatever I'd do to it would produce an immediate apparent improvement but after a couple of days it would start misbehaving again.
It can make fault-finding very difficult.
When I had my doseur changed I also had a brake caliper swapped as the nipple broke off. The car felt so high and bouncy I had to stop, get out and have a look to make sure everything was ok (also to persuade the handbrake to adjust) After a week the warning light was coming on again and I was having to hold the steering to one side to get it to lift! - a complete waste of money!
jeremy
Jes I think thats part of it. On my BX when I get out it raises itself and then when the height corrector opens it settles to its proper height. This has therefore released some oil from the back circuits. When it drops further the height corector will open again and the accumulator will discharge next. The front being stiffer will probably keep the height corrector closed for longer. Once it opens they will equalise the pressures.
Of course if your front struts are sticky the front may stay up for a very long time as the frinction in the struts prevents the front dropping far enough to open the height corrector.
jeremy
Of course if your front struts are sticky the front may stay up for a very long time as the frinction in the struts prevents the front dropping far enough to open the height corrector.
jeremy