A copy:

This model is equipped with a soil settler system. The inlet to the soil settler funnel is located to the
right and just behind the lower spray arm assembly.
Since this inlet is located in an area that is relatively free of water turbulence, food particles washed
from the dishes can collect in this area and fall through the funnel and accumulate in the collector. Food particles continue to collect as long as the dishwasher is in the Wash mode.
When the Wash cycle is finished, the dishwasher will reverse the direction of the motor and enter the
Drain mode. Water is pumped into the port at the bottom of the soil collector during the Drain cycle
causing the ball in the collector to rise against the opening in the bottom of the funnel. Water flows
through and out of the collector through the top port and into the drain line. Food particles
collected during the Wash cycle are carried out with the drain water. When the Drain cycle ends and
the pump stops running, the ball settles to the bottom of the collector.

Removing the Soil Settler Assembly
1. Disconnect the dishwasher from the household electrical system and lay the unit on its back.
2. Remove the four (4) Hex-head screws securing the soil settler assembly to the tub.
3. Disconnect the two (2) hoses from the soil settler collector.
4. Remove the funnel and funnel grate, check valve ball and seal from the soil settler collector.

And can food particles and other be the cause for the low draining capacity?
Sure.

jeff.