Citroen Xantia possible LHM leak

[CitroJim]

So i just need to remove the LHM tank. No other parts to be removed? Are there any cautions that i need to be aware when removing the tank? Any special tools?

It's good to use the special pliers for unclipping the hose clips on the tank filter head but a pare of medium-sized wire-cutter pliers can be used if you cannot obtain the proper clip tool.

The special tool allows the clips to be easily re-used too...

This is an example of the tool.

http://www.lasertools.co.uk/product/3397

Apart from that, no other special tools needed.

Set the suspension on low before removing the tank and be aware it will be heavy as it'll have getting on for four litres of LHM in it

[xantos]

http://xantia007.free.fr/05_doseur_tuto.php

Quite useful link... It's in French but use Google Translate you should be ok...

Note that it really often happens that you split the return pipe.

[Dusan2222]

Thank you for your efforts. Just noticed that the rear of my xantia drops (sinks) after engine start. Could the reason be also the dosseur valve?

[Hell Razor5543]

Thank you for your efforts. Just noticed that the rear of my xantia drops (sinks) after engine start. Could the reason be also the dosseur valve?

I would say that it is possible the reason she sinks (after the engine start) is due to a leaking dosseur valve. The rear brakes are fed (to some degree) from the rear suspension (which is why it is recommended to have some heavy weight in the boot when MoTing her, as otherwise the Xantia may fail due to insufficient rear braking force). Once the engine is running, and the LHM pressure goes up enough, the anti sink valve opens. If there is low pressure on the other side the pressure to the rear suspension would drop slightly (until it equalised), so the back end would also drop slightly.

However, saying all that, the valves (due to their age) will all have some slight internal leakage, so it will take a few moments longer for the pressure to come up to operational normal than when the car was new.

[Dusan2222]

Okay people, i did change the rubber cap which i bought from ebay. The valve seems to operate okay now (i cannot notice any leaks). But the rear sinking has remained. What could be the reason?

[CitroJim]

I have known ruptured (punctured diaphragm) rear spheres be the cause of this kind of sinking in the past...

[Dusan2222]

I did one experiment. I started the car after she was staying still for a day. Before i turned the engine on, i floored the brake pedal couple of times. I noticed that the rear sinks to the full service position, and the it raises up. Next day, also i left the car not driven for a day, i turned the engine without pressing the brake pedal. The car sinked again, but noticably less. Then it raised up again. Any thoughts?