How can I reattach the upper sprinkler to my Bosch SHE43M02UC/48?

There is an indentation in the ceiling of my dishwasher where the upper sprinkler should be lodged, but it has somehow come undone and is sagging. The sprinkler head and arm is blocking the upper rack from sliding in and out. How can I reattach it to the ceiling? Do I just use waterproof glue? The part is labeled 601 in the Sears rack manual for this model. http://www.searspartsdirect.com/partsdirect/part-model/Bosch-Parts/Dishwasher-Parts/Model-SHE43M02UC48/1794/0130000/50031557/00006?blt=06&prst=0&shdMod=SHE43M02UC/48