I ordered a new Grundfos shallow well pump. When it arrived, I noticed the interior of the pump body was wet inside and covered in "grimy" black gunk. I installed the pump and it would hum but would not spin. I disassembled the pump body and found a fair amount of debris inside that appeared to be rust chunks and build-up of some kind. After cleaning it out and reassembling, the pump is working fine. I'm suspicious that this pump was either used, refurbished or was a return. I did not have time to deal with returning it and was concerned about the high shipping cost.