Anyway the pipe itself seems to have suffered some corrosion from the elements. Next, cue Citroen warranty who after checking with another individual said it wasn't covered due to corrosion!
After Service Manager informed me, I said this doesn't sound right as it's not a service item and the pipe should be up to spec. My cue to call the warranty dept. I was dealt with very professionally, no nonsense at all. He thought it odd that me as the customer, was ringing them directly until I explained that they had apparently refused the claim. He then checked and was very apologetic, saying that the suspension pipe was covered!
So back I toddled into the dealership and explained they would cover it.
Got a call back later to confirm that it has all been agreed and they are not mucking about, so have added the front height sensor onto the repair order too. In total a £500 bill I'm glad I'm now not paying! Booked in this Thursday.
So they've topped up the LDS fluid for me and I've driven it home. I immediately felt the difference in the ride as a result of having the fluid topped up. When I got home I did notice a large area of oil where I park, but as this is all chippings, I just assumed this was old oil from the steering rack problem that was replaced not too long ago! But looking at it closer I can see it is fresher oil.
I said I won't be using the car until Thursday, and asked whether I should depressurise the system with the Lexia to reduce the pressure in the system, but they said I shouldn't as once it is depressurised, there could be a possibility that it won't rise back up, or that repressurising it could put undue strain on the pipe!
I can't remember now which pipe it was, but it will be either 1, 3 or 4 on the diagram. So this is a new one on me, never heard of the suspension fluid pipes going on a MK 2, yet alone an X7!
So there you have it chaps, time to clean your pipes out!
Note to Vab (Vaborovic): no sarcastic comments regarding hydraulic suspension again please!
I had a front coil spring go on mine last week...... but slightly cheaper to fix at only £25 for a spring and a couple of hours work 
