How to Check the Spray Arms
The pump/motor assembly pumps water up through the spray arms. The force of the water cause the arms to spin and spray the water and detergent mixture into the dish and glass racks. Some dishwashers have just one spray arm at the bottom in the tub, others have a second spray arm under or over the glass rack. Some dishwashers also have a spray tower that rises up out of the lower spray arm to concentrate an additional blast of water.
To access the bottom spray arm, remove the bottom dish rack. Reach in and spin the spray arms. They should spin freely. Lift up the spray arm from the end. There should some play in the arm allowing you to wobble it up and down. Inspect the seams of the arms for splits. If water sprays out of a seam, the dishes will not receive an adequate spray for proper cleansing and the force of the water directed at the door may cause leakage.
The lower spray arm may also have a spray tower. If it does, pull up the center part of it as far as it will extend and let it drop. It should lift and drop smoothly. You can also unscrew the tower by hand to inspect the interior for foreign objects that might clog it.
Remove the upper glass rack as necessary to access the upper spray arm. Repeat the steps above for the lower spray arm. The upper arm may not have as much wobble as the lower arm.
The water source for upper spray arm on some dishwashers may be through a tube which mates with the spray arm when the rack is pushed all the way back. Make sure that the rack is properly aligned with the water supply tube.
If necessary, the spray arm can be removed for cleaning or replacement. Unscrew the spray tower (if any) by hand and remove the bolt (if any) in the center of the spray arm. Otherwise lift and rock the spray arm until it comes off. Keep any washers in the same order as they are removed. To clean, soak it in warm water and rinse with a vigorous spray.