Dishwasher keeps holding water after cycle

[JABA]

Periodically over the last couple years the dishwasher periodically holds water after the cycle is over. I usually run the empty water purge cycle while running a shop vac on the drain end and it will work for quite a while that way. Recently that isnt working either. Any suggestions.

Model GSD5500G00WW

[ryan111]

The piston and nut is the most common thing that will cause this.

The piston and nut is basically a one-way valve. It allows water to flow through the filter during was but it will not allow water to flow back into the washer when it is pumping out. If the piston and nut is bad water will flow back into the tub during drain.

Look in the back of the tub and you should see a filter screen. Remove the screen and you should see the piston and nut. Unscrew it and visually inspect it. There is a rubber plunger in the center and if that rubber is too small to plug the hole then the piston is bad. Below is a picture of a bad piston and nut.

This page may also help

 http://www.appliance-repair-it.com/dishwasher-not-draining.html 

[JABA]

WENT THROUGH DIAGNOSTICS ONE BY ONE. IT SEEMS MY DISHWASHER IS IN PRETTY GOOD SHAPE. THE ONLY THING I FOUND THAT MAY HAVE BEEN A PROBLEM IS A LARGE POPCORN SEED IN THE PUMP IMPELLER. YOU CAN SEE WHERE IT WAS STUCK. THE PUMP WAS TURNING JUST AT A SLOWER PACE. TOOK PUMP APART TO CLEAN OUT.  ALL SEEMS O.K. AFTER REPAIR. MY WIFE CAN BE HAPPY AGAIN.

THANKS FOR THE HELP