impeller seized

[chin_lee]

Hi Tunze
I've had my 6080 for a few years and I do clean it regularly. Last week the 6080 failed to restart and I opened it up to clean but the impeller magnet assembly would not come out. I soaked in vinegar for 6 days and tried taking the assembly out for each of the 6 days and it wouldnt' come out. Eventually one of the plastic parts broke during one of my attempts and since the assembly would have to be replaced, I decided I would drill out the plastic parts and take out the magnet. All the plastic parts in the core of the magnet are now gone and the magnet has cracked when I used a larger drill bit. But I still can't get the magnet out.
Please help - what can I do?

 

[rvitko]

Send it to me, basically it requires brute force but very carefully applied. I usually drill with increasingly larger bits going up 1/32" at a time. Eventually the magnet is so thin it kind of collapses and I just chisel out the remains. You have to be very careful to not drill through or cause excessive damage to the side walls or bush bearing seat. Some scratches are innevitable but you want to be as careful as possible. For the future, a trick that works 80% of the time is to unscrew the prop, put the pump in hot water (not to hot, like about 130 degrees F) or in the attic, somewhere hot so the plastic expands a bit and any water inside expands to push on the magnet. Grab the shaft with pliers with rubber tips and stand on the pump (I do this barefoot so I can feel if I am going to break something and put a towel underneath to avoid straining the cable too much) then pull straight up in a quick jerk and this should remove the magnet without damaging it. If it is a few years old it likely had the older drive unit that was more prone to calcium build up, several changes have about doubled how long it takes for this to happen.