C5 X7 3.0 Hdi Power Steering Stiffness Regulation Valve

[IGriffen]

Hi everyone,
My power steering has completely stopped working. For a few months now it's not worked when the engine was at idle but when revved it started working.
I replaced the belt, then the pump but no change. I've also checked the fluid level and there are no leaks.
It stopped working all of a sudden while driving. Luckily I was on my way home and managed to wrestle it back.
I'm aware that there is a stiffness regulation valve that controls the steering stiffness depending on speed. I think this might be the problem as before it stopped working the steering weight was very inconsistent. Sometimes it would feel very light when on the motorway and other times feel quite stiff.
Does anyone know where the valve is located please? I've had a look but I can barely see the rack and can't see anything on the pipe work apart from this in the picture below but this looks like some sort of sensor.
Thanks in advance
Ian

[GiveMeABreak]

I don't think the 3.0 which has the coupled pump has any such valve - it looks to be controlled from the pump itself. However you may want to try this official procedure for bleeding the system which differs slightly from X7s with Electro-Pump assembly and hydraulic suspension.

• Start the engine, with the wheels straight ahead without touching the steering wheel.
• Wait for the vehicle height to stabilise.
• Work the steering slowly, going from lock to lock in both directions, about ten times.
• Stop the engine.
• Top up the power steering fluid to the maximum level "b".
• Carry out a road test and check the level of power steering fluid (With the engine stopped, and the cap screwed on, oil temperature 30°C).