I have a very small weep coming from where the radiator valve screws into the radiator itself and would like to have a go at fixing this myself. Is it possible to fix this whilst leaving the radiator in place on the wall? I was thinking of the following – isolate the radiator, undo the compression nut on the rad valve, drain the radiator, then unscrew the tail from the radiator. Remove existing PTFE and fit more, then reassemble. Would this be the correct way to do it, or does the radiator need to come off the wall?