Simon: There will be residual water standing in the tub hose and pump. If you do see any standing water in the basket and it completed the cycle, it will be normal for water to run out when twisting the drain pump filter cap off. If you have wet/dry vacuum, attach the end of the vacuum hose to the end of the drain hose it should draw most to the residual water out. Have a shallow pan and an old towel to soak up any water that may leak out. Be sure to disconnect the power cord from the power source before servicing. Before re-installing the drain pump clean out cap, wipe the seal clean of any debris and the mating surface on the pump before installing the cap.