Last year I replaced the motor on my Pentair WF-28 pump and replaced all seals. I took that motor off today and noticed some white residue on the bottom part of the motor behind the impeller and quite a bit on the underside of the motor as well causing the paint to peel.


I looked back at my old Pentair motor that I still have and it has bubbling paint in the same location although slightly harder to see in the photo.

so is this normal or a sign of an issue? Odd that it would be a shaft seal since I replaced that with the new motor and the signs of corrosion or whatever this is are the same on both motors with 2 different shaft seals. Also, my understanding of shaft seal issues is that I would see this all over the face of the motor, not just on the bottom. Could there be a problem with the seal plate itself? Or am I just being paranoid and this is perfectly normal signs of use?


I looked back at my old Pentair motor that I still have and it has bubbling paint in the same location although slightly harder to see in the photo.

so is this normal or a sign of an issue? Odd that it would be a shaft seal since I replaced that with the new motor and the signs of corrosion or whatever this is are the same on both motors with 2 different shaft seals. Also, my understanding of shaft seal issues is that I would see this all over the face of the motor, not just on the bottom. Could there be a problem with the seal plate itself? Or am I just being paranoid and this is perfectly normal signs of use?