cross-posted from: https://possumpat.io/post/6398015

Hello everyone, I need a bit of help trying to make sure my idea makes sense.
Long story short I am converting my PC from air cooled to liquid cooled and need some help with filling up the coolant and avoiding air bubbles.

My idea is to use a brake bleeder to vacuum out the air from the custom loop then fill the loop with coolant.

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The first step is to have a bucket of coolant up high on a shelf so that gravity helps fill the whole system.
I will submerge the hose with the valve open to let out any air in the hose, then close the valve and lift out that end of the hose and connect it to the Y splitter.
This way there is no air in the first hose from the bucket. That alone I think would be enough to start pulling the coolant through and fill the case because of the suction and gravity.

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The second step would be to use the brake bleeder to vacuum out the air of the whole system. I am thinking like 10-15 psi should be good depending how much the soft hoses bend.
Once the air is out I will close the valve to the vacuum and slowly open the valve to the coolant to start filling the system.

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I connected the fill hose to a nipple fitting at the top of the reservoir/pump combo, and I connected the outlet port to the GPU block at the bottom.
I imagine it will pull the coolant to the GPU first as coolant falls into the reservoir, then through the radiator, and then back to the inlet port at the top. It will fill up above where the inlet tube is so that it is submerged to prevent any bubbles in the future as coolant is pumped through.

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My concerns are that normally you connect the inlet and outlet to the bottom of the water pump, and if needed there are additional inlet ports on the top of the reservoir.
I’m not sure if it matters that I use the top inlet only. The reason I switched to the top port was to try and make it make sense in my head on how the water would be sucked through when filling to avoid any air pockets in the radiator if it got sucked in from both ends.

The second concern is that my radiator is above the reservoir, on a car you usually fill the system from the top point on the radiator which is the highest spot.
It seems confusing to me on the PC to fill it from a lower point. I think vacuuming out the air will help with any issues but I’m not 100% sure.

info

I got the idea because a hose on my car recently failed so I started looking up videos on how to fill the coolant as I heard having bubbles can cause overheating, and using a vacuum seems to be the way to go.
https://www.youtube.com/watch?v=1beZZCBUnt0

I then started searching online on how to do the same thing for a PC and found some videos of people recently trying this, but it seems they both had some issues so I wanted to overcome that before trying it myself.
https://www.youtube.com/watch?v=SsJkmJMeL4w https://www.youtube.com/watch?v=aLu9RgmwzTU

I found this video in my research in trying to understand how liquid and gravity work which gave me the idea to have the fill bucket up high.

https://www.youtube.com/watch?v=CZmP0vsRBZ8