Ok suspension experts:
The front now sinks to the bump stops within a couple of hours of switching off. I started noticing it sinking a bit overnight a few weeks ago, gradually this has sped up. The rear stays at normal height.
When the car is started the rear initially sinks all the way down, then after 20 seconds or so the car rises to normal height.
Is this just a failed anti-sink valve, in which case I can just accept that I've now got half a proper Citroen, or could it be something more worrying?
Xantia front sinking
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 splat</i>
Ok suspension experts:
The front now sinks to the bump stops within a couple of hours of switching off. I started noticing it sinking a bit overnight a few weeks ago, gradually this has sped up. The rear stays at normal height.
When the car is started the rear initially sinks all the way down, then after 20 seconds or so the car rises to normal height.
Is this just a failed anti-sink valve, in which case I can just accept that I've now got half a proper Citroen, or could it be something more worrying?
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
You might be able to check if the front anti-sink valve is "stuck" by the following test:
Run the car and let it lift to normal height. Switch off the motor and open the bleed screw on the pressure regulator (1/4 turn anti-clockwise) and then set the height control lever to down.
On a non-anti-sink Citroen the car should go down, on an anti-sink model the car should stay put. (No regulator pressure should cause both anti-sink valves to shut, preventing pressure being let in or out of the suspension)
If you find the front goes down while the back stays put, then yes it could be the anti-sink valve jammed, otherwise you'll need to look elsewhere - for starters, is your accumulator sphere in good condition ?
As for the back staying up overnight and then dropping suddenly after starting the motor then pumping up again, most of the feedback from people that have fixed this problem seems to be that it is caused by a nearly flat rear anti-sink sphere. (There are some recent threads about this)
Regards,
Simon
Ok suspension experts:
The front now sinks to the bump stops within a couple of hours of switching off. I started noticing it sinking a bit overnight a few weeks ago, gradually this has sped up. The rear stays at normal height.
When the car is started the rear initially sinks all the way down, then after 20 seconds or so the car rises to normal height.
Is this just a failed anti-sink valve, in which case I can just accept that I've now got half a proper Citroen, or could it be something more worrying?
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
You might be able to check if the front anti-sink valve is "stuck" by the following test:
Run the car and let it lift to normal height. Switch off the motor and open the bleed screw on the pressure regulator (1/4 turn anti-clockwise) and then set the height control lever to down.
On a non-anti-sink Citroen the car should go down, on an anti-sink model the car should stay put. (No regulator pressure should cause both anti-sink valves to shut, preventing pressure being let in or out of the suspension)
If you find the front goes down while the back stays put, then yes it could be the anti-sink valve jammed, otherwise you'll need to look elsewhere - for starters, is your accumulator sphere in good condition ?
As for the back staying up overnight and then dropping suddenly after starting the motor then pumping up again, most of the feedback from people that have fixed this problem seems to be that it is caused by a nearly flat rear anti-sink sphere. (There are some recent threads about this)
Regards,
Simon
Thanks, I'll try your test at the weekend.
As far as I am aware the accumulator is fine having been replaced a couple of months ago, although as noted in another thread it seems that the garage have actually fitted an anti-sink sphere instead of an accumulator. The concensus seemed to be that this was ok with the exception that it won't last as long as it starts out at a lower pressure.
I had wondered whether the back dropping on startup was due to pressure equalising throughout the system when the anti-sink valve opens?
As far as I am aware the accumulator is fine having been replaced a couple of months ago, although as noted in another thread it seems that the garage have actually fitted an anti-sink sphere instead of an accumulator. The concensus seemed to be that this was ok with the exception that it won't last as long as it starts out at a lower pressure.
I had wondered whether the back dropping on startup was due to pressure equalising throughout the system when the anti-sink valve opens?