This is mostly to satisfy my curiosity - we've just had a Bosh integrated dishwasher installed and the pump bit that connects to the water supply has a sort of clear plastic housing and I can see black liquid inside. After the installation it looked as if a little of this had sprayed out - I cleaned it up, but just wonder if everything is OK, and what is the purpose of that liquid? Thanks for any insight. The dishwasher seems to be working fine so far.