I'm taking apart the sport recaro seats
 

Has any of you done this?
Both front seats in my car have leaky lumbar support.
I've taken apart one of the seats and will be doing a leak test to see where its actually leaking from.
I can't find much info on this online so will post here and update you with my findings.
So far I've tested the air bags themselves and they are holding up just fine so the fault must be somewhere else in the system.

I took a scrap one apart to see what was in it and where the lumbar support went, but never got as far as finding where the leaks are so I'm interested to see what you find out +++

Very interested to see if you have a sensible solution to this, both my lumbars leak, but as noted in another thread a lump of foam slid behind the centre back section is a pretty good substitute. +++

My conclusions, testing but with limited access, were:
1. It's almost certainly the valve unit that's leaking. (Smaller rectangular item in your picture)
2. I can just about reach it but after looking at a dismantled seat at MJs last year decided it was a PITA job "for another day".
3. I bought a spare valve unit anyway and will try to jury-rig it in sometime. You can just about disconnect the pipework and wiring without taking the seat apart and possibly place the replacement unit lower down leaving the original in situ.
4. Taking the seat apart and especially putting it back together is not a job for an amateur!

And I too have a slowly deflating lumbar support and an interest in this +++ But sometimes i find that, with not having the knowledge, skills and specialist tools, i end up fixing the problem but having messed up the surrounding trim/fixings/other equipment!

My first ever D2 had this issue, but it was fixed by Audi under warranty so I've no idea what it actually was, and I've never had it on any D2 since - But will be interested to see the findings +++

I have the answer
 

OK, i tested every single part of the air system and found it all to be OK except for one of the outlets on the valve block, it has a little crack that quickly lets air out. My car is a 2002 so i doubt it was ever fixed.

The second pic shows the brass insert with an O ring, and the red lines show how tall the 'collars' so to speak are. Only one (the tallest one) is cracked.

I'm not gonna risk fixing that with some epoxy after taking all this time to carefully take apart the seat, i think ill look for a similar pump in other VAG models, or maybe pre fl A8 had a metail manifold on the valve block or something...
I also thought about submerging the whole thing in some sort of liquid rubber or tar and letting it set, but thats a bit extreme.
suggestions are welcome.

New replacement valve block is 204 eur on audi tradition.
I'm already thinking of adapting some generic part to do the same thing such as this, its 14.99 on ebay

Quality German plastic strikes again http://www.corradov8.com/pics/banghead.gif

Could you extend the pipework and put the pump in the seat base? Then you could epoxy it knowing that it's relatively easy to get to if it fails again.

yes that is very doable I just have to find the correct size tubing hmmm good idea.

Update:
7 series e38 valve block appears to be suspiciously similar to the audi one, except they don't seem to have the cracking issue as the inlets are completley recessed in the plastic. I bought one to try and will let you know how it goes.