Reservoir water level is slowly decreasing but cannot find any leak!

[BobbyBoyGaming]

Hello,

My reservoir water level is very very slowly decreasing, I did a air-pump leakage test prior to filling it with coolant, and the air pressure did not appear to decrease in 24 hours, however the air pressure gauge may not be sensitive enough.

I cannot see any leak anywhere nothing looks wet. Is it possible that the leak is so small that nothing ever looks wet because it dries up? or what can I do?

 

[Eddy]

No matter how well you bleed the system, you will still have air bubbles somewhere in the circuit. You will even have microbubbles on the inside of the hoses for a long time.
Even in my private system, it took months until all the air was really out of the system. My AGB was then also half empty.
As long as you don't find anything damp anywhere in the system, I wouldn't worry about it. Just go through it with tissues or something similar and you'll find damp spots very quickly.

 

[BobbyBoyGaming]

Ok I think this is microbubbles because I do see some small bubbles moving around in the reservoir even though I filled this loop several months ago.

I have learned that I should not throw away my remaining coolant next time...