u shouldnt get any oil through the airlines from the pumpI have an auto drain fitted and this drains into a large plastic container, when I have checked it looks like about 20% of it is oil and the rest water. The oil looks like a dark brown colour. The hydrovane puts out much more water and oil than the Mattei and they are both used for the same hours. The mattei does not put out any oil which I why I am sure this is not right.
This is my first hydrovane so I am not sure if this is normal or if it just needs a good service.