My liquid cooling system was an Antec, the pump was unreliable, but the CPU block and the radiator were great, so I kludged together a solution with some pumps from Princess Auto, but eventually they died, so I've now made a working pump using the pump parts from the PA pumps, and a PC fan. I replaced the shaft with one long enough to go through it, into the pump housing. I soldered the shaft to the magnet turner assembly, and then put it into the frame, and glued it to the fan blade/drive assembly. It's an older fan, so PWM control doesn't work, but if you got the right fan you'd be able to do it. This design of course is made to be adapted to W/E hardware you want to use, so have fun with it.
https://www.youtube.com/watch?v=LReq5XCWWeE
My Patreon: https://www.patreon.com/jontheinventor
I design 3D printable pocket pistols that can't be posted here, so I have them on Patreon.