Whirlpool Dishwasher Won't Drain

[mzakal]

My Whirlpool DU1100XTPS7 seems to run as normal, but it does not drain the water out of the tub at the end of the cycle.  You can hear the sound of the motor, but nothing drains out.  I checked the drain tube, and that is clear.  I snaked my finger around in the spot where the drain hose connects to the machine, and pulled out a small chip from a dish.  I've now completely disconnected the machine and pulled it from under the counter top to get a better look.

Now I'm stuck.  I don't know what else to check, and I have no idea how to take any other parts off.  I've asked this question elsewhere, and I get links to the factory diagrams and instructions to "check XXXXX", but I can't get any guidance on how to disassemble the parts to actually see what's going on.  There aren't obvious screws holding this thing together that I've been able to figure out.  

Any guidance on what I should check and how to get there would be greatly appreciated.  Thanks.

Model DU1100XTPS7

[krazytech]

HI Mzakal,
I email you a part pic and list...the drain pump is the motor that the hose is connected to... there is a release tab you must depress then turn it CCW to remove..
after you remove it check the impeller (look like little fan blades) the blades may be broken..

[mzakal]

krazytech,

Thanks for your reply.  I removed the drain pump and took a look at the impeller.  The blades are a little nicked up, but the damage seems pretty superficial.  What I believe is the check valve (round rubber valve inside area I detached drain pump from) appears to be in good shape too.

Anything I should check next?  Is it possible that the dish chip I pulled out had lodged in the impeller blades and would prevent draining?

Thanks a million for your help so far. 

[krazytech]

The dish chip sure could stop it from draining. Also check that the impeller will spin use your finger to turn it should have some resistance but will turn .

[jumptrout51]

You can make a service test cord from an old lamp wire. Plug up to the drain pump to see if it runs.
If you drain into a garbage disposal check the connection for a grease/soap buildup.

[sc]

most whirlpool dishwashers have a second check valve in the drain hose just were the rubber ends and plastic starts. this rubber disk can get stuck closed. try a rubber hose from pump to bucket if drains slide a bent coat hanger into drain hose to push valve open.