Danner Mag Repair

[seaweed88]

I have a Mag 12A and an 18B which have started making a vibration noise. I have both pumps out of the sumps and the impellers out of the pumps. The magnets on the impellers are not marked up or grooved. The place the impeller goes is not damaged from what I can feel.
My question is will a new impeller fix the problem or do these pumps just wear out with time?
I don't understand the inner workings of these pumps. What makes them stop working?
Thanks Mark

 

[Nomadic1]

I haven't used a mag drive pump in a while, so I can't remember the internals -- do they have a shaft on the impeller? If they do, and the pump has been in service a while, it may be worn, or the grommets that hold the shaft in place may be deteriorated, allowing the magnet to wobble in the impeller well.

IF there is no shaft, there could also be a little play in there now, due to wear of the magnet spinning in there against plastic periodically. The wear may just be VERY UNIFORM, making things look normal.

I had both of those pumps on my first reef tank 10 years ago, and even brand new, I found them to be noisy -- from vibration, but they also seemed to cavitate quite a bit too. Since switching to an Eheim 1262 and an Aquamedic Oceanrunner 7 years ago, I have had silent bliss (just the resonant vibration one would expect, but this is reduced by using a foam pad under them in my sump). I also have heard reports from others that the Sicce return pump is silent (the one that Tunze rebrands as their own, but it is made by Sicce).