Closed Loop Coolers
No maintenance needed, only requires you to blow compressed air through the rad fins and do the usual cleaning job. Since its a sealed loop, you can't tear it down. The latter would defeat the purpose of it being a sealed all-in-one unit. However, you could remove the cooling plate and change/replace the TIM on the CPU to something like an Arctic Silver 5 , Timtronics or Arctic cooling's MX lineup.