Bosch dishwashers have two spray arms that enable the appliances to thoroughly clean dishes. One spray arm is located below each dish rack. Each spray arm has several nozzles that spray the dishes from below the rack. As part of the ongoing maintenance of your dishwasher, you should remove the spray arms and clean them to prevent built-up soap and hard water deposits from clogging the spray arms. If the top spray arm on your Bosch dishwasher is clogged or broken, you must remove it and either clean or replace it.
Open the dishwasher door, then pull the upper dish rack out to its fully extended position.
Rotate the plastic nut on the underside of the top spray arm clockwise, then remove the spray arm.
Use a pipe cleaner and brush to clean the spray arm, ensuring that the nozzles are not clogged.
Align the new or existing spray arm with the underside of the spray arm mounting bracket on the bottom of the rack.
Rotate the plastic nut counterclockwise until it's tight to secure the spray arm to the bottom of the dish rack.