Recently I was trying to debug my dishwasher. It was leaving crusty deposits of food particles and leftover detergent on all the glasses. It was pretty nasty.
I wanted to eliminate the possibility that there were just some leftover bits in the dishwasher that kept getting re-deposited on the dishes, so I took apart as much of the dishwasher as possible to clean out all the nooks and crannies.
When I got to the spray arm I was able to unscrew the whole thing by twisting the bottom post counter-clockwise. But this took the entire spray arm assembly loose and I couldn't really get to the inside of the arm where I could see there was plenty of caked-on dishwasher detergent. I'll spare you pictures of the gunk since it's kind of gross.
I noticed that the central top portion of the spray arm looked like it should detach but there was nothing that would allow me to grip it except for 4 small plastic posts. I knew if I tried to grip these with pliers or something I would just shred the plastic and ruin it.
So I thought I might be able to fashion something that would act as a custom wrench of sorts. I decided to try it with wood since I have lots of scrap wood available and the tools to work it.
I started by putting some blue chalk dust on the ends of each of the 4 plastic posts, then I pressed a chunk of 2x4 against the posts to transfer the marks. Then I went to the drill press and drilled holes where the chalk marks were on the 2x4. I noticed that there's a raised area in the middle so I used a forstner bit to drill out a recess in the 2x4 to fit.
I then tried it and it slid right over the posts and with a small clockwise twist the central part of the spray arm lifted free. Pictures of all of this are below.
So it goes to show if you're resourceful you can fashion your own custom tools, even if all you have available is an ugly chunk of wood.
|Dishwasher spray arm. Note the 4 plastic posts on the central portion. That's what we'll use to turn the center part.|
|Here's the "wrench" after machining the holes in the correct locations.|
|The "wrench" fits right on top|
|After turning the tool about half a turn clockwise the center portion detaches from the spray arm!|