Can you elaborate on what you mean by the last sentence? Reason for asking is that I'm hoping to swap the aftermarket air suspension on mine back to OEM before the annual meet. As such, the original compressor, valve block and associated piping haven't seen any action in two years. Just wondering if I'm likely to run into any issues.

Firstly, after 274,000 miles, the spring itself (the bladder or airbag was still pristine) I suspect the leakage was from one of the two o-oring seals.

When I assembled the new airbag and metal housing to the old damper, it is held at the top with a large threaded nut but at the bottom (behind the narrow part of the dust boot it is just an interference fit of about 5mm (tube inside a tube with an oring) and just turning the damper upside down it will slide off. That means when you jack the car up, if there is no pressure in the strut it will try and pop off (fall part) as the sping is exerting no pressure to hold itself engaged. Maybe this is worse on a new instalation with everything lubed up.

Some people have reported aftermarket springs burst soon after installation, I have a theory that they assembled it without worrying about the orientation of the bottom forks in relation to the strut and then twisted them to fit the lower control arm and in the process twisting the airbag inside.

Thanks snapdragon. That puts my mind at ease.

Sorry mannyo for hijacking your thread. Back on track again.

Thats ok.

Back to my problem,

I managed to get the basic settings done with the duff compressor although it did overheat at the end of the process as the car was increasing height from dynamic to comfort.

The rear came up fine and the front started to rise when the compressor went overheat. Result was the car went back to dynamic and the other options on the MMI greyed out. I am sure I'll get back into comfort mode once the compressor cools down, but at least all the faults have cleared and none now showing.

Compressor is cycling on/off way too often right now, it will switch on and run for 15 seconds or so, then shut off and then back on again for another 15 seconds a few minutes later. I really hope this is because of the low compressor output as it is really noisy right now and very audible in the cabin.

I did drive her yesterday in comfort mode, with the amber suspension light due to no basic settings and she sat in the office car park all day and the ride height was the same 12 hours later, so hopefully nothing is now leaking. She looks ok as the photos below show (Taken pre suspension calibration). Yes one side is slightly higher, this car park is on the **** slightly.

Next step is sort compressor, not looking forward to replacing that.

Just one quick question, does the surface used for calibration have to be completely level or just flat, eg. not on a slight slope.

Mannyo - sounds like you've had a lot of hassle there :(

For all those looking to replaces struts I bought some for my Allroad from Germany new for about £140 each. Company was called aerosus or something along those lines.

I never had any problems with it at all. I think buying a used strut is a gamble as you never know whether your used replacement is any better.

Mannyo - I had a replacement strut fitted on my D3 and it was calibrated on the flat. Not sure how a slope would affect things but why risk it?

Hope you get your car sorted. They are good cars the D3's but replacing costly items is a major headache and is where a lot of owners sell up.

if mine packs up im fitting Bilstien Coilovers

Back again, mine is now sorted and back on the road after more than 2 months.

To summarise,

It looks like the strut I replaced was not faulty, as the same issue remained after replacement. Instead it looks like the valve to the left hand rear wheel was stuck open. The left hand rear went right up to maximum, and because the valve was stuck there was not enough pressure to raise the heavy front of the car.

I have also now fitted a replacement compressor and recalibrated the suspension and she sits nice and level now.

Great news Manny, glad to see your determination has finally paid off and you have a useable D3 again +++

Well done.
Hope that everything else comes to you.