While pre-filling the coolant system isn’t strictly necessary, it can help reduce spillage when removing modules—though some still choose to skip it. The essential tools for this step are a Rapidmate connector and a simple stick pump. You won’t eliminate all air pockets, but pre-filling can reduce the amount of G48 coolant needed during the air purge process that follows. There shouldn’t be any internal leaks at this stage, assuming the coolant system was pressure tested before sealing the pack.
