jserb,
The stuffing tub/tube/box ought to have some kind of grease or oil in it to act as a seal. Whatever you use shouldn't be too 'thick', but should be non-soluble in water (makes sense, huh?). Lots of different opinions of whats 'best', so pick one you can live with (I like the grease used on fishing reels, comes in a 'pointy' tube which makes it easy to apply, cheap, readily available around here!). Another thing to check is the hull where the stuffing box goes through, make sure there's no leaks.
Have fun...
- 'Doc