[ainarssems]

Originally Posted by steamship

Now you've identified the problem, the part number is 4E0955687 for the shaft seals. Costs around £13 from the dealer and it includes a filter in it.

I think that's the seal between pump and reservoir, I don't think you can buy the shaft seal on it's own. I had similar problem on A6, just bought the whole pump from local motor parts direct shop for about £6, it's been couple of years and it's still working fine. It was a dual output pump for estate, single output for saloon was even cheaper.