A friend had that a in a house built in Arlington, VA in the early mid 70s. It got to where it would not clean anything so he took it apart and the sump was filled with broken glass. He cleaned it out and it started cleaning again. One would think that all of that broken glass would have been missed. It slowed down the water and the wash arm turned very slowly. I was not asked so I did not say anything. Of course, he used the cheapest store brand detergent so he had to rinse everything and wash rice off plates,