How do I stop a lubrication leak along a screw?

Background:
My aftermarket Bridgeport table (Position Wizard by Spindle Wizard)
is "special" the way some children seem to be. It uses linear rails
(rather than the more usual dovetails) to reduce friction. They then
used the original acme axis screws, but with proprietary anti-
backlash nuts. Seems to work OK as I was able to easily move my
table at 270 ipm at an acceleration of 16 in/sec sq. during testing
before lubrication. Anyhow, there is a resevoir around the crossnuts
which is desined to be filled with way oil laced with Moly additive.

Now to the problem:

When I fill the resevoir, the oil runs along the Y axis threads
through the bellows and leaks out at the micrometer dial onto the
floor (now a bucket). Any ideas how to seal this (or other ideas)
would be welcomed.

Thanks in advance,
Jeff