If it turns out to be the EHA itself that is leaking and you want a good used one I have the one I pulled from my 560SL which I would sell for some nominal sum...but check the o-rings first, I would bet that is where your leak is coming from...did you change them when you replaced it last time or just re-used the old ones? I think my new one came with new rings but I know I used new ones when I replaced mine...I never re-use o-rings.

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz