My First Car - Y3 2.1TD

[Mitki4a]

The only item that can affect the steering like this is the FDV (flow distribution valve), which diverts pressurised fluid either to the suspension/brakes, or the steering system.
High pressure, low flow to the suspension/brakes, low pressure, high flow to the steering.

Your last picture shows the FDV very clearly.

It's unlikely, but possible that the FDV has a stuck, or sticky shuttle, but that seems unlikely as you seem to be suffering loss of pressure to both systems. If the main system pressure drops try turning the steering a little as that should cause the shuttles to move and may rectify the fault.

The fault still appears like air entrained in the hydrauklic fluid. Try tightening the hose clamps a little, also check the suction pipe and spigot on the LHM tank.

Have you checked the 12mm pressure reief bolt on the regulator is tight?

On another note, I noticed your car has a peugeot gear knob fitted. You can still obtain the correct one from a citroen dealer. p/n 2403 E0

Yes the gear knob is bugging me a lot too
I should find someone breaking an xm for spares and go on a shopping spree.

I wasn't sure where exactly the regulator is. Couldn't find an exact diagram online. Is it accessible from top or I have to lift the car up?

[White Exec]

Someone else's engine bay!? You should have said!

LHM float
Just checked mine here. The rectangular plastic base turns about 30deg anticlockwise, comes against a stop, and then lifts out.
When swung into the release position, the rectangular base almost touches the side of the filler neck. Your photo shows it in the locked position.
You will need to remove the rubber breather cap to allow it to lift out.

The LHM looks wrong colour, despite not being particularly dirty. Should be transparent fluorescent pale green, and quite watery.
Check against some new stuff.

[DownUnderXM]

Great detective work, and great photos!

However I haven't a clue what your first photo in your most recent post is showing. I am pretty certain it has nothing to do with the hydraulic system - it might be to do with vacuum.

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Sorry it does look confusing. There it is.

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Oops!! In my defence it was late at night my time. Also the hydraulic pump on my V6 (petrol) Xm is so hidden that I can't actually see the rear of it!

Whie Exec and Diesleman have certainly given very good advice. Hopefully there is nothing wrong that can't be easily fixed.

I must say, your car looks to be in fantastic condition - no wonder you bought it. The 'wetness' on top of the LHM tank is to be expected if the tank is overfilled.

Re. the LHM. Yours has certainly lost it's green colour, but I have noticed that it seems to turn yellow with age (maybe more so in hotter climates? Don't know). There is an advantage in this - as part of the process of changing the fluid, you should bleed the brakes. If you use a clear tube from the bleed nipple, you will easily see when the new fluid has pushed out the last of the old fluid because of the colour change.

Re. White Exec's suggestion of using hydraurincage to cleanse the system - if Diesleman is right about the flow divider valve, then the cleaning fluid should gradually free up the sticking valve. I would definitely remove the LHM tank so that you can clean it out properly, but obviously be very careful with all the rubber hoses connected to it. All your hoses look great in the photos, but they get brittle with age. To keep any hydraulic Citroen running long term, at some point it becomes necessary to replace all those rubber return lines.

Don't worry about the little bit of seepage around the flow divider valve. As to where air can get in, remember that it is only the suction line that has "negative" pressure which can draw air in - all other lines are under pressure, so LHM gets pushed out if there is a minor leak, but air cannot get in.

[Dieselman]

Great detective work, and great photos!

However I haven't a clue what your first photo in your most recent post is showing. Your pump should look like this:

hydraulic pump.jpg

For reference, the first pic was indeed the hydraulic pump, the pump you have shown is for a car fitted with anti-sink, only fitted to later Xm.
The early pump has 7 pumping elements and a single outlet, with high/low pressure flows being controlled by the FDV.
The later pump has 6 low pressure- high flow, pumping elements and two, high pressure- low flow, elements, feeding two separate outlets.
There is no FDV required for a split pumped system.

[DownUnderXM]

Thanks - I've never seen an early pump.

[Dieselman]

I wasn't sure where exactly the regulator is. Couldn't find an exact diagram online. Is it accessible from top or I have to lift the car up?

The pressure regulator is the item mounted on the front of the gearbox, with the sphere screwed into the top of it.
It is to the right of the FDV in you last picture.

You can just get to the 12mm relief bolt from above, but its easier from under the car.

WARNING:
Never go under a hydraulically suspended Citroen without supports or ramps being in place.
The car can lower at alarming speed and goes very low...you could be crushed.

[Mitki4a]

I jacked the car up and took a look at the relief bolt. It actually wasn't very tightly screwed in and I did 2-3 more quarter turns. I might be wrong but I think it did feel better on the short drive back home. Didn't get any pressure warnings and steering seems to be ok with only occasionally slightly getting heavier for 1-2sec (would probably need to properly bleed the system from any left over air). Will be watching it closely.


I checked over the rubber mounts and I'm not too sure what to make of it.
They don't look to be bent out of shape but rubber has small cracks from age I guess.
Changing them would definitely give me some peace of mind. Are replacements hard to get and how much would they cost?

[White Exec]

If you were able to tighten the 12mm pressure relief bolt by 3/4 of a turn, then it wasn't properly closed, and pressure would have been leaking away. Normally, just one complete turn is enough to release all pressure, and allow the pump (if run) to simply pump back to the reservoir instead of pressurising the system. (The bolt is not to be removed, in case a sealing ball under it falls out.)

The strut head rubber looks split, and you ought to get the strut heads re-rubbered before any damage occurs.
New strut heads are unobtainable now, but ones with the steel in one piece can be rebuilt with new polyurethane.
Search on here for Elastomer.eu, or go to their website for details.
They are in Kaunas, Lithuania (EU), and do a good job. Lots of us have used them.

Details are also on the forum for strut-top removal and refitting, and replacement of the two strut-top O-rings.

[xmexclusive]

The type of failure visible on the underside of those strut heads is defined as axial tearing.
If you read the strut head guide in the self help section you will see that is one of the more serious failure modes.
If left it will fairly quickly lead to a sudden failure.
There is a well formed crack in the rubber that is growing vertically.
There is nothing other than rubber directly above that crack.
Good few photos on here of struts having bent up the bonnet of an XM.

[Mitki4a]

Thanks for the info guys. I'll have it in the shop next month and will see what we can do, perhaps also change out the fluid.
Btw even on high the spheres still have almost a finger-sized gap from the scuttle. I guess when it goes in the end it would go quite quickly.