How do I fix a Maytag Performa that won't completely fill?

My Maytag Performa model # PAV2000AWW will start filling with water, but once it reaches a certain point (and it seems to adjust this point lower and lower if I try different load levels) it starts draining WHILE it is filling, thus getting nothing done, the water just pours out as fast as it does in, and since it never really gets "full", it never kicks over to start agitating (the same with filling for the rinse cycle to go to spin if I move the knob past wash myself). We just got this washer used and it worked perfectly for the previous owner. If something was damaged in the move, what would it be, and how do I fix this so I can wash my clothes?