Lhm Leak... Fdv?, Struggling to find a fix

[jvgavila]

Hello!

Since I bought my car, back in 2002, it has leaked a bit from the FDV area. It has been always worse when car losses pressure (i.e. at night). I have found that if I leave the car parked for 10 hours at work, I get just some drops of LHM under it but when it sits overnight, I get perhaps 10x times that. All in all, I filled the LHM tank to middle of level marks (of course, with car height at maximum) about a month ago and it is already claiming for more LHM on close bents... so I guess in few days I would need to refill. About 350cm3 lost in just a month or so.

Years ago, I got an FDV from an scrappers car (luckily I did, as now there is NONE XM in any of them here ) but I have no clue if it is the same model than the one I need. Do you know if there is more than one type?. I don't recall exactly the XM model which donated the FDV... What I know is that I got same time an HP pump (which is also waiting in same box)

In case the FDV is leaking, would the problem be 'internal' (so needing FDV replacement) or just a matter of pipes going to it?. My trusty Citroen mechanic told me some years ago that it was an 'internal leak', which had me puzzled.

Regards,

JOSE

[jorgy9]

Hi Jose -and welcome to club-xm (remember of u know u from XML!)-

Don't know about the variety of FDV models.

What to do if yours leaks: u don't even need another one (and the one from a scrapyard could be in a worse state than yours). As u r using your XM not as ur everyday car (if I'm right), I guess u can take the FDV off car and overhaul it. For this, u need the special kit from Cit (part No anyone???). It includes some tiny filters and seals, if I'm not wrong.

Just take to bits yours (not difficult), clean, and replace with those new parts.

Then u will need to retune the pressure. There are a couple of nuts on the FDV's body; one of them is setting the pressure that goes to the steering assistance. This needs to be 120 bar by Cit specification, if I remember well. As I guess u will not have a gauge to measure this, just re-adjust it empirically to a point where steering assitance is satisfactory and works at all instances.

BTW, ur FDV leak, could be due, well, is probably partially due, to it being internally sludged and blocked. This is why it's a great idea to put your XM on hydraflush as a matter of course -if u have never done so-. This is specified by Cit as necessary maintenance every 100,000 kilometers. Few garages practice it, and then the leaks start, together with lowering performance of anything hydraulic.

Personally I would first put the XM on hydraflush and run it and see. Mine had various small (external) leaks when I bought it at 222.222km and was loosing, like yours, about 0.5lt/month; after 1.500km of hydraflush they have all stopped (just the system was so totally blocked that pressure was escaping outside rather than passing where it should).

cheers
George

[DerekW]

I think the FDV is the same for all cars which have it. With the introduction of the 6+2 pump and anti-sink, the FDV became obsolete. This may explain why they're becoming hard to find.

Derek