Air remaining in the liquid cooling system post-bleeding
Air remaining in the liquid cooling system post-bleeding
Hey everyone. First time posting here, so I want to thank the community. I've already received many answers from here before, that's really appreciated!
Now, regarding my question: I recently assembled my first liquid cooling setup. I'm a seasoned builder, but I haven't worked with liquid cooling before. My system includes a CPU loop, a Swiftech reservoir, an EKWB XTOP DDC 3.2 PWM Elite pump, a vertical-mounted 240 radiator, and an EKWB supremacy EVO CPU block. After assembling everything, filling it up, and running tests—including a leak check using a jumped power supply—I confirmed everything was functioning properly. (I did this in my kitchen with an open fill tube for atmospheric testing.)
Now I'm connecting the power supply, wiring it up, removing the fill tube, and sealing the reservoir. It's placed back in its case, turned on, and when it runs, there are numerous tiny air bubbles throughout the tubing. (Last night it was bubble-free while off.) When active, the pump is noticeably louder, but fluid circulation is present and the system remains stable.
My main concern is troubleshooting this setup. The system is reassembled, and I'm not fully confident about running it with the reservoir exposed at the top due to its high fill level. Also, I want to make sure it's safe to operate this way—while the pump appears to be moving fluid, I'm worried about potential air pockets or inefficiencies. I haven't noticed any leaks, and the fluid level remains steady.
Thanks in advance for your help!
well two things come to mind. first, you haven't removed all the air yet... there might be a leak drawing in air? it seems like everything is missing. [opinion] try using a makeup brush and powder such as talc or baby powder, dust it on, and let it sit overnight or for about 12 hours. then check if any powder has changed or looks wet—if not, it should be dry.
Updated: I attached the pump to an external jumped power supply. It ran for about 20 minutes and returned to its usual quiet operation, with no bubbles in the tubes when off. After unplugging the fan controller cable, it spiked back up and produced a lot of air bubbles. Since I kept the fan connector plugged in while running it at full speed, it likely ran at its minimum power. Should I bleed the system while the pump is operating at maximum? It appears the pump itself is responsible for the bubbles, which is making me quite puzzled.
It seems the main cause is the extremely high flow rate producing microbubbles. Reducing the RPM with PWM on the DDC or fan controller should resolve it. I've observed bubbles during full-speed operation for bleeding and leak testing. At lower speeds, they disappear within a few days.
You have the intake line at the bottom of the radiator, right? So it can't pull in any trapped air from there? Air goes up to the top?
It sounds like there might be a leak or a pinhole somewhere.
Just to add what the person above said, we must have posted at the same time—give it a few days running and check for bubbles that might 'stick' and indicate something loose is happening.
But the amount you say you see is a lot of stuck bubbles [opinion].
They mentioned unplugging the fan controller cable to force it to run at maximum speed, which caused the pump to increase volume and create many air bubbles. Yesterday while running it, they worried the pump might draw more water than the reservoir can supply, causing it to suck air in.
If you can control the pump speed, start it low and gradually increase it, watching for air bubbles. Once you notice them, reduce the speed a bit and see if everything works normally. If temperatures and cooling are normal, that could be the issue.