[Lizard02]

My dishwasher fills and the arms work, but it won't drain. It just keeps the dirty water, fills again at rinse, and splashes around the dirty water.

I took it apart from the inside and cleaned the filters I could find, but that didn't help.

I'm thinking of pulling it out and seeing if there's anything underneath to clean.

Any suggestions?

[denman]

Here is a link to your parts
Kenmore Parts for Models 36315479000

It must be draining some because you are getting a fill.

Did you find the valve under the cover at the very back of the machine
It can cause this type of problem. Shows as a piston & nut on Page 1

Would also check the drain especially the the sink end. Make sure the fitting is clean and also the trap.

Make sure the drain/wash solenoid is pulling the flapper valve arm all the way down

[Lizard02]

I have to bail out the dirty water after it runs, and it fills up to where it's almost spilling out when I open the door. I checked the outlet hoses and pulled out the whole unit as far as I could without unhooking the electrical wires and tipped it backward to see if there was something blocking the drain behind the plastic grate at the bottom of the unit.

I took off the gratelike cover from the back of the inside of the unit, but didn't find anything. I'll check again for a piston and nut. Are you referring to page 1 of the manual that came with the dishwasher?

Someone else suggested the drain impeller. Do you think that sounds possible? (I never heard of it before.)

Thanks.

[denman]

Sorry, from your description I thought you were at least doing a partial pump out.
The redirecting flapper now becomes the most likely cause as long as the pump runs when it is supposed to drain.

The Piston and Nut assembly is on Page 1 of the link I sent you
It should unscrew so you can inspect it

I doubt it would be the impeller because you said the unit works correctly when washing.

Take a look on Page 1 on the link, at the motor
Click on the picture and you will get a number of views
If you then click on the 3RD view down you will see a flapper inside the throat of the pump housing
This flapper is controlled by the solenoid you see
It directs the water either up to the wash arms or out the drain
You should be able to manually move the solenoid's rod and flapper arm and feel the flapper change positions

The solenoid's rod must be pulled down during the drain cycle to redirect the water. NOTE: I may be back-wards here, it could be down for wash and up for drain but it has to change position and move the flapper in the pump assembly

Let the unit add some water, open the door a bit to kill power, turn timer so you are in a wash cycle, manually push the solenoid's rod down, shut the door
If it starts to drain then you are one step closer to fixing it

If the above works then either the solenoid is shot or it is not getting power