Xantia - Anti Sink Valve

[lancia58]

Hi

How can it be verified that the anti sink valve is in a good working order ? Any failure with this device ?

Thanks
Zohar

[VertVega]

if you recently have a "sinking Xantia" then it might also be caused by the leaking seals in the front struts.

[CitroJim]

Generally the anti-sink valve is one of the most reliable hydraulic components there is. Failure is very rare..

As Vert Vega says, the cause of sinking is almost always something else...

Why do you ask?

[addo]

Zohar's environment is not dissimilar to Australia in many ways - consistently quite warm and often a superfine dust in the air.

Considering the way LHM drops viscosity like a stone with temperature rises, it's not a big stretch to imagine that leakage through a valve in an always-warm climate is going to be greater than leakage through the exact same valve (per cycle count) in a milder climate.

I'm not saying it's all the reason, but you can pick a worn antisink here.

[Xaccers]

Sinking can also be caused by low pressure spheres that end of the car not providing enough pressure to shut the anti sink valve

[Mandrake]

Sinking can also be caused by low pressure spheres that end of the car not providing enough pressure to shut the anti sink valve

Can't see how Xac. The anti-sink valve is a pretty simple device. The valve closes when the pressure from the accumulator sphere is lower than the pressure currently in the suspension. The condition of the suspension spheres doesn't have much if anything to do with it.

Ironically the better the accumulator sphere the more the car will sink. A good accumulator sphere will keep the pressure from the pressure regulator higher than the suspension for longer, thus give the suspension more chance to sink before the anti-sink valves close. A poor accumulator sphere will cause the anti-sink valves to close sooner after the car is parked thus less initial height loss.

If you don't believe that, try bleeding the pressure regulator immediately after the car is parked and notice that there will be less loss of height after a few hours than normal...

[CitroJim]

It can Simon. I know it defies logic and all theory but if, and especially at the rear, the corners are flat or ruptured then the car will sink somewhat. As Xac says, I too believe it's because the anti-sink valve is prevented from sharply and positively operating under such conditions...

I've had it empirically proved several times now. Had I not then I'd have been right with you.

[lancia58]

Hi

Can a leaking pressure regulator be the cause ? Can the anti sink valve get clogged ? What is the most common reason for sinking ?

Thanks
Zohar

[Hell Razor5543]

Zohar, how many miles has the car done? In Europe Citroen recommend the LHM fluid is changed every 36,000 miles, and on the third change (108,000 miles, and every third change from then on) a hydraflush cycle is done to clean out the pipework, etc. I don't know if that would be the same where you are, but (unless somebody knows better) lets' assume so for now. My car, Gracie, is currently on a hydraflush cycle. On my BX, the LHM was black when I got it, and the hydraflush had its work cut out (but it did get everything clean).