Whirlpool Dishwasher DU920PWKT0 not draining

[domr]

I am trying to fix a Whirlpool Dishwasher  DU920PWKT0  that is not draining completely.  When it is going through the drain cycle it goes from a stream to a trickle and stops before emptying.  I can get the water out by cycling it into the drain cycle 2 or 3 times.  I found pieces of a waxy label stuck in the drain grill at the bottom of the washer so I suspect the rest of it is hiding somewhere.  This is far as I can disassemble it?  Any hints on how to go farther or is a sealed unit?  I would think I could get under the filter screen somehow?

 

[AccApp]

Look under the tub. Attached to the drain hose and sump is a check valve, #15 in the drawing. I'll bet you have something stuck in there. This older model uses the main wash pump as the drain motor by reversing it.

[domr]

Thanks for the reply.  This really helps.  Looks like I might have to pull the unit to get to the drain hose.. I was hoping I could get it from the top.

[Chat_in_FL]

2 hours ago, AccApp said:

Look under the tub. Attached to the drain hose and sump is a check valve, #15 in the drawing. I'll bet you have something stuck in there. This older model uses the main wash pump as the drain motor by reversing it.

 

57 minutes ago, domr said:

Thanks for the reply.  This really helps.  Looks like I might have to pull the unit to get to the drain hose.. I was hoping I could get it from the top.

You can access the check valve #15 by removing the toe panel, no need to pull out the whole dishwasher....

Edited November 27, 2017 by Chat_in_FL

[domr]

Well, I removed the check valve and could not find anything inside the valve.  I poked around the hole and it seems clear.  The drain hose is clear.  I did a blow test on the valve and it does leak.  I also noticed that it was sucking air during the wash cycle.  Could the check valve be causing it to leave the tub almost full?  I would figure that would only stop the hose water from draining back.  Since it seems to be pumping intermittently could this be a pump issue?  It seems to be working fine when washing but it does not seem to be pumping consistently when draining. 

[Chat_in_FL]

Item #24 is the drain impeller and seal. If you can get at it and have a look, fine. But note that I've found that it tends to seize onto the motor shaft due to corrosion, which means a new motor assembly #17. 

If you can access the drain impeller, and find you need to replace it:

Part number: 8193525

[MoTeD]

The filter comes off by way of removing all the torx screws on top. There are a couple layers of dissassembly that will allow you to clean the inside of the pump housing.