I too have a water cooled/lubricated stern tube, but not sure of its make. Engine is Barras Shire in a 57' East-West hull. In general I think the arrangement is much better than the traditional gear and for over 500hours there was never a drop of water in the bilge. However, last year on the Rochdale I picked up a load of fishing line and plastic sheet, first sign was squealing from the shaft so I stopped right away. Cleared it but since then the seal has leaked about half a litre every 4-6hours (depending on revs). Last week we had a four & half hour slog up the tidal Trent at 2000rpm and now she's letting in about 3-litres an hour. 1000 hours on the boat now, from other correspondence this seems a bit low for these seals - any thoughts? Also, I'm certain that the water enters through the strern tube, and returns to the weed hatch, not the other way round. Only way I can see of changing the seal is to take the shaft out.