Washing machine?

possibly the breather is blocked.
another thing you could do is blow really hard down the water outlet to unblock any blockage, if you can't do that then attach the outlet hose to a water tap, and, with the machine in "drain" to pump the water out, turn on the tap fully and you should hear the change in the pump, when you hear this then take the outlet hose off the tap and let the pump do it's job. you may need to do this a couple of times.

Tom
November 2010