When replacing the EDP case drain filter is it sometimes easier to remove the complete assembly and installing it after replacement of the filter. However pay attention on how you install the assembly, because there is a check-valve installed on the housing. The arrow on the housing must point from OUTBOARD to INBOARD. If the housing is installed reversed, (and that is possible, the arrow is then no longer visible) than the EDP is not cooled because there is no case drain flow present resulting in a failing hydraulic pump. And that happens only after a while, during the first flight or during taxi out and possible not during the first testrun/dry-motoring which was done during maintenance.