I don't think anywhere which pumps glucose can be 100% dry, however, I would keep it as dry as possible. IMEX, if you have a lot of moisture in the air with sugars, they have a tendancy to be hygroscopic (ie absorb the water from the air). That'll generally mean it gets sticky, dirty and may make things difficult to pump.
IMO the best way to go would be to have removable catch trays which are removed and changed for clean dry ones daily, then a monthly deep clean where I'd remove all the stock (if that's possible in your system), perhaps cleaning with steam as mimimum water is used. I have used HFCS and glucose syrup in the past and not had leaks but we weren't using pallecons or drums, we were using full tankers! i think it is worth reviewing why you're getting the leaks If you're pumping out of the bottom of a pallecon, you could consider pumping out of the top then the connection isn't exposed.