Ice clumps in the tray so I assumed I have a leak.
I replaced the water valve but this did not correct the problem. I also decreased the water volume although this had not previously been a problem. Can it be a problem with the icemaker itself and if so how can I diagnose it?
Here are your parts.
http://www.appliancepartspros.com/partsearch/modelsearch.aspx?model=mfd2561hes
I am assuming that the clumps are in the ice storage pan (Item 12 in Section 9).
Take some ice cubes and put them in a dish in the freezer for a couple days.
If they clump together then the problem is not with the ice maker but with the freezer temperature varying too much (getting too warm).
Also would be a good idea to check the freezer temperature, should be 0 to 5 degrees F.