I had this broken KÜHLER H2O 620 closed loop water cooler that just didn't cool anymore. You could hear that there was air in the pump but it didn't seem to be leaking so I thought I could just take it apart, refill it and hopefully it would work again.

KÜHLER H2O 620

So I cut the tubes

tube cutting

And I started draining the radiator and..

radiator mucus

What the hell is that mucus in there??

more mucus

It smells worse than it looks.. either the chemicals they added to the coolant dissolved some kind of rubber in the radiator or something has gone wrong in the production. I'm going to refill it with distilled water later..

I also cleaned the pump/heat sink

the pump

This is when I realized that my tubes (which are actually aquarium tubes) were too large for the sockets so I had to keep some of the original tubes

tubes on the sockets

And put the new tubes over the old ones

new tubes over old ones

And seal them with zipties

zipties to seal

I did the same with the other end of the tubes (the ones that go in the pump)

pump connectors

And connected everything

tubes on the pump

The fun starts -> the filling

The radiator is taking a bath in distilled water after flushing out the rest of the mucus with normal water. Those freaking water bubbles never seem to go away.. after flushing for a few minutes there were still bubbles.

radiator in distilled water

Still bubbles..

bubbles.. bubbles everythere

After playing around for some time I was able to get the big bubbles out and only small ones near the output of the pump remained.. but I don't think that'll be a big problem.

finished.. sort of

Finished!

It worked like charm and the temperature chart speaks for itself

end product

the processor only has 15 degrees celsius

Okay I admit it.. 15°C was only because I opened the window.. but 32°C is also great