Since owning the car my drivers lumbar support has never held air and would deflate slowly. I finally got around to investigating the problem today and found the one way valve that is plumbed into the air line was leaking between the edges of the plastic outer and brass inner. A quick clean up and smear of epoxy and all was good.
To access the pump you need to pull the top of the seat rear panel away (fixed by xmas tree clips) which then comes away at the bottom.
The pump is located in a vinyl bag to the right of the seat inner.

No major internal seat stripping was required to remove the whole unit including the bladder.
Hope this helps someone facing a similar problem.

 

Allycat;

Thank you for sharing your experience. I have been avoiding addressing this problem in my 04XJR assuming I had to remove the entire seat and seat cover.

Please confirm before I start this work:
To access the lumbar system I pry off the back of the front seat presumably while I'm in the back seat of the car.
If I understand correctly you did not need to remove the lumbar bladder(s) in order to access the one way valve that was leaking.
I assume after exposing the system you pumped it full of air and then just listened/observed where the air was leaking?

Best Regards, William

 

Hi William, I am not familiar enough with the 04 xjr in confirming they are a similar design of seat. If they are:

1, Tilt the backrest of the seat as far forward as possible.
2, Whilst sitting in the back seat, grip the top of the rear seat panel and pull towards you.
3, Undo the retaining now visible from inside the seat panel along with disconnecting the courtesy light.
4, Pull the seat panel further rearwards then lift up to remove.

The pump assembly and one way valve is cable tied into a vinyl bag in the seat frame and can be taken out for inspection without removing the bladder by removing the cable tie and withdrawing the pump from the bag.
To diagnose my leak i removed the bladder and pump then reconnected the electrics to inflate the bladder whilst placing the non electrical parts in a water filled bowl. In addition to this I removed the one way valve and attached some screen wash pipe with cable ties to test it separately in water.

On reassembly of the valve I used small cable ties to secure all the rubber hose ends.

The bladder is held in by 2 large staples that can be removed and refitted easily.
I did find that epoxy was good for sealing the valve but will be sourcing a new one way air valve at a later date.

I have attached a picture of the rear panel of my seats in order to confirm any similarities with yours.

 

Thanks for the tip. I think using soapy water to confirm the leak might be the way to go and using the product know as GOOP would make an excellent sealer. It's malleable, clear and can be shaped with wet fingers.

 

In addition repairing the one way valve I moved the bladder up to the next bar on the mounting frame and now the support really sits in the arch of my back.

 

That's a great idea! I have never understood why the back support was down at the hips. My X308 had the support in the lower back, a perfect location.