My memory of the relationship between pumps and motors is that any motor can be used as a pump, but pumps must be modified in order to be used as motors. AvE has a video on this topic (beware of language - he does have a tendency to swear a bit, along with some crude jokes at times). Good info, regardless. One of the things he does on his channel is take things apart to show how they work (generally tools, but other small appliance-like things as well).
I believe the modification is a pressure seal on the shaft. He goes over it in the video.
https://youtu.be/TIGSBEUGYeU