Kitchenaid kd-21 water coming out spray nozels but nozels not spinning

[rlrobian]

Hi, new to site looking for help.
    I have a 20+ year old kitchenaid kdi-21ad dishwasher.  Installed in new, about 25 years ago.  Lately it's developed an problem.  The spray nozels do not spin.  Water is comming out and the bottom one squirts to the roof of the machine.  Not as sure about the top but when I open the door during a wash cycle I see water dripping out.  I've juriey rigged the limit switch to watch the unit run, got a little wet in the process, but neither of the nozzels are spinning.  They turn by hand nice and easy.  I;ve cleaned the filters under the bottom nozzel, was pretty well blocked, but is clear now. 
What causes the nozzels to spin?
Why would water come out but not spin???
Thanks
RL

[theoldstoveguy]

Make sure the holes on the bottom of the lower wash arm are clear,they flush out the filter. I have seen a lot of wash arm bearings get plugged up .Try cleaning them and the wash tower shafts.

[jumptrout51]

When the machine drains does it pump the water out completely and quickly?

[rlrobian]

Thanks for the quick reply.  The top and bottom wash arms are clear.  They do have a bit of buildup coating the inside of the arms but the water flow is open and free.  Water comes out the jets when it is running, but the arms do not spin. 
The pump empties the tub just like it has for years, fast and complete. 
Is it possible that not enough water is comming through the pump.  The water coming out of the bottom arm doesn't squirt to the top of the unit.  The water coming out of the top unit is hardly more than a trickle. 
Could I have a clogged water flow somewhere in the system?  I have had the unit apart over the years and there is a small triangular piece of plastic that I can't find in any diagram that is missing in my pump assembly.  Could that be the cause??
Thanks guys.
RL

[rlrobian]

In the diagram for the wash and drain pump the missing piece is numbered 10-11.  But according to the description and names on the parts list I think there is a misstake.  The piece is just a small plastic plate.  I have no idea what it used to do.

[tgoods]

What I see a lot on these vintage Kitchenaids is the upper and lower pump housings warp.  This causes a gap and it loses water pressure to the spray arms.  Unfortunately, the parts are no longer available.

[jumptrout51]

You need to replace your pump impeller.

[rlrobian]

Removed the impeller.  Quess what I found, the small plastic piece I was trying to describe earlier in the email thread.  It has been considerably damaged after a few million revolutions in the impeller.  But I was able to remove the remains of the part from the impeller.  Reassembled and the unit is working much better, not perfect but definitly better.  The lower arm is revolving and the spray is stronger, however the top unit is still not turning.  I have removed the plastic connecting tube between the top unit and the port coming out of the back of the unit.  This hose has had several splits along the bottom that I have repaired in the past but currently it is still sealed up fine. 
   
Is the gasket between the two lower pump housing parts still available. If not has anyone fabricated one out of gasket stock?

[rlrobian]

Where can I get a repair manual and a parts manual for this unit? 

[jumptrout51]

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