computer cooling water pump disassembly

[squeaks]

This failed water pump was integrated with a bay reservoir for a computer cooling loop that I purchased in 2012. It provided tens of thousands of hours of faithful service, but one day it stopped spinning. I removed the pump from the reservoir, and applied 12V to the wires and the pump did not spin. I disassembled it which the pictures show. The rotor and shaft seemed to be in very good condition, as were the impeller and blades. I nonetheless cleaned them and reassembled. Applying 12V I noted a buzz and when attempting to jump start the pump or poke it, I did not have success. Once or twice the pump surprised me and ran for 0.5 seconds or so then stopped. Trying to turn the impeller by hand I found increasing resistance like it was teasing me with increasing danger. It was hard to turn the impeller with the intake cover on, but the intake cover supports the shaft and therefore helps maintain alignment of the rotor. I also applied force with a rubber mallet without success.

The pump draws about 0.5 Amp at 12V.

I notice that when turning the rotor by hand, it stops every 180 degrees.

I suspected one of the two sets of windings failed, or wiring or electronics related to a set of windings. so I tried to gain access to the internals with a dremel. It seems like the way this was constructed was there is a thin outter plastic shell and the internal parts were placed inside and then filled with some type of plastic that hardens. So none of the internal components seem to be accessible.

I found some youtube videos on small water pump disassembly that are mostly made by Indians. In most of their 'repairs' the rotor or internal area were contaminated with enough scaling to prevent the pump from rotating. This does not solve my problem. My pump was ran in distilled water and was very clean.

I am curious about what the internals are like, and am considering taking a hot air gun and trying to melt away the plastic. I'd prefer to end up with something like a good set of windings to play with if possible.

I know this is not economical but can anyone suggest how I could remove the plastic making the pump useless and boring? An acid maybe?

[TheMG]

It's most likely an epoxy based potting. Not much will touch it even heat won't really do much. Soaking in acetone might soften it a bit but will also ruin some things like the PVC wire insulation.