I have a 12 year old Maytag Dishwasher DWU9202AAB which a few weeks ago I started to notice that the dishes on the top rack were not coming out a clean as "usual" which was pretty good up til now. Upon further investigation I noticed the upper arm was not spinning freely when the door was open and I was trying to move it by hand. It had some "resistance". So I unscrewed the top nut (snap outlet nut series 10 from the parts diagram downloaded from the net - see I'm not that stupid) and removed the whole upper spray arm assembly. Between the arm and the Outlet nut was "stuff" which seemed hard and caused resistance between the nut and arm. Upon cleaning it away and reassembling it, the arm rotated well both under no power and under power (Dishwasher off and on). Well after another cycle the resistance was back again. The holes in the arm are clear and not blocked at all. There was more "stuff" stuck between the Nut and the upper arm.
So now I disassemble the lower area looking for the pump housing filter. I get to it easily enough and it is relatively clean as I run vinegar through the dishwasher semi-regularly. Still I clean it out with a toothbrush. While there, I notice that the Rinse Arm Assembly (that I guess is to keep the pump housing filter clear by pushing water backwards through the pump housing filter) has some bits of plastic stuck in some of the thin slit outlets. I clean this out and reassemble the dishwasher and also clean the top arm stuff stuck between the nut and upper arm. There are no rips or tears or anything out of the ordinary looking with the filter. The filter seems to mate well enough in its top and bottom seats.
The stuff stuck in the top arm and the plastic bits in the rinse arm assy are bigger than the holes in the filter and I am wondering how they get through and stuck in between the nut and the upper arm. So now when I run the dishwasher through a cycle the upper arm at the end of the cycle has "resistance" to spinning even though it started out before the cycle with no resistance.
How is the "stuff" getting past the filter and does anybody know what causes this? It happens pretty much every cycle now!!