[Gooserider]

Don't know if it is totally relevant, but I used to work in a photo lab, where we used alot of large mag drive pumps on the equipment, mostly because of the chemical issues. These were similar in construction to an Iwaki, where you had a magnetic cup attached to the motor spinning around the outside of a nylon housing, with a magnetically coupled rotor on a ceramic shaft inside the housing. We had several times when fluid flow to a pump was shut off for one reason or another, leading to pump failure.

My experience with those pumps at least was that the motor generally didn't get hurt. The failure process was that the rotor would heat up on the ceramic shaft until it seized onto the shaft, the shaft would then start spinning until it got hot enough to melt the nylon housing inside the drive cup. The nylon would sag onto the cup and get smeared all over it. By this time there was enough noise and stink to attract attention, or someone would notice that the fluid wasn't circulating....

As I said, the motor usually was OK, but the housing, rotor and shaft were trash. The cup was also considered trash until I started chucking them in a lathe and going in with a cutter to clean out the melted nylon. (At a replacement cost of $30 ea. vs. 20 minutes work to clean one up, this made me real popular with the boss...)

So if I inadvertently ran a pump dry, I'd reccomend dismantling the drive head and looking for melt damage. If none is found, then you may have lucked out.

Gooserider