Anti sink valve.

Rich · Post by **Rich** » 19 Apr 2005, 01:45

Hello everyone, at the weekend i did a sphere change and a service on my dads Xantia, (rides like a proper magic carpet now!)[:D][^] It's a W reg 2000 model HDi SX 110. While taking a good look around under the car i noticed that the front anti sink valve, the one under the LHM reservoir has a slight leak. It's not really bad, it just kind of steadily drips. I just wondered if anyone could tell me if they are repairable (new seals/O rings etc.) Or should i just bin it and buy a new one from our friends at GSF?
Many thanks, Rich.
'00 Xantia Exclusive HDi
'04 BMW F650 GS Dakar.

BX-Basis · Post by **BX-Basis** » 19 Apr 2005, 02:27

You can simply unscrew the cap on the front end of the valve and install a new O-ring. Unfortunately, this way is the unofficial way, officially the valve is not repairable and needs to be replaced by a new one. In the Citroën microfiches you won't find the O-ring needed to repair it, although there is an original Cit O-ring that exactly fits. I can try to figure out the spare part number tomorrow (if I don't forget...) at work. We have sealed a lot of anti-sink-valves already...

Hans · Post by **Hans** » 19 Apr 2005, 17:04

Is it also possible to fix the part in the valve itself that stops the sinking? Leaking internally?

JohnD · Post by **JohnD** » 19 Apr 2005, 23:20

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Rich</i>
While taking a good look around under the car i noticed that the front anti sink valve, the one under the LHM reservoir has a slight leak.
'00 Xantia Exclusive HDi
'04 BMW F650 GS Dakar.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Treat it as an emergency. When I was in Spain during January, I had a slight leak from my front anti-sink valve. Just the occassional drip. After a few days, suddenly within minutes, the reservoir emptied itself under the car. As a precaution against future trouble, I've replaced the rear one only this morning. If you get one from GSF, don't forget to order five pipe seals as well.

JohnD · Post by **JohnD** » 20 Apr 2005, 00:33

Here's a picture of an antisink valve dismantled

This is it on the rear of the car

Niek · Post by **Niek** » 20 Apr 2005, 03:06

That's neat, I have a 'sticky' front one I think. The front sinks but the rear stays up (an inverted bx I suppose). I had the valve out once to clean it but couldn't figure out how to open it, I guess I should have tried harder... This certainly helps (now I have to get bak under there and take it back out though. Oh no wait I have to get underneath there anyway to fix the leaking HC and fix the exhaust from rattling against something...[B)])

Post by **c.morewood** » 18 Oct 2005, 19:37

I've just bought an antisink valve as my rear one is leaking and I didn't fancy a massive failure as JohnD had.
Is it a messy business to change?
With the car up on ramps, no pit to work from, and after depressurising the system, am I likely to get a facefull of LHM or will the fluid just drip out?
Anything else I should watch out for?
Thanks
Chris

JohnD · Post by **JohnD** » 18 Oct 2005, 22:26

It's an easy job to do providing you've got ramps. You'll catch a few drops on your face but no sudden deluge. Watch out for the seals being left behind in the old valve although they recomend fitting new ones.

JohnD · Post by **JohnD** » 19 Oct 2005, 10:12

Here's the picture of the rear antisink

and this is the exploded view

Post by **c.morewood** » 20 Oct 2005, 19:07

Thanks John,
Tried to replace the valve today but one of the connections is so tight I can't get it to move ... so rather than damage it .. I'll take it along my local independant garage.
Chris

JohnD · Post by **JohnD** » 20 Oct 2005, 20:44

It would help to give the union nut a few sharp taps, end on, with a square drift. Also use a flange nut spanner - not an open-ended one.