is my topsider working?

[sixto]

I tried my Topsider for the first time yesterday. I believe I followed all the instructions. I couldn't get more than a cup out of 40 pumps. The stub on the can that the hose attaches to is loose such that I can hear air leaking unless I bear down on it. It also helped when I smeared grease around where the stub fits its flange. I presume this looseness is why it won't draw oil long enough to drain the sump in one go.

Could someone please confirm that the fitting isn't right or suggest what I might be doing wrong?

Thanks,
Sixto
78 450SEL
91 300SE