1. Air Baffling: Remove any internal baffling that may exist inside the server that will impede the flow of the coolant. These are often plastic parts that are installed to guide high speed air through the server. These are not necessary and actually impede the fluid flow.
2. Hard Disks: Check any spinning hard drives and make sure they are sealed drives or remove them and replace with SSDs. Spinning drives have vent holes that allow the fluid into them, they won’t be harmed electronically but the platters and drive reading arms are not designed for the increased friction of the fluid.
4. Fans: If possible, remove as many fans as possible. They are not effective at moving the coolant and only waste energy. This may require a change in the BIOs to eliminate any alarms or automatic shut downs that occur when the fans are not present or cycling below their intended rotational speed. It may not be possible to shut off the fans on the power supplies, generally this isn’t a problem, so its ok to allow the PSU fans to run in fluid.